CN113206306B

CN113206306B - Battery protection device, battery pack and terminal

Info

Publication number: CN113206306B
Application number: CN202110396575.XA
Authority: CN
Inventors: 宋利军; 雷浩
Original assignee: Xi'an Wenxian Semiconductor Technology Co ltd
Current assignee: Xi'an Wenxian Semiconductor Technology Co ltd
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2023-08-01
Anticipated expiration: 2041-04-13
Also published as: CN113206306A

Abstract

A first aspect of an embodiment of the present application provides a battery protection device, including: a battery protection module; the switch tube chip comprises a main switch unit and a detection switch unit, wherein the main switch unit comprises a first main connecting end used for being connected with a battery cathode, a second main connecting end used for being connected with a load and a main control end connected with a switch control end; the detection switch unit comprises a first detection connecting end, a second detection connecting end and a detection control end connected with the switch control end, wherein the first detection connecting end is electrically connected with the second reference output end, and the second detection connecting end is electrically connected with the first reference output end; the overcurrent protection unit compares the voltage of the current sampling end with the voltage of the first reference output end or the voltage of the second reference output end to judge whether the current flowing through the main switch unit is abnormal or not. The application also provides a battery assembly and a terminal. The application has the advantages that: the cost is reduced, the safety and the precision are high, and the stability is realized.

Description

Battery protection device, battery pack and terminal

Technical Field

The application relates to the technical field of batteries, in particular to a battery protection device, a battery assembly and a terminal.

Background

The current quick charging of the terminal has become a common customer demand, the quick charging technology used by the terminal has become a current hot technology, but the heat generated by the quick charging is also a difficult problem in the whole industry, and when the charging current is increased by 1 time, the heat generated by the same charging loop impedance is changed to be 4 times.

When the common lithium ion battery used by some terminals is used, a protection circuit which is packaged in the battery and is connected with the battery core in series is needed to monitor the charge overvoltage, the discharge undervoltage, the charge overcurrent and the discharge overcurrent of the lithium ion battery, and the charge and discharge currents are required to meet the requirements of related specifications.

In the current detection method of the current battery protection device, the common method is to use the resistance and the impedance of a charge-discharge loop MOS tube to perform overcurrent detection, and trigger an overcurrent detection comparator in the lithium battery protection IC by using the voltage drop formed by the current flowing through the resistance of the charge-discharge loop MOS tube, but the resistance of the MOS tube is not a constant value and changes along with the change of various conditions, and when the high current realizes quick charge, the conduction voltage at two ends of the MOS tube is higher and the change range is larger, so that the resistance change of the MOS tube is also larger, and the requirement of high precision cannot be met.

In the current detection method of the current battery protection device, another common method is to specially set a high-precision current sampling resistor for a charge-discharge loop, use the current sampling resistor for overcurrent detection, and trigger an overcurrent detection comparator in the battery protection IC by using the voltage drop formed by the current flowing through the current sampling resistor of the charge-discharge loop.

However, since an additional current sampling resistor is introduced, the impedance of the charge-discharge loop is increased, and when high current realizes quick charge, the current sampling resistor also generates heat to cause the temperature rising effect of the charge-discharge loop to be obviously increased, which may cause a safety problem, and the high-precision current sampling resistor has higher cost.

Disclosure of Invention

The embodiment of the application aims to solve the technical problem of providing a battery protection device, a battery assembly and a terminal. It is possible to detect whether or not the current is abnormal during charge or/and discharge of the battery at low cost and with high accuracy.

To solve the above technical problem, a first aspect of an embodiment of the present application provides a battery protection device for protecting a battery connected to a load, including:

the battery protection module comprises a first power supply end, a second power supply end, an overcurrent protection unit, a switch control end, a first reference output end, a second reference output end, a current sampling end and a first constant current generation unit, wherein the first power supply end and the second power supply end are respectively used for being electrically connected with a positive electrode and a negative electrode of a battery, the overcurrent protection unit is respectively electrically connected with the current sampling end, the first reference output end and the second reference output end, and the first constant current generation unit is electrically connected with the first reference output end or the second reference output end;

The switch tube chip comprises a main switch unit and a detection switch unit, wherein the main switch unit comprises a first main connecting end used for being connected with a battery cathode, a second main connecting end used for being connected with the load, and a main control end connected with a switch control end; the detection switch unit comprises a first detection connecting end, a second detection connecting end and a detection control end connected with the switch control end, wherein the first detection connecting end is electrically connected with the second reference output end, and the second detection connecting end is electrically connected with the first reference output end;

the current sampling end is electrically connected with the second main connecting end, and the overcurrent protection unit compares the voltage of the current sampling end with the voltage of the first reference output end or the voltage of the second reference output end to judge whether the current flowing through the main switch unit is abnormal or not.

The battery protection module further comprises a second constant current generation unit, wherein the first constant current generation unit is electrically connected with the first reference output end, and the second constant current generation unit is electrically connected with the second reference output end;

the battery protection module further comprises a negative pressure generating unit, wherein the negative pressure generating unit is electrically connected with the first reference output end and is used for enabling the voltage of the first reference output end to be negative pressure;

When the battery is discharged, the overcurrent protection unit judges that the voltage of the current sampling end is greater than or equal to M times the voltage of the second reference output end, and the switch control end controls the discharge loop to be disconnected, wherein M is a positive integer; and when the overcurrent protection unit judges that the voltage of the current sampling end is greater than or equal to N times the voltage of the first reference output end when the battery is charged, the switch control end controls the charging loop to be disconnected, wherein N is a positive integer.

The battery protection module comprises a comparison loop selection unit, a first reference output end and a second reference output end are respectively and electrically connected with the comparison loop selection unit, wherein the overcurrent protection unit comprises a charging overcurrent protection unit and a discharging overcurrent protection unit;

the comparison loop selection unit is used for enabling the discharge overcurrent protection unit to compare the voltage of the first reference output end with the voltage of the current sampling end when the battery is discharged so as to judge whether the current flowing through the main switch unit is abnormal or not; the comparison loop selection unit is used for enabling the charging overcurrent protection unit to compare the voltage of the second reference output end with a preset voltage when the battery is charged so as to judge whether the current flowing through the main switch unit is abnormal or not.

The comparison loop selection unit comprises two first switches, two second switches and a charge/discharge comparator, wherein the output end of the first constant current generation unit is respectively and electrically connected with the input end of one of the first switches and the input end of one of the second switches, the output end of the first switch is respectively and electrically connected with a second reference output end and a charge overcurrent protection unit, the output end of the second switch is respectively and electrically connected with the first reference output end and the discharge overcurrent protection unit, the second reference output end is also electrically connected with the input end of the other second switch, the output end of the second switch is grounded, the output end of the first switch is also electrically connected with the input end of the other first switch, the output end of the first switch is electrically connected with the current sampling end, the other input end of the charge/discharge comparator is grounded, the output end of the charge/discharge comparator is respectively connected with the control ends of the two first switches and the control ends of the two second switches, and when the first switch is turned on or off, and when the second switch is turned on or off.

The battery protection module further comprises a single polarity conversion unit, one end of the single polarity conversion unit is electrically connected with the current sampling end, the other end of the single polarity conversion unit is electrically connected with the overcurrent protection unit, and when the voltage of the current sampling end is positive or negative, the single polarity conversion unit converts the voltage of the current sampling end into a voltage with the same polarity as the voltage of the first reference output end and sends the voltage to the overcurrent protection unit;

the overcurrent protection unit compares the voltage of the first reference output end with the voltage of the current sampling end to judge whether the current flowing through the main switch unit is abnormal or not;

and when the voltage of the current sampling end is positive and the voltage of the current sampling end is negative, the voltage polarity of the first reference output end is the same.

The switch control end comprises a charging control end and a discharging control end;

the main switch unit comprises a second switch tube group and a first switch tube group, the second switch tube group comprises a first main connecting end, a first discharging connecting end and a first discharging control end, the first switch tube group comprises a second main connecting end, a second charging connecting end and a second charging control end, wherein the first discharging connecting end is electrically connected with the second charging connecting end, the first discharging control end is electrically connected with the discharging control end, and the second charging control end is electrically connected with the charging control end.

The detection switch unit comprises a first detection switch tube group and a second detection switch tube group, wherein the first detection switch tube group comprises a first detection connecting end, a first middle connecting end and a first detection control end, the second detection switch tube group comprises a second detection connecting end, a second middle connecting end and a second detection control end, the first middle connecting end is electrically connected with the second middle connecting end, the first middle connecting end is electrically connected with the first discharge connecting end, the second middle connecting end is electrically connected with the second charge connecting end, and the first detection control end and the second detection control end are electrically connected with the charge control end or the discharge control end or the first detection control end and the second detection control end are respectively electrically connected with the charge control end, the discharge control end or the first detection control end and the second detection control end are respectively electrically connected with the discharge control end and the charge control end.

The detection switch unit comprises a first detection switch tube group and a second detection switch tube group, wherein the first detection switch tube group comprises a first detection connecting end, a first middle connecting end and a first detection control end, the second detection switch tube group comprises a second detection connecting end, a second middle connecting end and a second detection control end, the first middle connecting end is electrically connected with the second middle connecting end, and the first detection control end and the second detection control end are electrically connected with a charging control end or a discharging control end or the first detection control end and the second detection control end are electrically connected with the charging control end and the discharging control end respectively or the first detection control end and the second detection control end are electrically connected with the discharging control end and the charging control end respectively.

The detection switch unit comprises a detection switch Guan Guanzu, the detection switch tube group comprises a first detection connecting end, a second detection connecting end and a detection control end, and the detection control end is electrically connected with the discharge control end or the charge control end.

The main switch unit comprises a main switch tube group, wherein the main switch tube group comprises the first main connecting end, the second main connecting end and the main control end;

the main switch tube group further comprises a discharge body diode and a charge body diode, wherein the cathode of the discharge body diode is electrically connected with the first main connecting end, the anode of the charge body diode is electrically connected with the anode of the discharge body diode, and the cathode of the charge body diode is electrically connected with the second main connecting end;

the bias unit is electrically connected with the first main connecting end and the second main connecting end of the main switch tube group respectively, and is also electrically connected with the anode of the discharge body diode or the anode of the charge body diode, and the bias unit is used for controlling the substrate bias state of the main switch tube group.

The bias unit comprises a discharging sub-switch and a charging sub-switch, one end of the discharging sub-switch is electrically connected with the second main connecting end, the other end of the discharging sub-switch is electrically connected with the anode of the charging body diode, one end of the charging sub-switch is electrically connected with the first main connecting end, the other end of the charging sub-switch is electrically connected with the anode of the charging body diode, and the overcurrent protection unit is used for controlling the on-off of the charging sub-switch and the discharging sub-switch, wherein the discharging sub-switch is disconnected when the charging sub-switch is conducted, and the charging sub-switch is disconnected when the discharging sub-switch is conducted.

The detection switch unit comprises a first detection switch tube group and a second detection switch tube group, wherein the first detection switch tube group comprises a first detection connecting end, a first middle connecting end and a first detection control end, the second detection switch tube group comprises a second detection connecting end, a second middle connecting end and a second detection control end, the first middle connecting end is electrically connected with the second middle connecting end, the first middle connecting end and the second middle connecting end are electrically connected with the anode of the discharge body diode or the anode of the charge body diode, and the first detection control end and the second detection control end are electrically connected with the switch control end.

The main switch unit and the detection switch unit respectively comprise MOS (metal oxide semiconductor) tubes, and the MOS tubes are groove type metal oxide semiconductors or transverse metal oxide semiconductors.

A second aspect of embodiments of the present application provides a battery assembly, including:

a battery;

the battery protection device is characterized in that the first power end and the second power end of the battery protection device are respectively and electrically connected with the battery.

A third aspect of the embodiments of the present application provides a terminal, including:

A load;

the battery assembly described above;

wherein the battery controls power supply to the load via the battery protection device.

The implementation of the embodiment of the application has the following beneficial effects: the battery protection device comprises a switch tube chip, wherein the switch tube chip comprises a main switch unit and a detection switch unit, and the main switch unit comprises a first main connecting end used for being connected with a battery cathode, a second main connecting end used for being connected with the load and a main control end connected with a switch control end; the detection switch unit comprises a first detection connecting end, a second detection connecting end and a detection control end connected with the switch control end, wherein the first detection connecting end is electrically connected with the second reference output end, and the second detection connecting end is electrically connected with the first reference output end; the current sampling end is electrically connected with the second main connecting end, and the overcurrent protection unit compares the voltage of the current sampling end with the voltage of the first reference output end or the voltage of the second reference output end to judge whether the current flowing through the main switch unit is abnormal or not. Therefore, the detection resistor with high precision does not need to be arranged, the cost can be reduced, the reference current generated by the first constant current generation unit is far smaller than the charging current or the discharging current flowing by the main switch unit, and therefore the generated heat is little, and the safety problem cannot be caused. In addition, the current detection mode has higher precision and is not influenced by the environment.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic view of a battery assembly according to a first embodiment of the present application;

fig. 2 is a schematic view of a battery protection module according to a first embodiment of the present application;

FIG. 3 is a schematic diagram of a switching tube chip according to a first embodiment of the present application;

FIG. 4 is a schematic diagram of a switching tube chip according to a second embodiment of the present application;

fig. 5 is a schematic view of a battery protection module according to a second embodiment of the present application;

FIG. 6 is a schematic diagram of one implementation of a negative pressure generating unit according to a second embodiment of the present application;

FIG. 7 is a schematic diagram of another implementation of the negative pressure generating unit of the second embodiment of the present application;

fig. 8 is a schematic view of a battery assembly according to a third embodiment of the present application;

fig. 9 is a schematic view of a battery protection module according to a third embodiment of the present application;

FIG. 10 is a schematic diagram of a switching tube chip according to a third embodiment of the present application;

Fig. 11 is a schematic view of a battery protection module according to a fourth embodiment of the present application;

fig. 12 is a schematic diagram of a comparison circuit selection unit, a first constant current generation unit, and an overcurrent protection unit according to a fourth embodiment of the present application;

fig. 13 is a schematic view of a battery protection module according to a fifth embodiment of the present application;

fig. 14 is a schematic diagram of a switch die of a fifth embodiment of the present application;

fig. 15 is a schematic diagram of a single polarity conversion unit according to a fifth embodiment of the present application;

fig. 16 is a schematic view of a battery protection module according to a sixth embodiment of the present application;

FIG. 17 is a schematic diagram of a switch tube chip according to a sixth embodiment of the present application;

fig. 18 is a schematic diagram of a comparison circuit selection unit, a first constant current generation unit, and an overcurrent protection unit of a sixth embodiment of the present application;

fig. 19 is an equivalent schematic diagram of a comparison circuit selection unit, a first constant current generation unit, an overcurrent protection unit, and a switching tube chip when the battery of the sixth embodiment of the present application is discharged;

fig. 20 is an equivalent schematic diagram of a comparison circuit selection unit, a first constant current generation unit, an overcurrent protection unit, and a switching tube chip during battery charging according to a sixth embodiment of the present application;

fig. 21 is a schematic view of a battery assembly of a seventh embodiment of the present application;

Fig. 22 is a schematic diagram of a switching tube chip according to a seventh embodiment of the present application;

fig. 23 is a schematic view of a battery protection module according to a seventh embodiment of the present application;

FIG. 24 is a schematic diagram of a biasing unit of a seventh embodiment of the present application;

fig. 25 is a schematic view of a battery assembly according to an eighth embodiment of the present application;

description of the figure:

100-battery protection module; 110-an overcurrent protection unit; 111-a charging overcurrent protection unit; 112-a discharge overcurrent protection unit; 120-a control unit; 131-a first constant current generation unit; 132-a second constant current generation unit; 140-a negative pressure generating unit; 150-a voltage polarity matching unit; 151-charge/discharge comparator; 152-a charge switch; 153-discharge switch; 160-a single polarity switching unit; 170-a biasing unit; 171-discharging the electronic switch; 172-a charge sub-switch;

200-switching tube chips; 210-a main switching unit; 211-a first main connection; 212-a second main connection; 213—master control side; 220-a first switching tube group; 231-a first discharge connection; 232-a first discharge control terminal; 230-a second switching tube group; 221-a second charging connection; 222-a second charge control terminal; 240-main switch tube group; 241-a discharge body diode; 242-charge body diode; 243-biasing the connection; 244-a charge bias terminal; 245-a discharge bias terminal;

250-detecting a switching unit; 251-a first detection connection; 252-a second detection connection; 253-detection control terminal; 260-a first detection switch tube group; 261-a first intermediate connection; 262-a first detection control end; 270-a second detection switch tube group; 271-a second intermediate connection; 272-a second detection control terminal; 280-detecting a switch tube group;

310-cell; VDD-a first power supply terminal; VSS-a second power supply terminal; a CDO-switch control terminal; a CO-charge control terminal; a DO-discharge control terminal; VM-current sampling end; VMS-first reference output; VMP-second reference output; r1-a first resistor; r2-a second resistor; c1-a first capacitance; a BO-bias control terminal; BC-biasing the charging terminal; BD-biases the discharge terminal.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

The terms "comprising" and "having" and any variations thereof, as used in the specification, claims and drawings, are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or modules is not limited to only those steps or units listed but may alternatively include other steps or units not listed or inherent to such process, method, article, or apparatus. The terms and/or and are synonymous, are to be understood to encompass three schemes, for example, a scheme comprising A or/and B is to be understood to encompass three schemes of A, a scheme comprising B, a scheme comprising A and B. Furthermore, the terms "first," "second," and "third," etc. are used for distinguishing between different objects and not for describing a particular sequential order.

The embodiment of the application provides a terminal, which is a mobile phone, a tablet personal computer, a notebook computer and the like. Referring to fig. 1, the terminal includes a battery assembly and a load (not shown), for example, a microprocessor, a camera driving circuit, an image processor, a display panel, a touch screen, etc., the load is electrically connected to the battery assembly, the battery assembly is used for supplying power to the load, and two ends of the load are respectively electrically connected to two terminals of the battery assembly in fig. 1. The battery assembly includes a battery 310 and a battery protection device, the battery 310 also being generally referred to in the art as a battery cell, wherein the battery 310 may be a lithium battery or other battery, and the battery protection device includes a battery protection module 100 and a switching tube chip 200.

Specifically, the battery protection module 100 is electrically connected to the positive and negative electrodes of the battery 310, the load is electrically connected to the battery 310, the battery 310 supplies power to the battery protection module 100 and the load, and the battery protection module 100 protects the battery 310 from damage or load damage. In this embodiment, the number of the batteries 310 is one or more, and when the number is plural, the plurality of batteries 310 may be connected in parallel or in series-parallel, and the batteries 310 are preferably lithium batteries. In this embodiment, the battery protection module 100 controls the on or off of the switch tube chip 200, and the battery 310 supplies power to the load via the switch tube chip 200, that is, the battery protection module 100 controls the on or off of the switch tube chip 200, so as to control whether the battery 310 supplies power to the load. In this embodiment, a first resistor R1 and a first capacitor C1 are further disposed between the battery 310 and the battery protection module 100, and the first resistor R1 and the first capacitor C1 are disposed for filtering. In addition, in other embodiments of the present application, the first resistor R1 and the first capacitor C1 may not be disposed between the battery 310 and the battery protection module 100. In addition, in other embodiments of the present application, other circuits or electronic components may be provided between the battery 310 and the battery protection module 100. In this embodiment, the battery protection module 100 is located on the same chip. However, the present application is not limited thereto, and in other embodiments of the present application, the battery protection module 100 may not be located on the same chip or on a chip.

Referring to fig. 1 and 2 in combination, in this embodiment, the battery protection module 100 includes a first power supply terminal VDD, a second power supply terminal VSS, an over-current protection unit 110, a control unit 120, a switch control terminal, a first constant current generation unit 131, a current sampling terminal VM, and a first reference output terminal VMs, where the first power supply terminal VDD and the second power supply terminal VSS are electrically connected to the positive electrode and the negative electrode of the battery 310, respectively, in this embodiment, the second power supply terminal VSS is electrically grounded, the over-current protection unit 110 is electrically connected to the control unit 120, the current sampling terminal VM, and the first reference output terminal VMs, respectively, and the first constant current generation unit 131 is electrically connected to the first reference output terminal VMs, for generating a constant reference current output, which may be preset, and the constant reference current is output via the first reference output terminal VMs. The specific implementation manner of the first constant current generating unit 131 is a conventional technical means in the art, and will not be described herein.

Referring to fig. 1 and 3 in combination, in the present embodiment, the switch tube chip 200 includes a main switch unit 210 and a detection switch unit 250, where the main switch unit 210 and the detection switch unit 250 are located on the same chip, for example, on the same silicon chip, and are manufactured by the same process.

In this embodiment, the main switch unit 210 includes a first main connection terminal 211, a second main connection terminal 212, and a main control terminal, where the first main connection terminal 211 is electrically connected to the battery 310, specifically, to the negative electrode of the battery 310, that is, in this embodiment, the first main connection terminal 211 is grounded, the second main connection terminal 212 is electrically connected to the load, the main control terminal is electrically connected to the switch control terminal of the battery protection module 100, and the battery protection module 100 controls the on or off of the main switch unit 210 through the switch control terminal, and in this embodiment, the main switch unit 210 is used to control the battery 310 to discharge the load or charge the battery 310.

In this embodiment, the second main connection terminal 212 of the main switch unit 210 is further electrically connected to the current sampling terminal VM of the battery protection module 100, when the battery protection module 100 controls the main switch unit 210 to be turned on, the battery protection module 100 can collect the current flowing through the main switch unit 210 through the current sampling terminal VM, where the current may be the charging current or the discharging current.

In the present embodiment, the detection switch unit 250 includes a first detection connection terminal 251, a second detection connection terminal 252, and a detection control terminal 253. The first detection connection end 251 is electrically connected to the main switch unit 210 or the battery protection module 100, the second detection connection end 252 is electrically connected to the first reference output end VMS, and the detection control end 253 is electrically connected to the switch control end.

In this embodiment, the main switch unit 210 includes at least one set of MOS transistors, the set of MOS transistors includes a plurality of MOS transistors, the plurality of MOS transistors are connected in parallel, the detection switch unit 250 includes at least one set of MOS transistors, the set of MOS transistors includes a plurality of MOS transistors, the plurality of MOS transistors are connected in parallel, and the number of MOS transistors included in the main switch unit 210 is greater than the number of MOS transistors included in the detection switch unit 250. In addition, in other embodiments of the present application, the MOS transistors in the main switch unit 210 and the detecting switch unit 250 may be of other types.

In this embodiment, the main switch unit 210 and the detection switch unit 250 are located on the same silicon wafer, so that the on-resistance of each group of MOS transistors included in the main switch unit 210 is m1 times that of a single MOS transistor, and the on-resistance of each group of MOS transistors included in the detection switch unit 250 is m2 times that of a single MOS transistor, and because they are connected in parallel, in this embodiment, m1 and m2 satisfy: m1 and m2 are more than 0 and less than 1. Thus, the resistances of the main switch unit 210 and the detection switch unit 250 when turned on are proportional, for example, the ratio of the on-resistance of the detection switch unit 250 to the on-resistance of the main switch unit 210 is 2:1, 5:1, 10:1, 100:1, 200:1, 300:1, 400:1, 500:1, etc., preferably greater than 10:1, the ratio is determined after the switch tube chip 200 is fabricated, and since the main switch unit 210 and the detecting switch unit 250 are located on the same chip, the environments where the main switch unit 210 and the detecting switch unit 250 are located are identical, and the resistances of the two are changed at the same time, so that the ratio is not changed with the change of the environments.

In this embodiment, by designing the first constant current generating unit 131 to output a suitable reference current, generally, the reference current generated by the first constant current generating unit 131 is far smaller than the maximum charge current or the maximum discharge current allowed to flow when the main switch unit 210 is normally turned on, for example, 1/2, 1/5, 1/10, 1/50, 1/60, 1/70, 1/80, 1/90, 1/100, 1/200, 1/300, 1/400, 1/500, preferably, less than 1/10 of the maximum charge current or the maximum discharge current allowed to flow. Since the on-resistances of the main switch unit 210 and the detection switch unit 250 are in a proportional relationship, since the voltage is a product of the resistance and the current, the relationship between the maximum current allowed to flow on the main switch unit 210 and the reference current generated by the first constant current generation unit 131 can be obtained by comparing the on-voltages on the main switch unit 210 and the detection switch unit 250, the reference current can be designed as a threshold current by setting a proper reference current output, and it can be obtained whether the current flowing through the main switch unit 210 exceeds the set maximum current (maximum current allowed to flow) by comparing the voltage on the main switch unit 210 and the voltage on the detection switch unit 250, and if so, the main switch unit 210 is turned off to prevent the battery 310 from being damaged or prevent the load from being damaged. Therefore, the present application may not need to increase a detection resistor with high accuracy, so that the cost may be reduced, and the reference current generated by the first constant current generating unit 131 is far smaller than the charging current or the discharging current flowing through the main switch unit 210, so that the generated heat is also very small, and no safety problem is caused; and the reference current generated by the first constant current generation unit 131 can be controlled very precisely, so that the current detection is also very precise.

The following description refers to specific embodiments.

First embodiment

Fig. 1 is a schematic diagram of a battery assembly according to a first embodiment of the present application, please refer to fig. 1, in which a switching tube chip 200 can be used for detecting a discharge current of a battery 310.

Specifically, referring to fig. 1 and 3 in combination, in the present embodiment, the main switch unit 210 includes the first switch tube group 220 and the second switch tube group 230, and of course, in other embodiments of the present application, the switch tube groups included in the main switch unit 210 are not limited to two groups, and may include more switch tube groups according to actual needs. In this embodiment, the first switch tube group 220 includes a plurality of MOS transistors, in this embodiment, the plurality of MOS transistors in the first switch tube group 220 are connected in parallel, and the second switch tube group 230 includes a plurality of MOS transistors, in this embodiment, the plurality of MOS transistors in the second switch tube group 230 are connected in parallel. In addition, in other embodiments of the present application, the multiple MOS transistors in the first switch tube group 220 and the multiple MOS transistors in the second switch tube group 230 may be connected in series, or both in series and parallel, and may be adjusted according to actual needs or process needs. In this embodiment, the MOS transistors included in the first switch tube set 220 and the second switch tube set 230 are Trench metal oxide semiconductor field effect transistors (Trench MOS), and all the drain electrodes of the MOS transistors are required to be connected together, and the advantage of using the MOS transistors is that: has lower on-resistance and gate-drain charge density, and thus lower on and switching loss and faster switching speed. However, the present application is not limited thereto, and in other embodiments of the present application, other MOS transistors may be used by those skilled in the art.

In this embodiment, the switch control terminal includes a charge control terminal CO and a discharge control terminal DO, and the charge control terminal CO and the discharge control terminal DO are electrically connected to the control unit 120 respectively. The second switch tube group 230 includes the first main connection terminal 211, the first discharge connection terminal 231, and the first discharge control terminal 232, and the first switch tube group 220 includes the second main connection terminal 212, the second charge connection terminal 221, and the second charge control terminal 222. The first main connection terminal 211 is electrically connected to the negative electrode of the battery 310, the first discharging connection terminal 231 is electrically connected to the second charging connection terminal 221, the second main connection terminal 212 is electrically connected to the load, the first discharging control terminal 232 is electrically connected to the discharging control terminal DO, and the second charging control terminal 222 is electrically connected to the charging control terminal CO. In the present embodiment, the first discharging connection terminal 231 is the drain of the second switch tube group 230, and the second charging connection terminal 221 is the drain of the first switch tube group 220. In the present embodiment, when the battery 310 has a discharging abnormality, the discharging control terminal DO controls the second switching tube group 230 to be turned off at this time, and when the battery 310 has a charging abnormality, the charging control terminal CO controls the first switching tube group 220 to be turned off at this time, thereby protecting. When the battery protection module 100 controls the first switch bank 220 to be turned off through the charge control terminal CO, the charging circuit of the battery 310 is turned off, the battery 310 cannot be charged, and when the second switch bank 230 is turned on, the battery 310 can be discharged; when the battery protection module 100 controls the second switching stack 230 to be turned off through the discharge control terminal DO, the discharge loop of the battery 310 is turned off, the battery 310 cannot discharge the load, and the battery 310 may be charged when the first switching stack 220 is turned on. Generally, in normal operation, the battery protection module 100 controls both the first switch bank 220 and the second switch bank 230 to be turned on.

In the present embodiment, the detection switch unit 250 includes one detection switch Guan Guanzu 280, but the present application is not limited thereto, and in other embodiments of the present application, more switch tube groups may be included as needed. In the present embodiment, the detection switch tube group 280 includes a plurality of MOS transistors, and in the present embodiment, the plurality of MOS transistors in the detection switch tube group 280 are connected in parallel. In addition, in other embodiments of the present application, a plurality of MOS transistors in the detection switch tube set 280 may be connected in series, or both in series and parallel, and may be adjusted according to actual needs or process needs. In this embodiment, the MOS transistor included in the detection switch tube set 280 is a Trench metal oxide semiconductor field effect transistor (Trench MOS), and all the drains on the same chip are connected together by the MOS transistor. However, the present application is not limited thereto, and in other embodiments of the present application, other MOS transistors may be used by those skilled in the art. In this embodiment, all the MOS transistors included in the switch transistor chip 200 are of the same type, so that the manufacture is convenient, and the same parameters and the same manufacturing environment are used during the manufacture, so that the characteristics of the obtained MOS transistors are the same. In this embodiment, all the MOS transistors included in the switching transistor chip 200 are trench mosfet transistors. In addition, in other embodiments of the present application, all the MOS transistors included in the switch transistor chip 200 may be other types of MOS transistors.

In the present embodiment, the detection switch tube group 280 includes a first detection connection terminal 251, a second detection connection terminal 252, and a detection control terminal 253. The first detection connection end 251 is electrically connected to the first discharge connection end 231 or the second charge connection end 221, the second detection connection end 252 is electrically connected to the first reference output end VMS, the detection control end 253 can be electrically connected to the charge control end CO or the discharge control end DO under a general condition, and is optimally electrically connected to the discharge control end DO, at this time, even if an abnormality occurs and thus the battery cannot be charged, the discharge control end DO can still control the second switch tube group 230 and the detection switch tube group 280 to be turned on, at this time, normal discharge can be performed, and the battery protection module 100 can determine whether the discharge of the battery 310 is abnormal. In the present embodiment, the first detection connection terminal 251 is the drain electrode of the detection switch tube group 280, so that the drains of the second switch tube group 230, the first switch tube group 220, and the detection switch tube group 280 on the switch tube chip 200 are all connected together.

In this embodiment, if the current flowing through the main switching unit 210 just occurs abnormality when the battery 310 is discharged by making the first constant current generating unit 131 generate an appropriate reference current, the voltage of the current sampling terminal VM is equal to N times the voltage of the first reference output terminal VMs, so that the overcurrent protection unit 110 can determine whether the current flowing through the main switching unit 210 is abnormal by comparing the voltage of the first reference output terminal VMs with the voltage of the current sampling terminal VM. Where N is a positive integer, for example, N is 1, 2, 3, 4, 5, 6, 7, 8, 9, etc., in this embodiment N is 1, that is, the voltage of the current sampling terminal VM is equal to the voltage of the first reference output terminal VMs when an abnormality occurs.

Specifically, in the present embodiment, when the battery protection module 100 controls the main switch unit 210 and the detection switch unit 250 to be turned on, the battery 310 discharges at this time, and the voltage of the current sampling terminal VM is positive, then:

uvm =iout (rpedam+rbharge) +u0;

uvms=iref+iout+rjput+u0;

wherein Uvm is the voltage of the current sampling terminal VM, iout is the current flowing through the first switch tube group 220 and the second switch tube group 230 when the battery 310 discharges, R is the resistance when the second switch tube group 230 is turned on, and R is the resistance when the first switch tube group 220 is turned on; u0 is the voltage at the first main connection 211 of the second switch tube group 230, and due to the ground, uvms is the voltage at the first reference output VMS in this embodiment, iref is the reference current generated by the first constant current generating unit 131 (where Iref is much smaller than Iout), and R is the resistance when the detection switch tube group 280 is turned on.

In this embodiment, since the second switch tube group 230, the first switch tube group 220 and the detection switch tube group 280 are all located on the same chip, that is, on the same silicon wafer, that is, all manufactured by the same process, the resistances among the three are proportional, and the specific proportional value is proportional to the number of MOS transistors included in each of the second switch tube group 230, the first switch tube group 220 and the detection switch tube group 280, assuming that:

Rjie=k1×rjie, rjie=k2×rjie;

wherein, K1 and K2 are proportionality coefficients and are constants.

In this embodiment, when the current flowing through the main switch unit 210 just has an abnormality while the battery 310 is discharged, and the voltage of the current sampling terminal VM is equal to the voltage of the first reference output terminal VMs, then:

uvm =iout (R-put+r-fill) +u0=iref+iout-R-put+u0=uvms;

and (3) performing calculation to obtain:

iout x R charge = Iref x R check;

iout=iref_rcetection/rcharge;

Iout＝Iref*K1；

since K1 is a constant and does not change with the use environment, the discharge current Iout is in a proportional relationship with the reference current Iref of the first reference output terminal VMS, and further, by making the first constant current generation unit 131 generate an appropriate reference current Iref, the magnitude of the discharge current can be controlled, and the reference current can be controlled very precisely, so that the accuracy of 1% can be achieved, and thus, whether an abnormality, such as discharge overcurrent, occurs when the battery 310 discharges can be determined very precisely. For example, when the maximum discharge current needs to be controlled, a suitable reference current value may be selected when the battery protection module 100 is designed, and when the battery protection module 100 obtains that the voltage of the current sampling terminal VM is equal to or greater than the voltage of the first reference output terminal VMs through comparison, the battery protection module 100 may know that the discharge current exceeds the threshold, and at this time, the battery protection module 100 may control the second switch tube group 230 to be turned off through the discharge control terminal DO, so as to realize protection.

In this embodiment, since the resistances of the MOS transistors included in the first switch tube group 220, the second switch tube group 230, and the detection switch unit 250 all change with the external environment, for example, increase or decrease simultaneously, so that K is a constant and cannot change with the external environment, for example, change in temperature, the usage environment of the battery protection module 100 of this embodiment is relatively wide, and the discharge current can be controlled relatively accurately.

In general, the first constant current generation unit 131 outputs a reference current to the first reference output terminal VMS when the voltage of the first reference output terminal VMS is positive, as conventionally understood by those skilled in the art.

In addition, in other embodiments of the present application, the MOS transistors in the first switch tube group 220, the second switch tube group 230, and the detection switch unit 250 are NMOS transistors. In addition, in other embodiments of the present application, the MOS transistors in the first switch tube group 220, the second switch tube group 230, and the detection switch unit 250 may also be PMOS transistors.

Second embodiment

Fig. 4 is a schematic diagram of a switching tube chip according to a second embodiment of the present application, please refer to fig. 4, in which the switching tube chip 200 can be used for detecting the charging current of the battery 310.

In this embodiment, as in the first embodiment, the main switch unit 210 includes a first switch tube group 220 and a second switch tube group 230, and the switch control terminal of the battery protection module 100 includes a charge control terminal CO for controlling on or off of the first switch tube group 220 and a discharge control terminal DO for controlling on or off of the second switch tube group 230.

In this embodiment, the detection switch unit 250 includes a detection switch tube set 280, and the connection manner of the detection switch tube set 280 is mainly the same as that of the first embodiment, and will not be described herein. In this embodiment, the detection control terminal 253 of the detection switch tube set 280 may be electrically connected to the charge control terminal CO or the discharge control terminal DO under a general condition, and is preferably electrically connected to the charge control terminal CO, where the charge control terminal CO may control the first switch tube set 220 and the detection switch unit 250 to be turned on even when an abnormality occurs and thus the discharge is disabled, and the battery protection module 100 may determine whether the charge of the battery 310 is abnormal.

The inventors of the present application found that, when the battery 310 is charged, since the negative terminal of the battery 310 is grounded, the voltage of the current sampling terminal VM is negative, so that the voltage of the first reference output terminal VMs and the voltage of the current sampling terminal VM need to be the same in polarity, and in this embodiment, the voltage of the first reference output terminal VMs is also designed to be negative, and the voltage of the first reference output terminal VMs and the voltage of the current sampling terminal VM can be compared.

In order to realize that the voltage of the first reference output terminal VMS is a negative voltage, please refer to fig. 5, in this embodiment, the battery protection module 100 includes a negative voltage generating unit 140, the negative voltage generating unit 140 is electrically connected to the first reference output terminal VMS, please refer to fig. 6, fig. 6 includes the negative voltage generating unit 140 and the first constant current generating unit 131, in this embodiment, one implementation circuit of the negative voltage generating unit 140 is a charge pump, in fig. 6, the charge pump is a common charge pump (in the illustration, the switches S1 and S2 are controlled by an oscillator), and how the negative voltage generated by the first reference output terminal VMS is relatively conventional through the circuit in fig. 6 is not described herein. In addition, in other embodiments of the present application, the negative pressure generating unit 140 is not limited to the circuit in fig. 6, and a person skilled in the art may also realize the generation of negative pressure by other charge pumps or other circuits, please refer to fig. 7, fig. 7 is another charge pump (wherein Vclk1, vclk2 are alternately high level VDD and low level VSS, when Vclk1 is high level VDD, vclk2 is low level VSS, in this state, S1 and S4 are turned on, S2 and S3 are turned off, when Vclk1 is low level VSS, vclk2 is high level VDD, in this state, S1 and S4 are turned off, and S2 and S3 are turned on), and how the charge pump generates negative pressure at the first reference output terminal VMS is relatively conventional, which will not be described herein. Of course, the person skilled in the art may generate the negative pressure in other ways, and the key point of this embodiment is that the inventor of the present application finds that the first reference output terminal VMS needs to provide a negative pressure to enable the voltage of the current sampling terminal VM to be compared with the voltage of the first reference output terminal VMS during charging.

Referring to fig. 1, fig. 4, and fig. 5, in this embodiment, if the current flowing through the main switch unit 210 just has an abnormality when the battery 310 is charged by making the first constant current generating unit 131 generate a suitable reference current, the voltage of the current sampling terminal VM is equal to N times the voltage of the first reference output terminal VMs, so that the overcurrent protection unit 110 may determine that the current is abnormal. Where N is a positive integer, for example, N is 1, 2, 3, 4, 5, 6, 7, 8, 9, etc., in this embodiment N is 1, that is, the voltage of the current sampling terminal VM is equal to the voltage of the first reference output terminal VMs when an abnormality occurs.

Specifically, in the present embodiment, when the battery protection module 100 controls the main switch unit 210 and the detection switch unit 250 to be turned on, the battery 310 is charged, and at this time, the voltage of the current sampling terminal VM is negative, then:

uvm = -Iin (r+r+u 0);

uvms= -Iref x R check-Iin x R release + U0;

wherein Uvm is the voltage of the current sampling terminal VM, iin is the current flowing through the first switch bank 220 and the second switch bank 230 when the battery 310 is charged, R is the resistance when the second switch bank 230 is turned on, and R is the resistance when the first switch bank 220 is turned on; u0 is the voltage at the first main connection 211 of the second switch tube group 230, and due to the ground, uvms is the voltage at the first reference output VMS in this embodiment, iref is the reference current generated by the first constant current generating unit 131 (where Iref is much smaller than Iin), and R is the resistance when the detection switch tube group 280 is turned on.

rjie=k1×rjie, rjie=k2×rjie;

wherein, K1 and K2 are proportionality coefficients and are constants.

In this embodiment, when the current flowing through the main switch unit 210 just has an abnormality while the battery 310 is charged, and the voltage of the current sampling terminal VM is equal to the voltage of the first reference output terminal VMs, then:

uvm = -Iin (R-put + R-fill) +u0 = -Iref = -Iin R-put + u0 = Uvms;

and (3) performing calculation to obtain:

iin R charge=iref R check;

iin=iref check/charge;

Iin＝Iref*K1；

since K1 is a constant and does not change with the use environment, the charging current Iin is in a proportional relationship with the reference current Iref of the first reference output terminal VMS, and further, by making the first constant current generating unit 131 generate an appropriate reference current, the magnitude of the discharging current can be controlled, and since the reference current can be controlled very precisely, the accuracy of 1% can be achieved, and thus, the magnitude of the charging current can be controlled very precisely, and it can be very precisely determined whether an abnormality occurs when the battery 310 is charged, for example, an overcharge. For example, when the maximum charging current needs to be controlled, a suitable reference current value may be selected when the battery protection module 100 is designed, and when the battery protection module 100 obtains that the voltage of the current sampling terminal VM is equal to or greater than the voltage of the first reference output terminal VMs through comparison, the battery protection module 100 may know that the charging current exceeds the threshold value, and at this moment, the battery protection module 100 may control the first switch tube group 220 to be turned off through the charging control terminal CO, so as to realize protection.

In this embodiment, since the resistances of the MOS transistors included in the first switch tube group 220, the second switch tube group 230, and the detection switch unit 250 all change with the external environment, for example, increase or decrease simultaneously, so that K1 and K2 are constants and do not change with the external environment, for example, change in temperature, the usage environment to which the battery protection module 100 of this embodiment is applicable is relatively wide, and the charging current can be controlled relatively accurately.

In this embodiment, the MOS transistors in the first switch tube set 220, the second switch tube set 230, and the detection switch unit 250 are trench mosfet transistors. However, the present application is not limited thereto, and in other embodiments of the present application, the MOS transistors in the first switch tube group 220, the second switch tube group 230, and the detection switch unit 250 are NMOS transistors. In addition, in other embodiments of the present application, the MOS transistors in the first switch tube group 220, the second switch tube group 230, and the detection switch unit 250 are PMOS transistors.

Third embodiment

Fig. 8 is a schematic diagram of a battery assembly according to a third embodiment of the present application, please refer to fig. 8-10, in which the main switch unit 210 and the detecting switch unit 250 can be used for detecting the discharging current of the battery 310 or the charging current of the battery 310.

In the present embodiment, the battery protection module 100 includes a first reference output terminal VMS and a second reference output terminal VMP, wherein a first detection connection terminal 251 of the detection switch unit 250 is electrically connected to the second reference output terminal VMP of the battery protection module 100, and a second detection connection terminal 252 of the detection switch unit 250 is electrically connected to the first reference output terminal VMS of the battery protection module 100.

In the present embodiment, the detection switch unit 250 includes the first detection switch tube group 260 and the second detection switch tube group 270, and of course, in other embodiments of the present application, the detection switch unit 250 includes switch tube groups not limited to two groups, but may include more switch tube groups. In this embodiment, the first detection switch tube group 260 includes a plurality of MOS transistors, in this embodiment, the plurality of MOS transistors in the first detection switch tube group 260 are connected in parallel, and the second detection switch tube group 270 includes a plurality of MOS transistors, in this embodiment, the plurality of MOS transistors in the second detection switch tube group 270 are connected in parallel. In addition, in other embodiments of the present application, the plurality of MOS transistors in the first detection switch tube group 260 and the plurality of MOS transistors in the second detection switch tube group 270 may be connected in series, or both in series and parallel. In this embodiment, the MOS transistors included in the first detection switch tube group 260 and the second detection switch tube group 270 are Trench metal oxide semiconductor field effect transistors (Trench MOS), and all the drain electrodes of the MOS transistors are required to be connected together, and the advantage of using the MOS transistors is that: has lower on-resistance and gate-drain charge density, and thus lower on and switching loss and faster switching speed. However, the present application is not limited thereto, and in other embodiments of the present application, other MOS transistors may be used by those skilled in the art.

In the present embodiment, the first detection switch tube group 260 includes a first detection connection end 251, a first intermediate connection end 261, and a first detection control end 262, and the second detection switch tube group 270 includes a second detection connection end 252, a second intermediate connection end 271, and a second detection control end 272. The first detection connection end 251 is electrically connected to the second reference output end VMP, the first intermediate connection end 261 is electrically connected to the second intermediate connection end 271, the second detection connection end 252 is electrically connected to the first reference output end VMS, the first detection control end 262 and the second detection control end 272 are electrically connected to the charging control end CO or the discharging control end DO, or the first detection control end 262 and the second detection control end 272 are electrically connected to the charging control end CO and the discharging control end DO, or the first detection control end 262 and the second detection control end 272 are electrically connected to the discharging control end DO and the charging control end CO, respectively. In the present embodiment, the first intermediate connection end 261 is the drain of the first detection switch tube group 260, the second intermediate connection end 271 is the drain of the second detection switch tube group 270, and the first intermediate connection end 261, the second intermediate connection end 271, the first discharge connection end 231 of the second switch tube group 230, and the second charge connection end 221 of the first switch tube group 220 are all electrically connected together.

In this embodiment, the battery protection module 100 further includes a second constant current generating unit 132, where the first constant current generating unit 131 generates a first reference current, and the second constant current generating unit 132 generates a second reference current, and the magnitudes of the first reference current and the second reference current may be the same or different, and specifically set according to the actual situation. In the present embodiment, the first constant current generation unit 131 is electrically connected to the first reference output terminal VMS, and the second constant current generation unit 132 is electrically connected to the second reference output terminal VMP.

In this embodiment, the battery protection module 100 includes a negative pressure generating unit 140, the negative pressure generating unit 140 is electrically connected to the first reference output terminal VMS, the negative pressure generating unit 140 is configured to make the voltage of the first reference output terminal VMS be negative, and the specific circuit of the negative pressure generating unit 140 can be referred to the second embodiment, which is not described herein. In this embodiment, the voltage of the second reference output terminal VMP is positive, and the details of the first embodiment will not be described herein. In this embodiment, the main switch unit 210 and the detection switch unit 250 may be used for detecting the discharge current of the battery 310 or the charge current of the battery 310.

Specifically, in the present embodiment, when the battery 310 is discharged, by causing the second constant current generation unit 132 to generate an appropriate second reference current as in the first embodiment, when the battery 310 is discharged abnormally, the voltage of the current sampling terminal VM is equal to M times the voltage of the second reference output terminal VMP, and thus the overcurrent protection unit 110 can perform abnormality determination. Where M is a positive integer, for example, N is 1, 2, 3, 4, 5, 6, 7, 8, 9, etc., in this embodiment, M is 1, that is, the voltage of the current sampling terminal VM is equal to the voltage of the second reference output terminal VMP when an abnormality occurs.

uvm put=iout (R put+r fill) +u0;

uvmp=iref2×r1+iout×rput+u0;

the Uvm is the voltage of the current sampling terminal VM when the battery 310 discharges, iout is the current flowing through the first switch tube group 220 and the second switch tube group 230 when the battery 310 discharges, R is the resistance when the second switch tube group 230 is turned on, and R is the resistance when the first switch tube group 220 is turned on; u0 is the voltage at the first main connection 211 of the second switch tube group 230, uvmp is the voltage at the second reference output VMP due to the ground, uvmp is 0 in this embodiment, iref2 is the second reference current (Iref 1 is much smaller than Iout) output by the second constant current generating unit 132 through the second reference output VMP, and rce 1 is the resistance when the first detection switch tube group 260 is turned on.

In this embodiment, since the second switch tube group 230, the first switch tube group 220, the first detection switch tube group 260, and the second detection switch tube group 270 are all located on the same chip, that is, on the same silicon wafer, that is, are all fabricated by the same process, the resistances between the four are proportional, and the specific proportional value is proportional to the number of MOS transistors included in each of the second switch tube group 230, the first switch tube group 220, the first detection switch tube group 260, and the second detection switch tube group 270, assuming that:

rj1=k3×rjc, rj1=k4×rjc; rj2=k5 xeq, rjg2=k6×rj;

wherein, K3, K4, K5 and K6 are proportionality coefficients and are constants.

In the present embodiment, when the current flowing through the main switching unit 210 just has an abnormality while the battery 310 is discharging, the voltage of the current sampling terminal VM is equal to the voltage of the second reference output terminal VMP at this time, and is obtained by calculation:

Iout＝Iref2*K3；

since K3 is a constant and does not change with the use environment, the discharge current Iout is in a proportional relationship with the second reference current Iref2 of the second reference output terminal VMP, and further, by making the second constant current generating unit 132 generate an appropriate second reference current, the magnitude of the discharge current can be controlled, and the second reference current can be controlled very precisely, which can achieve 1% accuracy, so that it can be very precisely determined whether an abnormality, such as discharge overcurrent, occurs when the battery 310 discharges.

Also, in the present embodiment, when the battery 310 is charged, by making the first constant current generation unit 131 generate the appropriate first reference current as in the second embodiment, when the battery 310 is abnormally charged, the voltage of the current sampling terminal VM is equal to N times the voltage of the first reference output terminal VMs, and thus the overcurrent protection unit 110 can perform abnormality determination. Where N is a positive integer, for example, N is 1, 2, 3, 4, 5, 6, 7, 8, 9, etc., in this embodiment N is 1, that is, the voltage of the current sampling terminal VM is equal to the voltage of the first reference output terminal VMs when an abnormality occurs.

Specifically, in the present embodiment, when the battery protection module 100 controls the main switch unit 210 and the detection switch unit 250 to be turned on, the battery 310 is charged at this time, and the voltage of the current sampling terminal VM is negative, then:

uvm charge= -Iin (r+r+u0);

uvms= -iref1×rjc 2-iin×rjc+u0;

wherein Uvm is the voltage of the current sampling terminal VM when the battery 310 is charged, iin is the current flowing through the first switch bank 220 and the second switch bank 230 when the battery 310 is charged, R is the resistance when the second switch bank 230 is turned on, and R is the resistance when the first switch bank 220 is turned on; u0 is the voltage at the first main connection 211 of the second switch tube group 230, uvms is the voltage of the first reference output VMS due to the ground, in this embodiment 0, iref1 is the first reference current (in which Iref1 is much smaller than Iin) output by the first constant current generating unit 131 through the first reference output VMS, and rce 2 is the resistance when the second detection switch tube group 270 is turned on.

rj1=k3×rjc, rj1=k4×rjc; rj2=k5 xeq, rjg2=k6×rj;

wherein K3, K4, K5 and K6 are proportionality coefficients and are constants, R is 1/L or L times of on-resistance of a single MOS tube, R is 2, R is charged and R is discharged, wherein L is a natural number.

In the present embodiment, when the current flowing through the main switch unit 210 just has an abnormality while the battery 310 is charged, the voltage of the current sampling terminal VM is equal to the voltage of the first reference output terminal VMs, and is obtained by calculation at this time:

Iin＝Iref1*K5；

since K5 is a constant and does not change with the use environment, the charging current Iin is in a proportional relationship with the first reference current Iref1 of the first reference output terminal VMS, and further, by making the first constant current generating unit 131 generate a suitable first reference current, the magnitude of the charging current can be controlled, and the first reference current can be controlled very precisely, which can achieve 1% precision, so that it can be very precisely determined whether an abnormality, such as charging overcurrent, occurs when the battery 310 is charged.

In this embodiment, the over-current protection unit 110 determines whether the battery 310 is charged or discharged abnormally according to the comparison between the voltage of the current sampling terminal VM and the voltages of the first and second reference output terminals VMs and VMP, respectively.

In this embodiment, the MOS transistors in the first switch tube group 220, the second switch tube group 230, the first detection switch tube group 260, and the second detection switch tube group 270 are trench mosfet. However, the present application is not limited thereto, and in other embodiments of the present application, the MOS transistors in the first switch tube group 220, the second switch tube group 230, the first detection switch tube group 260, and the second detection switch tube group 270 are NMOS transistors. In addition, in other embodiments of the present application, the MOS transistors in the first switch tube group 220, the second switch tube group 230, the first detection switch tube group 260, and the second detection switch tube group 270 are PMOS transistors.

Fourth embodiment

Fig. 11 is a schematic diagram of a battery protection module according to a fourth embodiment of the present application, please refer to fig. 11, 12, 1, and 3 (or fig. 4), in which the main switch unit 210 and the detection switch unit 250 can be used for detecting the discharge current of the battery 310 or the charge current of the battery 310.

In this embodiment, the detection switch unit 250 includes a detection switch tube set 280, and the connection manner of the detection switch tube set 280 is mainly the same as that of the first embodiment, and will not be described herein. In the present embodiment, the detection control terminal 253 of the detection switch tube group 280 may be electrically connected to the charge control terminal CO or the discharge control terminal DO in a general case, and is electrically connected to the charge control terminal CO in the drawing.

In this embodiment, the battery protection module 100 includes a voltage polarity matching unit 150, and the first reference output terminal VMS is electrically connected to the voltage polarity matching unit 150, and the voltage polarity matching unit 150 is used to control the positive and negative of the voltage at the first reference output terminal VMS. Specifically, when the voltage polarity matching unit 150 determines that the battery 310 is charged, the voltage polarity matching unit 150 controls the voltage of the first reference output terminal VMS to be negative voltage at this time, and when the voltage polarity matching unit 150 determines that the battery 310 is discharged, the voltage polarity matching unit 150 controls the voltage of the reference output terminal to be positive voltage at this time.

In order to achieve charge-discharge matching between the voltage polarity matching unit 150 and the battery 310, please refer to fig. 12, referring to fig. 12, in this embodiment, the voltage polarity matching unit 150 includes a second constant current generating unit 132, a negative voltage generating unit 140, a charge/discharge comparator 151, a charge switch 152, a discharge switch 153, and an inverter, wherein the first constant current generating unit 131 is electrically connected to an input terminal of the discharge switch 153, an output terminal of the discharge switch 153 is electrically connected to a first reference output terminal VMS, a control terminal of the discharge switch 153 is electrically connected to the charge/discharge comparator 151, the negative voltage generating unit 140 is electrically connected to the second constant current generating unit 132, the second constant current generating unit 132 is electrically connected to one end of the charge switch 152, the other end of the charge switch 152 is electrically connected to the first reference output terminal VMS, and a control terminal of the charge switch 152 is electrically connected to the charge/discharge comparator 151. In this embodiment, the reverse end of the charge/discharge comparator 151 is grounded, the same-direction end of the charge/discharge comparator 151 is electrically connected to the current sampling end VM, and the output end of the charge/discharge comparator 151 is electrically connected to the control end of the charge switch 152 and the control end of the discharge switch 153 after passing through the inverter, respectively. In addition, the specific implementation of the voltage polarity matching unit 150 is not limited to fig. 12, and one skilled in the art may also implement voltage matching by other circuits. In the present embodiment, the magnitude between the first reference current generated by the first constant current generating unit 131 and the second reference current generated by the second constant current generating unit 132 is not limited, and may be set according to the actual situation, for example, the first reference current and the second reference current may be the same or different.

In this embodiment, when the battery 310 discharges, the voltage of the current sampling terminal VM is positive, the voltage of the same directional terminal of the charge/discharge comparator 151 is greater than the voltage of the opposite directional terminal, the output terminal of the charge/discharge comparator 151 controls the discharge switch 153 to be turned on, the charge switch 152 to be turned off, and the voltage of the first reference output terminal VMs is positive; when the battery 310 is charged, the voltage at the current sampling terminal VM is negative, the voltage at the same direction terminal of the charge/discharge comparator 151 is smaller than the voltage at the opposite direction terminal, the output terminal of the charge/discharge comparator 151 controls the discharge switch 153 to be turned off, and the charge switch 152 to be turned on, and the voltage at the first reference output terminal VMs is negative.

In this embodiment, the specific implementation manner of the negative pressure generating unit 140 can be referred to the second embodiment, and will not be described herein.

Referring to fig. 11 and 12, in this embodiment, when the battery 310 discharges, the voltage polarity matching unit 150 makes the voltage of the first reference output terminal VMS positive, and as in the previous embodiment, by making the first constant current generating unit 131 generate the appropriate first reference current, when the battery 310 discharges abnormally, the voltage of the current sampling terminal VM is equal to N times the voltage of the first reference output terminal VMS, so that the overcurrent protection unit 110 can determine that the battery is abnormally. Where N is a positive integer, for example, N is 1, 2, 3, 4, 5, 6, 7, 8, 9, etc., in this embodiment N is 1, that is, the voltage of the current sampling terminal VM is equal to the voltage of the first reference output terminal VMs when an abnormality occurs.

uvm put=iout (R put+r fill) +u0;

uvms=iref1×rcete+iout×rpput+u0;

the Uvm is the voltage of the current sampling terminal VM when the battery 310 discharges, iout is the current flowing through the first switch tube group 220 and the second switch tube group 230 when the battery 310 discharges, R is the resistance when the second switch tube group 230 is turned on, and R is the resistance when the first switch tube group 220 is turned on; u0 is the voltage at the first main connection 211 of the second switch tube group 230, and due to the ground, uvms is the voltage at the first reference output VMS in this embodiment, iref1 is the first reference current (Iref 1 is far smaller than Iout) output by the first reference output VMS, and R is the resistance when the detection switch tube group 280 is turned on.

Also assume:

rjie=k1×rjie, rjie=k2×rjie;

wherein, K1 and K2 are proportionality coefficients and are constants.

In the present embodiment, when the current flowing through the main switching unit 210 just has an abnormality while the battery 310 is discharging, the voltage of the current sampling terminal VM is equal to the voltage of the first reference output terminal VMs at this time, and is obtained through calculation:

Iout＝Iref1*K1；

Also, in the present embodiment, when the battery 310 is charged, the voltage polarity matching unit 150 makes the voltage of the first reference output terminal VMS negative, and by making the second constant current generating unit 132 generate the appropriate second reference current, as in the previous embodiment, when the battery 310 is abnormally charged, the voltage of the current sampling terminal VM is equal to N times the voltage of the first reference output terminal VMS, and thus the overcurrent protection unit 110 can perform abnormality determination. Where N is a positive integer, for example, N is 1, 2, 3, 4, 5, 6, 7, 8, 9, etc., in this embodiment N is 1, that is, the voltage of the current sampling terminal VM is equal to the voltage of the first reference output terminal VMs when an abnormality occurs.

uvm charge= -Iin (r+r+u0);

uvms= -iref2 x R check-Iin x R release + U0;

wherein Uvm is the voltage of the current sampling terminal VM when the battery 310 is charged, iin is the current flowing through the first switch bank 220 and the second switch bank 230 when the battery 310 is charged, R is the resistance when the second switch bank 230 is turned on, and R is the resistance when the first switch bank 220 is turned on; u0 is the voltage at the first main connection 211 of the second switch tube group 230, and due to the ground, uvms is the voltage at the first reference output VMS in this embodiment, iref2 is the second reference current (wherein Iref2 is much smaller than Iout) output by the second reference output VMP, and R is the resistance when the detection switch tube group 280 is turned on.

Also assume:

rjie=k1×rjie, rjie=k2×rjie;

wherein, K1 and K2 are proportionality coefficients and are constants.

Iin＝Iref2*K1；

in this embodiment, the battery protection module 100 has one less port than the third embodiment, so that the cost can be reduced.

Fifth embodiment

Fig. 13 is a schematic diagram of a battery protection module according to a fifth embodiment of the present application, please refer to fig. 13, 14, 15, and 1, in which the main switch unit 210 and the detection switch unit 250 can be used for detecting the discharging current of the battery 310 or the charging current of the battery 310.

In this embodiment, similar to the third embodiment, the main switch unit 210 includes a first switch tube group 220 and a second switch tube group 230, the switch control terminal of the battery protection module 100 includes a charge control terminal CO and a discharge control terminal DO, the signal of the charge control terminal CO is used to control the on or off of the first switch tube group 220, and the signal of the discharge control terminal DO is used to control the on or off of the second switch tube group 230. In the present embodiment, the detection switch unit 250 includes a first detection switch tube group 260 and a second detection switch tube group 270, the first detection switch tube group 260 includes a first detection connection end 251, a first intermediate connection end 261, a first detection control end 262, and the second detection switch tube group 270 includes a second detection connection end 252, a second intermediate connection end 271, and a second detection control end 272. The first detection connection end 251 is electrically connected to the first main connection end 211, the first intermediate connection end 261 is electrically connected to the second intermediate connection end 271, the second detection connection end 252 is electrically connected to the first reference output end VMS, the first detection control end 262 and the second detection control end 272 are electrically connected to the charging control end CO or the discharging control end DO, or the first detection control end 262 and the second detection control end 272 are electrically connected to the charging control end CO and the discharging control end DO, or the first detection control end 262 and the second detection control end 272 are electrically connected to the discharging control end DO and the charging control end CO, respectively. Unlike the third embodiment, in the present embodiment, the first and second intermediate connection terminals 261 and 271 are not shorted with the first and second discharge connection terminals 231 and 221. In addition, in other embodiments of the present application, the detection switch unit 250 may also include only one detection switch tube group.

In the present embodiment, the first switch tube group 220, the second switch tube group 230, the first detection switch tube group 260, and the second detection switch tube group 270 each include a plurality of MOS transistors, and in the present embodiment, the plurality of MOS transistors in the first switch tube group 220, the second switch tube group 230, the first detection switch tube group 260, and the second detection switch tube group 270 are connected in parallel. In addition, in other embodiments of the present application, the plurality of MOS transistors in the first switch tube group 220, the second switch tube group 230, the first detection switch tube group 260, and the second detection switch tube group 270 may be connected in series, or both in series and in parallel. In this embodiment, the MOS transistors included in the first switch tube group 220, the second switch tube group 230, the first detection switch tube group 260, and the second detection switch tube group 270 are lateral metal oxide semiconductor field effect transistors (lateral MOS), and the drains of these MOS transistors are not connected together. However, the present application is not limited thereto, and in other embodiments of the present application, other MOS transistors may be used by those skilled in the art.

In this embodiment, the battery protection module 100 includes a single polarity conversion unit 160, one end of the single polarity conversion unit 160 is electrically connected to the current sampling end VM, the other end of the single polarity conversion unit 160 is electrically connected to the overcurrent protection unit 110, the single polarity conversion unit 160 is configured to convert the voltage of the current sampling end VM into a voltage with the same polarity, that is, whether the voltage of the current sampling end VM is positive or negative, the voltage is uniformly converted into positive or uniformly converted into negative after being converted by the single polarity conversion unit 160, the polarity of the converted voltage is the same as that of the voltage of the first reference output end VMs, and the magnitude of the converted voltage is unchanged from that of the voltage before conversion; namely: when the voltage of the first reference output terminal VMS is constant at a positive voltage, the voltage of the current sampling terminal VM is at the positive voltage when the battery 310 is discharged, and the voltage is still at the positive voltage after passing through the single polarity conversion unit 160, and the voltage of the current sampling terminal VM is at the negative voltage when the battery 310 is charged, and the voltage is converted into the positive voltage after passing through the single polarity conversion unit 160; when the voltage of the first reference output terminal VMS is constant to be negative, the voltage of the current sampling terminal VM is positive when the battery 310 is discharged, and is converted to be negative after passing through the single polarity conversion unit 160, and the voltage of the current sampling terminal VM is negative when the battery 310 is charged, and is still negative after passing through the single polarity conversion unit 160. Since the voltage of the current sampling terminal VM is converted by the single polarity conversion unit 160, the polarity thereof is identical to that of the voltage of the first reference output terminal VMs, so that the two voltages can be compared.

Fig. 15 is a schematic diagram of an implementation of the single polarity switching unit 160, and the circuit of fig. 15 is a relatively conventional circuit in the art, so the principle thereof will not be described herein. Those skilled in the art may implement the single polarity conversion unit 160 by other conventional circuits.

With continued reference to fig. 13, in this embodiment, the voltage of the current sampling terminal VM is converted by the single polarity conversion unit 160 to be identical to the voltage of the first reference output terminal VMs, for example, positive voltage in this embodiment, so that the first constant current generation unit 131 generates a suitable first reference current as in the previous embodiment, and when the battery 310 is abnormally charged or discharged, the voltage of the current sampling terminal VM is equal to N times the voltage of the first reference output terminal VMs, so that the overcurrent protection unit 110 can perform abnormality judgment. Where N is a positive integer, for example, N is 1, 2, 3, 4, 5, 6, 7, 8, 9, etc., in this embodiment N is 1, that is, the voltage of the current sampling terminal VM is equal to the voltage of the first reference output terminal VMs when an abnormality occurs.

Specifically, in the present embodiment, when the battery protection module 100 controls the main switch unit 210 and the detection switch unit 250 to be turned on, no matter the battery 310 is charged or discharged, the voltage of the current sampling terminal VM is converted to positive voltage by the single polarity conversion unit 160, and then:

Uvm' =iio (rpole+rbole) +u0;

uvms=iref1 (rcept1+rcept2) +u0;

wherein Uvm' is the voltage of the current sampling terminal VM after being converted by the single polarity converting unit 160, iio is the current flowing through the first switch tube group 220 and the second switch tube group 230 when the battery 310 is charged or discharged, R is the resistance when the second switch tube group 230 is turned on, and R is the resistance when the first switch tube group 220 is turned on; u0 is the voltage at the first main connection 211 of the second switch tube group 230, since it is grounded, in this embodiment 0, uvms is the voltage of the first reference output terminal VMS, iref1 is the first reference current outputted by the first reference output terminal VMS (where Iref1 is much smaller than Iout), rce 1 is the resistance when the first detection switch tube group 260 is turned on, and rce 2 is the resistance when the second detection switch tube group 270 is turned on.

Rjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjjjjjjrjj;

where K7 is a scaling factor and is a constant.

In this embodiment, when the current flowing through the main switch unit 210 just has an abnormality when the battery 310 is charged or discharged, the voltage of the current sampling terminal VM is converted to be equal to the voltage of the first reference output terminal VMs, and the voltage is calculated to obtain:

Iio＝Iref1*K7

since K7 is a constant and does not change with the use environment, the charging current or the discharging current Iio is in a proportional relationship with the first reference current Iref1 of the first reference output terminal VMS, and further, by making the first constant current generating unit 131 generate a suitable first reference current, the magnitude of the charging current or the discharging current can be controlled, and the first reference current can be controlled very precisely, which can achieve 1% precision, so that it can be very precisely determined whether the current is abnormal when the battery 310 is charged or discharged.

In the present embodiment, the overcurrent protection unit 110 can determine whether the battery 310 is charged and the battery 310 is discharged abnormally according to the comparison between the voltage of the converted current sampling terminal VM and the voltage of the first reference output terminal VMs.

In this embodiment, the MOS transistors in the first switch tube group 220, the second switch tube group 230, the first detection switch tube group 260, and the second detection switch tube group 270 are lateral MOS field effect transistors. However, the present application is not limited thereto, and in other embodiments of the present application, the MOS transistors in the first switch tube group 220, the second switch tube group 230, the first detection switch tube group 260, and the second detection switch tube group 270 are NMOS transistors. In addition, in other embodiments of the present application, the MOS transistors in the first switch tube group 220, the second switch tube group 230, the first detection switch tube group 260, and the second detection switch tube group 270 are PMOS transistors.

Sixth embodiment

Fig. 16 is a schematic diagram of a battery protection module according to a sixth embodiment of the present application, please refer to fig. 16, 17, 18, and 8, in which the main switch unit 210 and the detection switch unit 250 can be used for detecting the discharge current of the battery 310 or the charge current of the battery 310.

In this embodiment, the specific configuration of the main switch unit 210 and the detection switch unit 250 is please see the fifth embodiment, unlike the fifth embodiment, in this embodiment, the battery protection module 100 includes a first reference output terminal VMS and a second reference output terminal VMP, wherein the first detection connection terminal 251 of the first detection switch tube group 260 is electrically connected to the second reference output terminal VMP, and the second detection connection terminal 252 of the second detection switch tube group 270 is electrically connected to the first reference output terminal VMS. In addition, in other embodiments of the present application, the detection switch unit 250 may also include only one switch tube group.

In this embodiment, the battery protection module 100 further includes a comparison loop selection unit 180, where the first reference output terminal VMS, the second reference output terminal VMP, and the first constant current generation unit 131 are electrically connected to the comparison loop selection unit 180, respectively, and the comparison loop selection unit 180 is configured to control how the voltages of the first reference output terminal VMS and the second reference output terminal VMP are compared with the voltage of the current sampling terminal VM when the battery 310 is charged or discharged. Specifically, when the comparison circuit selecting unit 180 determines that the battery 310 is charged, the voltage of the second reference output terminal VMP is selected by the comparison circuit selecting unit 180 and compared with a preset voltage, and when the comparison circuit selecting unit 180 determines that the battery 310 is discharged, the voltage of the first reference output terminal VMS is selected by the comparison circuit selecting unit 180 and compared with the voltage of the current sampling terminal VM.

To achieve charge-discharge matching of the comparison circuit selection unit 180 and the battery 310, please refer to fig. 18 for a specific implementation of the comparison circuit selection unit 180, the first constant current generation unit 131, and the over-current protection unit 110, please refer to fig. 18, in which the comparison circuit selection unit 180 includes two first switches T1, two second switches T2, and a charge/discharge comparator 151, and in which the over-current protection unit 110 includes a charge over-current protection unit (OCC) 111 and a discharge over-current protection unit (ODC) 112. The output end of the first constant current generating unit 131 is electrically connected to the input end of the first switch T1 and the input end of the second switch T2, the output end of the first switch T1 is electrically connected to the second reference output end VMP, the second reference output end VMP is further electrically connected to one input end of the charge overcurrent protecting unit 111, the output end of the second switch T2 is electrically connected to the first reference output end VMS, the first reference output end VMS is further electrically connected to one input end of the discharge overcurrent protecting unit 112, the second reference output end VMP is further electrically connected to the input end of the other second switch T2, the first reference output end VMS is further electrically connected to the input end of the other first switch T1, the output end of the second switch T2 is grounded, the output end of the first switch T1 is electrically connected to the current sampling end VM, the current sampling end is respectively electrically connected to one input end of the discharge overcurrent protecting unit 112 and the charge/discharge comparator 151, the other input end of the charge/discharge comparator 151 is grounded, the other input end of the charge/discharge comparator 151 is electrically connected to the two opposite ends of the second switch T2, and the output ends of the charge/discharge comparator 151 are electrically connected to the opposite control ends of the two control ends of the charge/discharge comparator 151. Thus, the two first switches T1 are turned on and off simultaneously, the two second switches T2 are turned on and off simultaneously, and the second switch T2 is turned off when the first switch T1 is turned on, and the first switch T1 is turned off when the second switch T2 is turned on. In this embodiment, the other input terminal of the charging overcurrent protection unit 111 is connected to a preset voltage.

In this embodiment, the first constant current generating unit 131 is electrically connected to the first reference output terminal VMS or the second reference output terminal VMP, specifically, the first constant current generating unit 131 is electrically connected to the first reference output terminal VMS and the second reference output terminal VMP in a time sharing manner.

In this embodiment, when the battery 310 discharges, the charge/discharge comparator 151 compares the voltage of the current sampling terminal VM with the ground voltage, and outputs a low level or a high level, in this embodiment, outputs a high level, so that the charge/discharge comparator 151 controls the two second switches T2 to be turned on and the two first switches T1 to be turned off, and the circuit diagram is as shown in fig. 19, and the same calculation process as in the previous embodiment, the circuit diagram is obtained:

uvm put=iout (R put+r fill) +0;

uvms=iref1 (rcept1+rcept2) +0;

the Uvm is the voltage of the current sampling terminal VM when the battery 310 discharges, iout is the current flowing through the first switch tube group 220 and the second switch tube group 230 when the battery 310 discharges, R is the resistance when the second switch tube group 230 is turned on, and R is the resistance when the first switch tube group 220 is turned on; uvms is the voltage of the first reference output terminal VMS, iref1 is the first reference current generated by the first constant current generating unit 131 (Iref 1 is far smaller than Iout), rcetection 1 is the resistance when the first detection switch tube group 260 is turned on, and rcetection 2 is the resistance when the second detection switch tube group 270 is turned on.

In this embodiment, since the second switch tube group 230, the first switch tube group 220, the first detection switch tube group 260, and the second detection switch tube group 270 are all located on the same chip, that is, on the same silicon wafer, that is, all manufactured by the same process, the resistances among the four are proportional, and specific proportional values are proportional to the number of MOS transistors included in each of the second switch tube group 230, the first switch tube group 220, the first detection switch tube group 260, and the second detection switch tube group 270, and the resistances of R-put, R-charge, R-check 1, and R-check 2 are proportional to the on resistance of a single MOS transistor, so that the resistance of (R-put+r-charge) is necessarily proportional to the resistance of (R-check 1+r-check 2), assuming that:

rjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjjjjjjrjj;

where K7 is a scaling factor and is a constant.

In this embodiment, when the current flowing through the main switch unit 210 just has an abnormality when the battery 310 is discharged, the discharge overcurrent protection unit 110 obtains that the voltage of the current sampling terminal VM is equal to the voltage of the first reference output terminal VMs, and the voltage is obtained through calculation:

Iout＝Iref1*K7

in this embodiment, when the battery 310 is charged, the charge/discharge comparator 151 compares the voltage of the current sampling terminal VM with the ground voltage, and outputs a low level or a high level, in this embodiment, outputs a low level, so that the charge/discharge comparator 151 controls the two second switches T2 to be turned off and the two first switches T1 to be turned on, and the circuit diagram is as shown in fig. 20, and the same calculation process as in the previous embodiment, the circuit diagram is obtained:

Uvm charge= -Iin (r+r+0);

uvmp=uvms+iref1 (rnst 1+rnst 2);

wherein Uvm is the voltage of the current sampling terminal VM when the battery 310 is charged, iin is the current flowing through the first switch bank 220 and the second switch bank 230 when the battery 310 is charged, R is the resistance when the second switch bank 230 is turned on, and R is the resistance when the first switch bank 220 is turned on; uvms is the voltage of the first reference output terminal VMS, uvmp is the voltage of the second reference output terminal VMP, iref1 is the first reference current (Iref 1 is far smaller than Iout) generated by the first constant current generating unit 131, rcetection 1 is the resistance when the first detection switch tube group 260 is turned on, and rcetection 2 is the resistance when the second detection switch tube group 270 is turned on.

In this embodiment, since the second reference output terminal VMP is shorted to the current sampling terminal VM, the following is achieved:

uvms= Uvm charge;

then: uvmp= -Iin (R-put+r-fill) +iref1 x (r3+r4);

Rjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjrjjjjjjrjj;

where K7 is a scaling factor and is a constant.

In this embodiment, when the current flowing through the main switching unit 210 just has an abnormality while the battery 310 is charged, the voltage at Uvmp is 0 at this time, and the charging overcurrent protection unit 110 triggers charging protection, and is obtained through calculation at this time:

Iin＝Iref1*K7。

in this embodiment, one input end of the charging over-current protection unit 111 is connected to the second reference output end VMP, and the other input end of the charging over-current protection unit 111 is connected to a preset voltage, which is 0V in this embodiment, that is, to ground, so that the charging over-current protection unit 111 can determine whether the charging current is abnormal by comparing the voltage of the second reference output end VMP with a preset voltage. In addition, in other embodiments of the present application, the preset voltage may be other than 0V, and this may be set according to the actual situation.

Seventh embodiment

Fig. 21 is a schematic diagram of a battery assembly according to a seventh embodiment of the present application, please refer to fig. 21, 22 and 23, wherein the main difference between the present embodiment and the previous embodiment is the main switch unit 210, and the main switch unit 210 of the present embodiment has low cost, smaller on-resistance and smaller on-loss.

Referring to fig. 21 and 22, in the present embodiment, the main switch unit 210 includes a main switch stack 240, and the main switch stack 240 includes a first main connection terminal 211 connected to a negative electrode of the battery 310, a second main connection terminal 212 connected to a load, and a main control terminal 213 connected to a switch control terminal CDO, and the second main connection terminal 212 is also electrically connected to a current sampling terminal VM of the battery protection module 100.

In this embodiment, the main switch tube set 240 further includes a charge body diode 242 and a discharge body diode 241, where a cathode of the charge body diode 242 is electrically connected to the second main connection terminal 212, an anode of the charge body diode 242 is electrically connected to an anode of the discharge body diode 241, and a cathode of the discharge body diode 241 is electrically connected to the first main connection terminal 211.

In this embodiment, the main switch tube set 240 further includes a bias connection terminal 243, a charge bias terminal 244, and a discharge bias terminal 245, wherein the bias connection terminal 243 is electrically connected to the anode of the charge body diode 242 and the anode of the discharge body diode 241, the charge bias terminal 244 is electrically connected to the first main connection terminal 211, and the discharge bias terminal 245 is electrically connected to the second main connection terminal 212.

Referring to fig. 23, in the present embodiment, the battery protection module 100 further includes a biasing unit 170, and the biasing unit 170 is used to control the substrate bias state of the main switch tube group 240. In the present embodiment, the bias unit 170 is electrically connected to the bias connection terminal 243 of the main switch stack 240 for switching the substrate connection path of the main switch stack 240 such that the substrate of the main switch stack 240 is biased to the negative power supply terminal of the battery 310 during discharging and the substrate of the main switch stack 240 is biased to the load terminal during charging. In addition, in other embodiments of the present application, the bias unit 170 may also be disposed in the switching tube chip 200.

Specifically, referring to fig. 23 and 24 in combination, in the present embodiment, the bias unit 170 includes a discharge sub-switch 171 and a charge sub-switch 172, a bias discharge end BD of the discharge sub-switch 171 is electrically connected to the second main connection end 212, an end of the discharge sub-switch 171 opposite to the bias discharge end BD is electrically connected to the bias control end BO, a bias charge end BC of the charge sub-switch 172 is electrically connected to the first main connection end 211, an end of the charge sub-switch 172 opposite to the bias charge end BC is electrically connected to the bias control end BO, and the bias control end BO is electrically connected to the bias connection end 243. The control terminal of the discharge sub-switch 171 and the control terminal of the charge sub-switch 172 are electrically connected to the overcurrent protection unit 110. In the present embodiment, the discharge sub-switch 171 is turned off when the charge sub-switch 172 is turned on, and the charge sub-switch 172 is turned off when the discharge sub-switch 171 is turned on. In this embodiment, the charging sub-switch 172 and the discharging sub-switch 171 may also be turned off at the same time (for example, when the main switch bank 240 is operating normally), and the charging sub-switch 172 and the discharging sub-switch 171 may not be turned on at the same time.

In the present embodiment, the charge and discharge of the battery 310 can be controlled by the main switching unit 210. Specifically, when the battery 310 is normally charged and discharged, the switch control terminal CDO of the battery protection module 100 controls the main switch bank 240 to be turned on, and at this time, the charging sub-switch 172 and the discharging sub-switch 171 are both turned off, thereby realizing the normal charging and discharging of the battery 310; when the battery 310 discharges abnormally, the switch control end CDO controls the main switch tube group 240 to be turned off, the charging electronic switch 172 is turned on, the discharging electronic switch 171 is turned off, and the battery 310 can form a loop through the charging electronic switch 172 and the charging body diode 242 at this time, so that normal charging can be realized, and the discharging electronic switch 171 and the main switch tube group 240 are turned off, so that discharging cannot be performed; when the battery 310 is abnormally charged, the switch control terminal CDO controls the main switch bank 240 to be turned off, the discharging sub-switch 171 is turned on, the charging sub-switch 172 is turned off, and the battery 310 can form a loop through the discharging sub-switch 171 and the discharging body diode 241, so that normal discharging can be realized, and the battery 310 cannot be charged due to the fact that the charging sub-switch 172 is turned off from the main switch bank 240. Thereby realizing the control of the charge and discharge of the battery 310.

In this embodiment, the charging and discharging control of the battery 310 can be realized by matching one main switch tube group 240 with the bias unit 170, and compared with the previous two switch tube groups, the cost is low, the on-resistance is smaller, and the on-loss is smaller.

In this embodiment, the main switch tube group 240 includes a plurality of MOS transistors connected in parallel. In addition, in other embodiments of the present application, multiple MOS transistors in the main switch tube set 240 may be connected in series, or both in series and parallel. In this embodiment, the discharging sub-switch 171 and the charging sub-switch 172 are MOS transistors, and the types of the MOS transistors may be the same as or different from those of the main switch tube group 240. In this embodiment, the MOS transistor in the main switch tube set 240 is a Trench metal oxide semiconductor field effect transistor (Trench MOS). However, the present application is not limited thereto, and in other embodiments of the present application, the MOS transistor in the main switch tube group 240 may also be a lateral metal oxide semiconductor field effect transistor (lateral MOS). In other embodiments of the present application, the MOS transistors in the main switch tube group 240 are other NMOS transistors. In other embodiments of the present application, the MOS transistors in the main switch tube group 240 are PMOS transistors.

With continued reference to fig. 22, in the present embodiment, the detection switch unit 250 includes one detection switch Guan Guanzu 280, and in other embodiments of the present application, the detection switch unit 250 may further include a plurality of detection switch tube groups 280. In the present embodiment, the detection switch tube group 280 includes a first detection connection terminal 251, a second detection connection terminal 252, and a detection control terminal 253. The first detection connection 251 is electrically connected to the first main connection 211 (in fig. 22) or the second main connection 212, and the second detection connection 252 is electrically connected to the first reference output VMS.

In this embodiment, since the main switch tube group 240 and the detecting switch tube group 280 are both located on the same chip, i.e. on the same silicon wafer, they are all manufactured by the same process. The main switch tube group 240 and the detection switch tube group 280 include MOS transistors of the same type.

In addition, in other embodiments of the present application, the detection switch tube set 280 is preferably identical to the main switch tube set 240, that is, the detection switch tube set 280 also includes a charge body diode and a discharge body diode, so that the detection switch tube set 280 and the main switch tube set 240 are disposed on a chip, which is easier to be implemented in terms of process, simple to manufacture and low in cost. In the present embodiment, the detection switch tube group 280 is preferably switched on or off along with the main switch tube group 240.

Referring to the first to sixth embodiments, the present embodiment can also realize detection of current abnormality when the battery 310 is charged and/or the battery 310 is discharged, through simple modification by those skilled in the art.

Eighth embodiment

Fig. 25 is a schematic view of a battery assembly according to an eighth embodiment of the present application, please refer to fig. 25, wherein the embodiment is similar to the seventh embodiment, and the same parts as the seventh embodiment are not repeated.

Referring to fig. 25, in the present embodiment, the battery protection module 100 further includes a first reference output terminal VMS and a second reference output terminal VMP, a first detection connection terminal 251 of the detection switch tube set 280 is electrically connected to the second reference output terminal VMP, a second detection connection terminal 252 is electrically connected to the first reference output terminal VMS, and the present embodiment can also implement detection of abnormal current when the battery 310 is charged and/or the battery 310 is discharged through simple modification by a person skilled in the art with reference to the first to sixth embodiments.

It should be understood that references herein to "a plurality" are to two or more. Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It should be noted that, in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different manner from other embodiments, and identical and similar parts between the embodiments are referred to each other. For the device embodiments, since they are substantially similar to the method embodiments, the description is relatively simple, and reference is made to the description of the method embodiments for relevant points.

The foregoing disclosure is only illustrative of the preferred embodiments of the present application and is not intended to limit the scope of the claims herein, as the equivalent of the claims herein shall be construed to fall within the scope of the claims herein.

Claims

1. A battery protection device for protecting a battery connected to a load, comprising:

2. The battery protection device of claim 1, wherein the battery protection module further comprises a second constant current generation unit, wherein the first constant current generation unit is electrically connected to the first reference output terminal, and the second constant current generation unit is electrically connected to the second reference output terminal;

3. The battery protection device of claim 1, wherein the battery protection module comprises a comparison loop selection unit, the first reference output terminal and the second reference output terminal are respectively electrically connected with the comparison loop selection unit, and wherein the over-current protection unit comprises a charging over-current protection unit and a discharging over-current protection unit;

4. The battery protection device according to claim 3, wherein the comparison circuit selection unit comprises two first switches, two second switches and a charge/discharge comparator, wherein the output end of the first constant current generation unit is respectively electrically connected with the input end of one of the first switches and the input end of one of the second switches, the output end of the first switch is respectively electrically connected with the second reference output end and the charge overcurrent protection unit, the output end of the second switch is respectively electrically connected with the first reference output end and the discharge overcurrent protection unit, the second reference output end is also electrically connected with the input end of the other second switch, the output end of the second switch is grounded, the output end of the first reference output end is also electrically connected with the input end of the other first switch, the output end of the first switch is electrically connected with the current sampling end, the output end of the current sampling end is respectively electrically connected with the charge/discharge overcurrent protection unit and the input end of the charge/discharge comparator, the other input end of the charge/discharge comparator is grounded, and the output end of the charge/discharge comparator is respectively electrically connected with the control ends of the two first switches and the second switches, and when the first switches and the second switches are turned on and off.

5. The battery protection device according to claim 1, wherein the battery protection module further comprises a single polarity conversion unit, one end of the single polarity conversion unit is electrically connected with the current sampling end, the other end of the single polarity conversion unit is electrically connected with the overcurrent protection unit, and the single polarity conversion unit converts the voltage of the current sampling end into a voltage with the same polarity as the voltage of the first reference output end to the overcurrent protection unit when the voltage of the current sampling end is positive or negative;

6. The battery protection device according to any one of claims 1 to 5, wherein the switch control terminal includes a charge control terminal and a discharge control terminal;

7. The battery protection device according to claim 6, wherein the detection switch unit includes a first detection switch tube group and a second detection switch tube group, wherein the first detection switch tube group includes the first detection connection end, a first intermediate connection end, and a first detection control end, and the second detection switch tube group includes the second detection connection end, a second intermediate connection end, and a second detection control end, wherein the first intermediate connection end is electrically connected with the second intermediate connection end, the first intermediate connection end is electrically connected with the first discharge connection end, the second intermediate connection end is electrically connected with the second charge connection end, and the first detection control end and the second detection control end are each electrically connected with a charge control end or a discharge control end, or the first detection control end and the second detection control end are each electrically connected with a charge control end, a discharge control end, or the first detection control end and the second detection control end are each electrically connected with a discharge control end and a charge control end.

8. The battery protection device according to any one of claims 1 to 5, wherein the detection switch unit includes a first detection switch tube group and a second detection switch tube group, wherein the first detection switch tube group includes the first detection connection end, a first intermediate connection end, and a first detection control end, and the second detection switch tube group includes the second detection connection end, a second intermediate connection end, and a second detection control end, wherein the first intermediate connection end is electrically connected to the second intermediate connection end, and the first detection control end and the second detection control end are electrically connected to a charge control end or a discharge control end, or the first detection control end and the second detection control end are electrically connected to a charge control end, a discharge control end, or the first detection control end and the second detection control end are electrically connected to a discharge control end and a charge control end, respectively.

9. The battery protection device according to any one of claims 1 to 5, wherein the detection switch unit includes a detection switch Guan Guanzu, and the detection switch tube group includes the first detection connection terminal, the second detection connection terminal, and a detection control terminal electrically connected to a discharge control terminal or a charge control terminal.

10. The battery protection device according to any one of claims 1 to 5, wherein,

11. The battery protection device according to claim 10, wherein the bias unit includes a discharging sub-switch and a charging sub-switch, one end of the discharging sub-switch is electrically connected to the second main connection terminal, the other end of the discharging sub-switch is electrically connected to the anode of the charging body diode, one end of the charging sub-switch is electrically connected to the first main connection terminal, the other end of the charging sub-switch is electrically connected to the anode of the charging body diode, and the over-current protection unit is used for controlling on-off of the charging sub-switch and the discharging sub-switch, wherein the discharging sub-switch is turned off when the charging sub-switch is turned on, and the charging sub-switch is turned off when the discharging sub-switch is turned on.

12. The battery protection device according to claim 10, wherein the detection switch unit includes a first detection switch tube group and a second detection switch tube group, wherein the first detection switch tube group includes the first detection connection end, a first intermediate connection end, a first detection control end, and the second detection switch tube group includes the second detection connection end, a second intermediate connection end, a second detection control end, wherein the first intermediate connection end is electrically connected with the second intermediate connection end, and the first intermediate connection end and the second intermediate connection end are electrically connected with an anode of the discharge body diode or an anode of the charge body diode, and the first detection control end and the second detection control end are electrically connected with the switch control end.

13. The battery protection device of any one of claims 1-12, wherein the main switch unit and the detection switch unit each comprise a MOS transistor, the MOS transistor being a trench metal oxide semiconductor or a lateral metal oxide semiconductor.

14. A battery assembly, comprising:

a battery;

the battery protection device of any one of claims 1-13, wherein the first power terminal and the second power terminal of the battery protection device are electrically connected to a battery, respectively.

15. A terminal, comprising:

a load;

the battery assembly of claim 14;