CN213637096U

CN213637096U - Lithium battery charging and discharging protection circuit for Bluetooth sound box

Info

Publication number: CN213637096U
Application number: CN202021577458.0U
Authority: CN
Inventors: 廖城林
Original assignee: Shenzhen Sunpin Industrial Co ltd
Current assignee: Shenzhen Sunpin Industrial Co ltd
Priority date: 2020-07-31
Filing date: 2020-07-31
Publication date: 2021-07-06
Anticipated expiration: 2030-07-31

Abstract

The utility model discloses a lithium cell charge-discharge protection circuit for bluetooth speaker, include: lithium cell group, charge management unit and protection unit, lithium cell group is including two lithium cells that establish ties and set up, charge management unit with protection unit all with lithium cell group electric connection, charge management unit includes a management chip that charges, and the model is CHK8108, protection unit includes a protection chip and an MOS chip, the model of protection chip is HY2120, the model of MOS chip is 8205. The utility model discloses an increase the protection circuit unit of constituteing by HY2120 chip all the way again in the charge-discharge management unit of constituteing by the CHK8108 chip for just calculating the CHK8108 circuit failure of way, the safety of battery can also be protected to the protection circuit of back all the way, can effectively increase battery life, reduces the fault rate of circuit, makes the circuit safer.

Description

Lithium battery charging and discharging protection circuit for Bluetooth sound box

Technical Field

The utility model relates to a lithium battery charging technology field especially relates to a lithium battery charge-discharge protection circuit for bluetooth speaker.

Background

In mobile electronic devices such as bluetooth sound boxes, batteries are required to be used for power supply, and the commonly used batteries are lithium batteries. In the lithium battery, the highest charging termination voltage of a single lithium battery is 4.2V, and overcharging cannot be carried out, otherwise, when the lithium battery is scrapped due to too much loss of lithium ions of a positive electrode to charge the lithium battery, a special constant-current and constant-voltage charger is adopted, and after constant-current charging is carried out until the voltage at two ends of the lithium battery is 4.2V, a constant-voltage charging mode is switched to; when the constant voltage charging current drops to 100mA, the charging should be stopped. In the prior art, generally, only one battery charge-discharge module with charge protection is arranged to protect the safety of a battery core, while in practical use, the power supply charge-discharge module is used as a commonly-used element with relatively large power consumption, and the probability of relative damage is quite high, if the circuit protection circuit is realized or damaged, the battery loses protection, and the consequence is unimaginable.

Accordingly, the prior art is deficient and needs improvement.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the not enough of prior art, providing a lithium cell charge-discharge protection circuit for bluetooth speaker.

The technical scheme of the utility model as follows: the utility model provides a lithium cell charge-discharge protection circuit for bluetooth speaker, include: the lithium battery pack comprises two lithium batteries which are arranged in series, the charging management unit and the protection unit are both electrically connected with the lithium battery pack, the charging management unit comprises a charging management chip with the model of CHK8108, the protection unit comprises a protection chip and an MOS chip, the protection chip is HY2120, and the MOS chip is 8205;

the protection chip comprises six pins, a first pin of the protection chip is electrically connected with a sixth pin of the MOS chip, a second pin of the protection chip is electrically connected with a fourth pin of the MOS chip, a third pin of the protection chip is electrically connected with one end of a first resistor and one end of a first capacitor respectively, the other end of the first resistor and the third pin of the MOS chip are both grounded, a fifth pin and a second pin of the MOS chip are electrically connected, the first pin of the MOS chip is electrically connected with the other end of the first capacitor, a BAT-end of the lithium battery pack, one end of a second capacitor and the sixth pin of the protection chip respectively, the fourth pin of the protection chip is electrically connected with the other end of the second capacitor, one end of the third capacitor and one end of the second resistor respectively, the other end of the second resistor is electrically connected with the BM end of the battery pack, and a fifth pin of the protection chip is electrically connected with the other end of the third capacitor and one end of a third resistor respectively, and the other end of the third resistor is electrically connected with a BAT + end of the lithium battery pack.

Furthermore, the charging management chip comprises eight pins, the first pin of the charging management chip is electrically connected with the cathode of the second diode, one end of the fourth resistor, one end of the fourth capacitor and one end of the fifth capacitor respectively, the other end of the fourth capacitor and the other end of the fifth capacitor are both grounded, the anode of the second diode and the other end of the fourth resistor are both electrically connected with the drain of the first MOS transistor, the drain of the first MOS transistor is also electrically connected with one end of the fifth resistor, the anode of the third diode, the anode of the red light emitting diode and the anode of the green light emitting diode, the source of the first MOS transistor is electrically connected with the DC-IN end and one end of the seventh resistor respectively, the other end of the seventh resistor is electrically connected with the gate of the first MOS transistor and one end of the sixth resistor respectively, and the other end of the sixth resistor is electrically connected with the second pin of the charging management chip, the third pin of the charge management chip is electrically connected with one end of an eighth resistor, the other end of the eighth resistor is electrically connected with the cathode of the green light-emitting diode, the fourth pin of the charge management chip is electrically connected with one end of a ninth resistor, the other end of the ninth resistor is electrically connected with the cathode of the red light-emitting diode, the fifth pin of the charge management chip is grounded, the sixth pin of the charge management chip is respectively electrically connected with one end of an eighth capacitor, one end of the ninth capacitor, the BAT + end of the lithium battery pack, one end of a tenth resistor and the drain of a third MOS (metal oxide semiconductor) tube, the other end of the eighth capacitor and the other end of the ninth capacitor are both grounded, the seventh pin of the charge management chip is respectively electrically connected with one end of a seventh capacitor, the other end of the tenth resistor and one end of an inductor, the other end of the seventh capacitor is grounded, and the other end of the inductor is respectively electrically connected with, The drain electrode of the second MOS tube is electrically connected, the anode of the first diode is grounded, the grid electrode of the second MOS tube is electrically connected with the eighth pin of the charging management chip, the source electrode of the second MOS tube is electrically connected with one end of a sixth capacitor, the cathode of the third diode, the source electrode of the third MOS tube and one end of a switch respectively, the other end of the sixth capacitor is grounded, the other end of the switch is electrically connected with the POWER end, and the grid electrode of the third MOS tube is electrically connected with the other end of the fifth resistor.

Further, the switch is a slide switch.

Further, the ninth capacitor is a polar capacitor.

Adopt above-mentioned scheme, the utility model discloses an increase the protection circuit unit of constituteing by HY2120 chip all the way again in the charge-discharge management unit of constituteing by the CHK8108 chip for just calculating the CHK8108 circuit failure of way, the protection circuit of the back all the way can also protect the safety of battery, can effectively increase battery life, reduces the fault rate of circuit, makes the circuit safer.

Drawings

Fig. 1 is a connection frame diagram of the present invention.

Fig. 2 is a circuit diagram of the protection unit of the present invention.

Fig. 3 is a circuit diagram of the charging management unit of the present invention.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1 to fig. 3, in an embodiment, the present invention provides a lithium battery charging/discharging protection circuit for a bluetooth speaker, including: lithium cell group 200, charge management unit 100 and protection unit 300, lithium cell group 200 is including two lithium batteries that establish ties and set up, charge management unit 100 with protection unit 300 all with lithium cell group 200 electric connection, charge management unit 100 includes a charge management chip U3, and the model is CHK8108, charge management unit 100 is used for right the charge-discharge of lithium battery manages. The protection unit 300 comprises a protection chip U1 and a MOS chip U2, the type of the protection chip U1 is HY2120, the type of the MOS chip U2 is 8205, and the protection unit 300 is used for protecting the lithium battery pack 200 after the charging management unit 100 fails.

Specifically, referring to fig. 2, the protection chip U1 includes six pins, a first pin of the protection chip U1 is electrically connected to a sixth pin of the MOS chip U2, a second pin of the protection chip U1 is electrically connected to a fourth pin of the MOS chip U2, a third pin of the protection chip U1 is electrically connected to one end of a first resistor R1 and one end of a first capacitor C1, the other end of the first resistor R1 and a third pin of the MOS chip U2 are both grounded, a fifth pin and a second pin of the MOS chip U2 are electrically connected, a first pin of the MOS chip U2 is electrically connected to the other end of the first capacitor C1, a BAT-end of the lithium battery pack, one end of a second capacitor C2 and a sixth pin of the protection chip U1, and a fourth pin of the protection chip U1 is electrically connected to the other end of the second capacitor C2 and one end of the third capacitor C3, respectively, One end electric connection of second resistance R2, the other end of second resistance R2 with the BM end electric connection of lithium cell group, protection chip U1's fifth pin respectively with the other end of third electric capacity C3, the one end electric connection of third resistance R3, the other end of third resistance R3 with the BAT + end electric connection of lithium cell group.

Referring to fig. 3, the charge management chip U3 includes eight pins, a first pin of the charge management chip U3 is electrically connected to a cathode of a second diode, an end of a fourth resistor R4, an end of a fourth capacitor C4, and an end of a fifth capacitor C5, the other end of the fourth capacitor C4 and the other end of the fifth capacitor C5 are grounded, an anode of the second diode and the other end of the fourth resistor R4 are electrically connected to a drain of the first MOS transistor Q1, a drain of the first MOS transistor Q1 is further electrically connected to an end of the fifth resistor R5, an anode of the third diode, an anode of the red light emitting diode LED _ R, and an anode of the green light emitting diode LED _ G, a source of the first MOS transistor Q1 is electrically connected to a DC-IN end and an end of a seventh resistor R7, and the other end of the seventh resistor R7 is electrically connected to a gate of the first MOS transistor Q1 and an end of the sixth resistor R6, the other end of the sixth resistor R6 is electrically connected to the second pin of the charge management chip U3, the third pin of the charge management chip U3 is electrically connected to one end of an eighth resistor R8, the other end of the eighth resistor R8 is electrically connected to the negative electrode of the green LED _ G, the fourth pin of the charge management chip U3 is electrically connected to one end of a ninth resistor R9, the other end of the ninth resistor R9 is electrically connected to the negative electrode of the red LED _ R, the fifth pin of the charge management chip U3 is grounded, the sixth pin of the charge management chip U3 is electrically connected to one end of an eighth capacitor C8, one end of a ninth capacitor C9, the BAT + end of the lithium battery pack, one end of a tenth resistor R10 and the drain of a third MOS transistor Q3, the other end of the eighth capacitor C8 and the other end of the ninth capacitor C9 are grounded, and the seventh pin of the charge management chip U3 is electrically connected to one end of a seventh capacitor C7 and the seventh capacitor C7, The other end of the tenth resistor R10 is electrically connected to one end of an inductor L1, the other end of the seventh capacitor C7 is grounded, the other end of the inductor L1 is electrically connected to the cathode of the first diode and the drain of the second MOS transistor Q2, respectively, the anode of the first diode is grounded, the gate of the second MOS transistor Q2 is electrically connected to the eighth pin of the charging management chip U3, the source of the second MOS is electrically connected to one end of a sixth capacitor C6, the cathode of the third diode, the source of the third MOS transistor Q3 and one end of a switch, the other end of the sixth capacitor C6 is grounded, the other end of the switch is electrically connected to the POWER terminal, and the gate of the third MOS transistor Q3 is electrically connected to the other end of the fifth resistor R5.

Please refer to fig. 1 to fig. 3 IN combination, IN the operation of the present invention, IN the charging management unit 100, the externally inputted 9V-24V power is inputted through the DC-IN terminal, and respectively reaches the source and gate of the first MOS transistor Q1 and the second pin of the charging management chip U3, the charging management chip U3 internally controls the OVP overvoltage protection arc and the power indication circuit, when the voltage is normal, the first MOS transistor Q1 is turned on, the power is supplied through the first pin of the charging management chip U3, and when the charging management chip U3 normally operates, the voltage of the lithium battery pack is detected through the tenth resistor R10 and fed back to the charging management chip U3. The charging management chip adopts a trickle, constant current and constant voltage three-stage charging mode. Trickle charging is carried out when the voltage of the lithium battery pack is lower than 6V; when the voltage of the lithium battery pack is between 6V and 8.4V, a constant circuit charging mode is adopted, and the voltage of the lithium battery pack continuously rises at the moment; when the voltage of the lithium battery pack is higher than the preset voltage of 8.4V, a constant voltage charging mode is adopted, the charging current starts to continuously decrease, when the charging current decreases to the preset saturated charging current, the red light emitting diode LED _ R is turned off, and the green light emitting diode LED _ G is turned on to indicate that the charging is finished. When power needs to be supplied to the load, whether power is supplied to the load end or not is turned on through the switch SW 1. In the scheme, on the premise of keeping overvoltage, overcurrent, overtemperature and short-circuit protection of the charging management chip U3, a high-precision protection circuit composed of the protection chip U1 is added, and the charging management unit 100 is matched with the NMOS chip U2 with double power for use, so that when the charging management unit 100 fails, the lithium battery pack can be protected, and the battery and the circuit are prevented from being damaged. In the protection unit 300, the first pin of the protection chip U1 is connected to the sixth pin of the MOS chip U1 for detecting a charging voltage. The second pin of the protection chip U1 is connected with the fourth pin of the MOS chip U2 and is used for detecting a discharge voltage. The third pin of the protection chip is grounded through the first resistor R1 and is used for detecting the current of the circuit. When the protection unit 300 is in a working state, the voltage of the battery cell of the lithium battery pack is fed back to the protection chip IC through the second resistor R2 and the third resistor R3, when the three voltages of VDD-VC, VDD-VSS and VC-VSS of the protection chip U1 are all from 2.5V to 4.3V, and the voltage of the third pin is-150 MV- +150MV, the pin 1 and the pin 2 of the protection chip U1 both output high levels, and at this time, both the two NMOS in the MOS chip U2 are in a conducting state, that is, both the two electronic switches are in an on state. At the moment, the negative electrode of the battery cell is directly communicated with the GND end, and the protection plate outputs voltage. When the lithium battery pack discharges through an external load, the voltage of the lithium battery pack is slowly reduced, three voltages of VDD-VC, VDD-VSS and VC-VSS are reduced to 2.3V, and the duration time is longer than 150MS, the first pin of the protection chip U1 is changed into a low level, the NMOS tube in the MOS chip U2 is closed, the BAT-of the lithium battery pack and the GND end of the protection board are in a disconnected state at the moment, namely, a discharging loop of the lithium battery pack is cut off, the lithium battery pack stops discharging, and over-discharge protection is achieved until the lithium battery pack is charged and then returns to a normal state. After the lithium battery pack is charged, when three groups of voltages, namely VDD-VC, VDD-VSS and VC-VSS, are higher than 4.4V and the duration time exceeds 1000ms along with the increase of the charging time, the second pin of the protection IC outputs low level, so that a corresponding NMOS tube in the MOS chip U2 is closed, and at the moment, the BAT of the lithium battery pack and the GND end of the protection board are in a disconnected state, so that a charging loop is disconnected, and overcharge protection is realized.

To sum up, the utility model discloses an increase the protection circuit unit of constituteing by HY2120 chip all the way again in the charge-discharge management unit of constituteing by the CHK8108 chip for just calculating the CHK8108 circuit failure of way, the protection circuit of the back all the way can also protect the safety of battery, can effectively increase battery life, reduces the fault rate of circuit, makes the circuit safer.

The above description is only exemplary of the present invention and should not be construed as limiting the present invention, and any modifications, equivalents and improvements made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. The utility model provides a lithium cell charge-discharge protection circuit for bluetooth speaker which characterized in that includes: the lithium battery pack comprises two lithium batteries which are arranged in series, the charging management unit and the protection unit are both electrically connected with the lithium battery pack, the charging management unit comprises a charging management chip with the model of CHK8108, the protection unit comprises a protection chip and an MOS chip, the protection chip is HY2120, and the MOS chip is 8205;

2. The lithium battery charging and discharging protection circuit for the bluetooth speaker as claimed IN claim 1, wherein the charging management chip comprises eight pins, the first pin of the charging management chip is electrically connected to the cathode of the second diode, one end of the fourth resistor, one end of the fourth capacitor, and one end of the fifth capacitor, respectively, the other end of the fourth capacitor and the other end of the fifth capacitor are both grounded, the anode of the second diode and the other end of the fourth resistor are both electrically connected to the drain of the first MOS transistor, the drain of the first MOS transistor is further electrically connected to one end of the fifth resistor, the anode of the third diode, the anode of the red light emitting diode, and the anode of the green light emitting diode, the source of the first MOS transistor is electrically connected to the DC-IN terminal and one end of the seventh resistor, respectively, and the other end of the seventh resistor is electrically connected to the gate of the first MOS transistor, respectively, A sixth resistor, a charge management chip, a third pin, an eighth resistor, a fifth resistor, a sixth resistor, a charge management chip, a third pin, an eighth resistor, a fifth resistor, a sixth resistor, a ninth capacitor, a BAT + terminal, a tenth resistor, a third MOS drain electrode, a ninth capacitor, a seventh pin, a seventh capacitor, a sixth pin, a ninth resistor, a ninth capacitor, a fifth resistor, a sixth pin, a ninth capacitor, a BAT + terminal, a tenth resistor, a sixth MOS drain electrode, a sixth capacitor, a ninth capacitor, a seventh capacitor, a sixth pin, a sixth resistor, a ninth capacitor, a sixth pin, a sixth capacitor, a sixth, The other end of the tenth resistor is electrically connected with one end of an inductor, the other end of the seventh capacitor is grounded, the other end of the inductor is electrically connected with the negative electrode of the first diode and the drain electrode of the second MOS tube, the positive electrode of the first diode is grounded, the grid electrode of the second MOS tube is electrically connected with the eighth pin of the charging management chip, the source electrode of the second MOS is electrically connected with one end of a sixth capacitor, the negative electrode of the third diode, the source electrode of the third MOS tube and one end of a switch, the other end of the sixth capacitor is grounded, the other end of the switch is electrically connected with a POWER end, and the grid electrode of the third MOS tube is electrically connected with the other end of the fifth resistor.

3. The lithium battery charging and discharging protection circuit for the Bluetooth speaker as claimed in claim 2, wherein the switch is a slide switch.

4. The lithium battery charging and discharging protection circuit for the Bluetooth sound box as recited in claim 2, wherein the ninth capacitor is a polar capacitor.