CN117013495A - Overcurrent protection circuit, related power adapter and electronic equipment - Google Patents
Overcurrent protection circuit, related power adapter and electronic equipment Download PDFInfo
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- CN117013495A CN117013495A CN202211007976.2A CN202211007976A CN117013495A CN 117013495 A CN117013495 A CN 117013495A CN 202211007976 A CN202211007976 A CN 202211007976A CN 117013495 A CN117013495 A CN 117013495A
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- 238000005070 sampling Methods 0.000 claims abstract description 35
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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- Power Engineering (AREA)
- Emergency Protection Circuit Devices (AREA)
- Dc-Dc Converters (AREA)
Abstract
The embodiment of the application provides an overcurrent protection circuit, a related power adapter and electronic equipment, wherein a primary control chip in the power adapter is connected with a secondary protocol chip in an isolated manner; the primary control chip comprises a main control circuit, the power circuit controls the primary control circuit through the main control circuit, the secondary protocol chip comprises an overcurrent protection circuit, and the overcurrent protection circuit comprises a sampling sub-circuit, a control sub-circuit, a comparison sub-circuit, an anti-shake sub-circuit and a protection sub-circuit. The application collects secondary optocoupler current through the sampling sub-circuit to generate detection signals, the control sub-circuit collects secondary output voltage and primary input voltage to generate detection signal threshold values, the comparison sub-circuit compares the detection signals with the detection signal threshold values, the anti-shake sub-circuit carries out anti-shake detection on comparison results, the protection sub-circuit generates first protection signals according to the comparison results of the anti-shake detection, and the secondary protocol chip realizes overcurrent protection according to the first protection signals.
Description
Technical Field
The application belongs to the technical field of circuit protection, and particularly relates to an overcurrent protection circuit, a related power adapter and electronic equipment.
Background
At present, the flyback converter in the existing high-power adapter is most widely applied in the adapter at present because of primary/secondary isolation, simple topology and mature technology. For the high-power adapter, the secondary protocol chip samples output current through a secondary current sampling resistor and triggers corresponding protection when the output current is abnormal. However, when the secondary chip current sampling circuit fails, the output current only reaches the current protection point of the primary control chip to trigger protection, but the output current protection point of the high input voltage and the low output voltage is obviously higher than the rated output current, which can lead to the failure of timely protection when the system is abnormal, and damage to equipment even danger when serious.
In the current stage, one common method is to detect the switching frequency of the secondary synchronous rectifier tube, and when the switching frequency is reduced to a certain threshold value and the voltage at two ends of the current sampling resistor is lower, the system considers that the current sampling circuit is faulty and outputs overcurrent to perform corresponding protection. However, in the prior art, when the primary enters the CCM mode, the switching frequency is a certain value, so that the frequency of the secondary synchronous rectifier is also a constant value, and at this time, the overcurrent cannot be detected by the method.
Disclosure of Invention
The embodiment of the application provides an overcurrent protection circuit, a related power adapter and an electronic device, which can realize overcurrent protection when the power adapter is in a CRM (critical conduction mode) mode and a CCM (continuous conduction mode) mode.
In a first aspect, an embodiment of the present application provides a power adapter, including a power circuit, a primary control chip, a secondary protocol chip, and an external compensation circuit, where the primary control chip is connected to the secondary protocol chip in an isolated manner by the external compensation circuit, the power circuit is connected to the primary control chip and the external compensation circuit, and the external compensation circuit is connected to the secondary protocol chip; the primary control chip comprises a main control circuit, the main control circuit controls the power circuit to output voltage, the secondary protocol chip comprises an overcurrent protection circuit, and the overcurrent protection circuit comprises a sampling sub-circuit, a control sub-circuit, a comparison sub-circuit, an anti-shake sub-circuit and a protection sub-circuit;
the sampling sub-circuit is used for collecting the secondary optocoupler current output by the external compensation circuit and generating a detection signal according to the secondary optocoupler current;
the control sub-circuit is used for collecting a secondary output voltage and a primary input voltage of the power circuit and generating a detection signal threshold according to the secondary output voltage and the primary input voltage;
and the comparison sub-circuit is used for comparing the detection signal with the detection signal threshold value to obtain a comparison result.
The anti-shake sub-circuit is used for carrying out anti-shake detection on the comparison result;
the protection sub-circuit is used for generating a first protection signal or a second protection signal according to a comparison result of the anti-shake detection, and sending the first protection signal or the second protection signal to a main control unit of a secondary protocol chip, wherein the first protection signal is used for indicating the secondary protocol chip to carry out overcurrent protection.
In a second aspect, an embodiment of the present application provides an overcurrent protection circuit, which is applied to a power adapter, where the power adapter includes a power circuit, a primary control chip, a secondary protocol chip and an external compensation circuit, the primary control chip is isolated from the secondary protocol chip by the external compensation circuit, the power circuit is connected to the primary control chip and the external compensation circuit, and the external compensation circuit is connected to the secondary protocol chip; the primary control chip comprises a main control circuit, the power circuit controls the primary control chip through the main control circuit, and the secondary protocol chip comprises an overcurrent protection circuit;
the overcurrent protection circuit comprises a sampling sub-circuit, a control sub-circuit, a comparison sub-circuit, an anti-shake sub-circuit and a protection sub-circuit;
the sampling sub-circuit is used for collecting the secondary optocoupler current output by the external compensation circuit and generating a detection signal according to the secondary optocoupler current;
the control sub-circuit is used for collecting a secondary output voltage and a primary input voltage of the power circuit and generating a detection signal threshold according to the secondary output voltage and the primary input voltage;
and the comparison sub-circuit is used for comparing the detection signal with the detection signal threshold value to obtain a comparison result.
The anti-shake sub-circuit is used for carrying out anti-shake detection on the comparison result;
the protection sub-circuit is used for generating a first protection signal or a second protection signal according to a comparison result of the anti-shake detection, and sending the first protection signal or the second protection signal to a main control unit of a secondary protocol chip, wherein the first protection signal is used for indicating the secondary protocol chip to carry out overcurrent protection.
In a third aspect, an embodiment of the present application provides an electronic device, including the power adapter according to the first aspect or the overcurrent protection circuit according to the second aspect.
It can be seen that, in the embodiment of the present application, the secondary optocoupler current is collected by the sampling sub-circuit to generate the detection signal, the control sub-circuit collects the secondary output voltage and the primary input voltage to generate the detection signal threshold, the comparison sub-circuit compares the detection signal with the detection signal threshold to obtain a comparison result, the anti-shake sub-circuit performs anti-shake detection on the comparison result, the protection sub-circuit generates the first protection signal according to the comparison result passing the anti-shake detection, and sends the first protection signal to the main control unit of the secondary protocol chip, and the secondary protocol chip realizes overcurrent protection according to the first protection signal. Thus, the power adapter can realize overcurrent protection by detecting the current flowing through the secondary optocoupler in the CRM and CCM modes.
Drawings
In order to more clearly illustrate the embodiments of the 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, it being obvious that the drawings in the following description are only some embodiments of the 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 structural diagram of an overcurrent protection circuit according to an embodiment of the present application;
fig. 2 is a circuit diagram of an overcurrent protection circuit according to an embodiment of the present application;
FIG. 3 is a schematic diagram of a power adapter according to an embodiment of the present application;
fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
Detailed Description
In order that those skilled in the art will better understand the present application, a technical solution in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
The terms first, second and the like in the description and in the claims and in the above-described figures are used for distinguishing between different objects and not necessarily for describing a sequential or chronological order. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may include other steps or elements not listed or inherent to such process, method, system, article, or apparatus.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.
The embodiment of the application provides an overcurrent protection circuit, so that the overcurrent protection can be realized in both a CCM mode and a CRM mode of a power adapter, and the system architecture related to the embodiment of the application is introduced below.
Referring to fig. 1, the present application provides an overcurrent protection circuit 31, which is applied to a power adapter, the power adapter further comprises a power circuit 10, a primary control chip 20, a secondary protocol chip 30 and an external compensation circuit 40, the primary control chip 20 is isolated from the secondary protocol chip 30 by the external compensation circuit 40, the power circuit 10 is connected with the primary control chip 20 and the external compensation circuit 40, and the external compensation circuit 40 is connected with the secondary protocol chip 30; the primary control chip 20 comprises a main control circuit 21, the main control circuit 21 controls the power circuit 10 to output voltage, and the secondary protocol chip 30 comprises an overcurrent protection circuit 31;
the overcurrent protection circuit 31 includes a sampling sub-circuit 310, a control sub-circuit 320, a comparison sub-circuit 330, an anti-shake sub-circuit 340, and a protection sub-circuit 350;
the sampling sub-circuit 310 is configured to collect a secondary optocoupler current IF of the external compensation circuit 40, and generate a detection signal according to the secondary optocoupler current IF;
the control sub-circuit 320 is configured to collect a secondary output voltage Vout and a primary input voltage Vbulk, and generate a detection signal threshold according to the secondary output voltage Vout and the primary input voltage Vbulk;
the comparing sub-circuit 330 is configured to compare the detection signal with the detection signal threshold value to obtain a comparison result.
The anti-shake sub-circuit 340 is configured to perform anti-shake detection on the comparison result;
the protection sub-circuit 350 is configured to generate a first protection signal or a second protection signal according to a comparison result of the anti-shake detection, and send the first protection signal or the second protection signal to the main control unit of the secondary protocol chip 30, where the first protection signal is used to instruct the secondary protocol chip 30 to perform overcurrent protection.
The specific structure of the overcurrent protection circuit 31 is not limited to the form of the sampling sub-circuit 310, the control sub-circuit 320, the comparison sub-circuit 330, the anti-shake sub-circuit 340, and the protection sub-circuit 350. The sampling sub-circuit 310, the control sub-circuit 320, the comparing sub-circuit 330, the anti-shake sub-circuit 340 and the protection sub-circuit 350 may have other existing circuit structures, and only the functions to be implemented in the present embodiment need to be implemented.
In particular, in this embodiment, the sampling sub-circuit 310 is used to collect the secondary optocoupler current IF to generate a detection signal, the control sub-circuit 320 is used to collect the secondary output voltage Vout and the primary input voltage Vbulk to generate a detection signal threshold, the comparing sub-circuit 330 is used to compare the detection signal with the detection signal threshold to obtain a comparison result, the anti-shake sub-circuit 340 is used to perform anti-shake detection on the comparison result, the protection sub-circuit 350 is used to generate a first protection signal according to the comparison result passing the anti-shake detection, and send the first protection signal to the main control unit of the secondary protocol chip 30, and the secondary protocol chip 30 implements over-current protection according to the first protection signal. Thus, the power adapter can realize overcurrent protection by detecting the current flowing through the secondary optocoupler OptoB in the CRM and CCM modes.
It can be seen that, in this embodiment, the sampling sub-circuit is used to collect the secondary optocoupler current to generate the detection signal, the control sub-circuit is used to collect the secondary output voltage Vout and the primary input voltage Vbulk to generate the detection signal threshold, the comparison sub-circuit is used to compare the detection signal with the detection signal threshold to obtain a comparison result, the anti-shake sub-circuit is used to perform anti-shake detection on the comparison result, the protection sub-circuit is used to generate the first protection signal according to the comparison result of the anti-shake detection, and send the first protection signal to the main control unit of the secondary protocol chip, and the secondary protocol chip realizes the overcurrent protection according to the first protection signal.
In one possible embodiment, the sampling sub-circuit 310 includes a secondary output feedback control unit 311 and a mirror current unit 312; the secondary output feedback control unit 311 is configured to regulate a secondary optocoupler current IF to obtain the secondary output voltage Vout; the image current unit 312 is configured to generate an image current of the secondary optocoupler current IF, and generate a corresponding detection signal according to the image current and a voltage and a resistance inside a secondary protocol chip.
In a specific implementation, as shown in fig. 2, the output voltage Vout of the power circuit 10 is divided by a certain proportion to obtain the divided voltage Vdiv, and the divided voltage Vdiv and the reference voltage source Vref control the current flowing through the MOS transistor by controlling the output of the operational amplifier, so as to adjust the magnitude of the secondary optocoupler current IF to realize feedback adjustment of the output. The image current unit 312 images the secondary optocoupler current IF, and converts it into the detection signal Vce through a chip internal voltage and a resistor.
It can be seen that in this embodiment, the secondary output current is sampled by sampling the secondary optocoupler current IF, so as to provide a detection signal for subsequent overcurrent judgment.
In one possible embodiment, as shown in fig. 2, the secondary output feedback control unit 311 includes a first MOS transistor Q1, an error amplifier EA, and a reference voltage source Vref, where a gate of the first MOS transistor Q1 is connected to an output end of the error amplifier EA, a drain of the first MOS transistor Q1 is connected to an output end of the secondary OptoB, a source of the first MOS transistor Q1 is connected to the mirror current unit 312, a non-inverting input end of the error amplifier EA is connected to a Vdiv voltage, an inverting input end of the error amplifier EA is connected to an anode of the reference voltage source Vref, and a cathode of the reference voltage source Vref is connected to a signal ground.
In a specific implementation, the voltage Vdiv is obtained by dividing the output voltage Vout by a certain proportion, the error amplifier EA controls the current flowing through the MOS transistor to regulate the secondary optocoupler current IF, the secondary optocoupler current IF reflects the secondary output condition, and the secondary optocoupler current IF is converted into the detection signal Vce in the chip after passing through the mirror current unit 312.
It can be seen that in this embodiment, the sampling of the secondary output current is achieved by sampling the secondary optocoupler current IF, and the sampling current is provided for the subsequent over-current protection.
In one possible embodiment, as shown in fig. 2, the mirror current unit 312 includes a first transistor Q2, a second transistor Q3, and a first resistor R1; the collector of the first triode Q2 is connected with the secondary output feedback control unit, the base of the first triode and the base of the second triode Q3, the collector of the second triode Q3 is connected with one end of the first resistor R1 and the comparison sub-circuit 330, the other end of the first resistor R1 is connected with the internal voltage, and the emitter of the first triode Q2 and the emitter of the second triode Q3 are connected with signal ground.
In a specific implementation, the first transistor Q2 and the second transistor Q3 form a mirror circuit, and currents of two collectors of the first transistor Q2 and the second transistor Q3 are the same (i.e., imos1=imos2). After the first triode receives the detection current, the value of the Imos2 is known, and thus the value of the detection signal Vce can be obtained. And further by comparing with a detection signal threshold to determine whether over-current protection is required.
The specific circuit principles are described separately below.
Fig. 1 is a schematic structural diagram of an overcurrent protection circuit according to an embodiment of the present application, which includes a power circuit 10, a primary control chip 20, a secondary protocol chip 30 and an external compensation circuit 40. The principle of the present application is to detect the output current by detecting the secondary optocoupler current IF, i.e. the current flowing through the MOSFET inside the secondary protocol chip 30, so that the output current threshold can be set to achieve the required overcurrent protection.
The overcurrent protection circuit shown in fig. 2 is taken as an example, but the method of detecting the secondary protocol chip 30 pin current Imos1 and generating the corresponding detection signal Vce is not limited thereto. In this circuit, vout is set by the secondary protocol chip 30, vbulk is obtained by detecting the voltage value v=vout+vbulk/n when the synchronous rectifier Q4 of the power circuit is turned off reversely, and Imos2 is the mirror image of the current Imos1 flowing into the pin of the secondary protocol chip 30, that is, imos1=imos2, so vce=vdd—imos1×r1 can be obtained, where VDD is the voltage inside the secondary protocol chip, and R1 is the resistance inside the secondary protocol chip 30. The control sub-circuit 320 of the secondary protocol chip 30 sets the corresponding detection signal threshold Vth (the method of generating the detection signal Vth is as follows) according to Vout and Vbulk and sends Vce to the "-" terminal of the comparator Comp1, and Vce is sent to the "+" terminal of the comparator Comp1, when the output current Io increases, VCS increases, VFB (i.e., vfb_open in fig. 2) increases, the primary optocoupler current Ice decreases, the secondary optocoupler currents IF decreases, imos1 and Imos2 decrease, and Vce increases. Therefore, when the output current is too large, the output current will cause Imos1 to be too small, vce will exceed the threshold Vth of the detection signal, if the state is not released within a certain period of time, the secondary protocol chip 30 will set the signal of the protection sub-circuit 350 high, then the secondary protocol chip 30 can use the signal alone as current limiting protection or combine with other internal signals to complete the actually required current limiting protection, for example, after the output current threshold is set, when the signal of the protection sub-circuit 350 is high, the output is directly subjected to current limiting protection, or when the signal of the protection sub-circuit 350 is high and the current detected by the secondary chip through the sampling resistor is smaller than the set threshold, the secondary protocol chip 30 determines that the secondary sampling resistor is short-circuited to perform current limiting protection on the output, and the protection measure can also be set according to the requirement, for example, the path power tube Q5 is turned off or the optical coupler is pulled down.
For CRM mode, its output current Io is related to the secondary optocoupler current IF as follows:
for CCM mode, the relationship between the output current Io and the secondary optocoupler current IF is:
therefore, for the CRM or CCM mode, when the system parameter, the input voltage Vbulk and the output voltage Vout are known, the secondary optocoupler current IF-protection corresponding to the output limiting value Io-protection can be obtained according to equation 1 or equation 2, and the Vce-protection obtained under the output limiting value Io-protection is the detection signal threshold Vth because if=imos1=imos2 and vce=vdd-imos2×r1. When the output current Io exceeds the current limit value Io-protection, the detection signal Vce exceeds the detection signal threshold Vth to trigger corresponding overcurrent protection.
Referring to fig. 2 and 3, the present application further provides a power adapter 100, including a power circuit 10, a primary control chip 20, a secondary protocol chip 30 and an external compensation circuit 40, wherein the primary control chip 20 is isolated from the secondary protocol chip 30 by the external compensation circuit 40, the power circuit 10 is connected with the primary control chip 20 and the external compensation circuit 40, and the external compensation circuit 40 is connected with the secondary protocol chip 30; the primary control chip 20 includes a main control circuit 21, the main control circuit controls the power circuit 10 to output voltage, the secondary protocol chip 30 includes an over-current protection circuit 31, and the over-current protection circuit 31 includes a sampling sub-circuit 310, a control sub-circuit 320, a comparison sub-circuit 330, an anti-shake sub-circuit 340 and a protection sub-circuit 350;
the sampling sub-circuit 310 is configured to collect the secondary optocoupler current IF output by the external compensation circuit 40, and generate a detection signal according to the secondary optocoupler current IF;
the control sub-circuit 320 is configured to collect a secondary output voltage Vout and a primary input voltage Vbulk of the power circuit 10, and generate a detection signal threshold according to the secondary output voltage Vout and the primary input voltage Vbulk;
the comparing sub-circuit 330 is configured to compare the detection signal with the detection signal threshold value to obtain a comparison result.
The anti-shake sub-circuit 340 is configured to perform anti-shake detection on the comparison result;
the protection sub-circuit 350 is configured to generate a first protection signal or a second protection signal according to a comparison result of the anti-shake detection, and send the first protection signal or the second protection signal to the main control unit of the secondary protocol chip 30, where the first protection signal is used to instruct the secondary protocol chip 30 to perform overcurrent protection.
The power adapter 100 may be a mobile power adapter 100, or may be a power adapter 100 of an electric vehicle or the like, and the scope of the present application is not limited only as long as the overcurrent protection circuit 31 applied in the present embodiment is the scope of protection.
Further, since the overcurrent protection circuit 31 has been described in detail above, no unique limitation is made again.
It can be seen that, in the embodiment of the present application, the sampling sub-circuit 310 is used to collect the secondary optocoupler current IF to generate the detection signal, the control sub-circuit is used to collect the secondary output voltage Vout and the primary input voltage Vbulk to generate the detection signal threshold, the comparing sub-circuit 330 is used to compare the detection signal with the detection signal threshold to obtain a comparison result, the anti-shake sub-circuit 340 is used to perform anti-shake detection on the comparison result, the protection sub-circuit 350 is used to generate the first protection signal according to the comparison result passing the anti-shake detection, and send the first protection signal to the main control unit of the secondary protocol chip 30, and the secondary protocol chip 30 implements over-current protection according to the first protection signal. This allows for over-current protection by detecting the current IF flowing through the secondary optocoupler OptoB in both CRM and CCM modes of the power adapter 100.
In one possible embodiment, the sampling sub-circuit 310 includes a secondary output feedback control unit 311 and a mirror current unit 312; the secondary output feedback control unit 311 is configured to adjust a secondary optocoupler current IF to obtain the output voltage; the image current unit 312 is configured to generate an image current of the secondary optocoupler current IF, and generate a corresponding detection signal according to the image current and a voltage and a resistance inside a secondary protocol chip.
In one possible embodiment, the secondary output feedback control unit 311 includes a first MOS transistor Q1, an error amplifier EA, and a reference voltage source Vref, where a gate of the first MOS transistor Q1 is connected to an output terminal of the error amplifier EA, a drain of the first MOS transistor Q1 is connected to an output terminal of a secondary optocoupler OptoB in the external compensation circuit 40, a source of the first MOS transistor Q1 is connected to the mirror current unit 312, a non-inverting input terminal of the error amplifier EA is connected to Vdiv voltage, an inverting input terminal of the error amplifier EA is connected to an anode of the reference voltage source Vref, and a cathode of the reference voltage source Vref is connected to signal ground.
In one possible embodiment, the mirror current unit 312 includes a first transistor Q2, a second transistor Q3, and a first resistor R1;
the collector of the first triode Q2 is connected with the secondary output feedback control unit, the base of the first triode and the base of the second triode Q3, the collector of the second triode Q3 is connected with one end of the first resistor R1 and the comparison sub-circuit 330, the other end of the first resistor R1 is connected with the internal voltage, and the emitter of the first triode Q2 and the emitter of the second triode Q3 are connected with signal ground.
In one possible embodiment, the protection mode of the over-current protection includes pulling down the primary-side optocoupler or turning off the path MOS transistor to cut off the power supply loop.
It can be seen that, in this embodiment, the sampling sub-circuit is used to collect the secondary optocoupler current to generate the detection signal, the control sub-circuit is used to collect the secondary output voltage Vout and the primary input voltage Vbulk to generate the detection signal threshold, the comparison sub-circuit is used to compare the detection signal with the detection signal threshold to obtain a comparison result, the anti-shake sub-circuit is used to perform anti-shake detection on the comparison result, the protection sub-circuit is used to generate the first protection signal according to the comparison result of the anti-shake detection, and send the first protection signal to the main control unit of the secondary protocol chip, and the secondary protocol chip realizes the overcurrent protection according to the first protection signal.
Referring to fig. 4, the present application further provides an electronic device 1 including the power adapter or the overcurrent protection circuit as described above. The electronic device 1 may be any device that requires a power adapter or the above-mentioned overcurrent protection circuit, such as a mobile phone, a computer, a television, an electric vehicle, etc., which is not limited uniquely. Since the power adapter and the overcurrent protection circuit have been described in detail above, they will not be described in detail herein.
Although the present application is disclosed above, the present application is not limited thereto. Variations and modifications, including combinations of the different functions and implementation steps, as well as embodiments of the software and hardware, may be readily apparent to those skilled in the art without departing from the spirit and scope of the application.
Claims (10)
1. The power adapter is characterized by comprising a power circuit, a primary control chip, a secondary protocol chip and an external compensation circuit, wherein the primary control chip is connected with the secondary protocol chip in an isolated manner through the external compensation circuit, the power circuit is connected with the primary control chip and the external compensation circuit, and the external compensation circuit is connected with the secondary protocol chip; the primary control chip comprises a main control circuit, and the main control circuit controls the power circuit to output voltage; the secondary protocol chip includes an over-current protection circuit,
wherein,
the overcurrent protection circuit is used for:
collecting a secondary optocoupler current output by the external compensation circuit, and generating a detection signal according to the secondary optocoupler current; collecting a secondary output voltage and a primary input voltage of the power circuit, generating a detection signal threshold according to the secondary output voltage and the primary input voltage, and comparing the detection signal with the detection signal threshold to obtain a comparison result; performing anti-shake detection on the comparison result; and generating a first protection signal or a second protection signal according to a comparison result of the anti-shake detection, and sending the first protection signal or the second protection signal to a main control unit of a secondary protocol chip, wherein the first protection signal is used for indicating the secondary protocol chip to carry out overcurrent protection.
2. The power adapter of claim 1 wherein the adapter is configured to receive a power adapter,
the overcurrent protection circuit comprises a sampling sub-circuit, a control sub-circuit, a comparison sub-circuit, an anti-shake sub-circuit and a protection sub-circuit;
the sampling sub-circuit is used for collecting the secondary optocoupler current output by the external compensation circuit and generating a detection signal according to the secondary optocoupler current;
the control sub-circuit is used for collecting a secondary output voltage and a primary input voltage of the power circuit and generating a detection signal threshold according to the secondary output voltage and the primary input voltage;
the comparison sub-circuit is used for comparing the detection signal with the detection signal threshold value to obtain a comparison result;
the anti-shake sub-circuit is used for carrying out anti-shake detection on the comparison result;
the protection sub-circuit is used for generating a first protection signal or a second protection signal according to a comparison result of the anti-shake detection, and sending the first protection signal or the second protection signal to a main control unit of a secondary protocol chip, wherein the first protection signal is used for indicating the secondary protocol chip to carry out overcurrent protection.
3. The power adapter of claim 2 wherein the sampling sub-circuit comprises a secondary output feedback control unit and a mirrored current unit;
the secondary output feedback control unit is used for adjusting the secondary optocoupler current to obtain the secondary output voltage;
the mirror current unit is used for generating mirror current of the secondary optocoupler current and generating corresponding detection signals according to the mirror current and voltage and resistance inside the secondary protocol chip.
4. A power adapter according to claim 3, wherein the external compensation circuit comprises a secondary optocoupler for outputting a secondary optocoupler current;
the secondary output feedback control unit comprises a first MOS tube, an error amplifier and a reference voltage source, wherein the grid electrode of the first MOS tube is connected with the output end of the error amplifier, the drain electrode of the first MOS tube is connected with the output end of the secondary optocoupler, the source electrode of the first MOS tube is connected with the mirror image current unit, the positive input end of the error amplifier is connected with Vdiv voltage, the reverse input end of the error amplifier is connected with the positive electrode of the reference voltage source, and the negative electrode of the reference voltage source is connected with signal ground.
5. The power adapter of claim 3 wherein the mirrored current unit comprises a first transistor, a second transistor, and a first resistor;
the collector of the first triode is connected with the secondary output feedback control unit, the base of the first triode and the base of the second triode, the collector of the second triode is connected with one end of the first resistor and the comparison sub-circuit, the other end of the first resistor is connected with the internal voltage VDD, and the emitter of the first triode and the emitter of the second triode are connected with signal ground.
6. The overcurrent protection circuit is characterized by being applied to a power adapter, wherein the power adapter comprises a power circuit, a primary control chip, a secondary protocol chip and an external compensation circuit, the primary control chip is connected with the secondary protocol chip in an isolated manner through the external compensation circuit, the power circuit is connected with the primary control chip and the external compensation circuit, and the external compensation circuit is connected with the secondary protocol chip; the primary control chip comprises a main control circuit, the main control circuit controls the power circuit to output voltage, and the secondary protocol chip comprises an overcurrent protection circuit;
wherein,
the overcurrent protection circuit is used for:
collecting a secondary optocoupler current output by the external compensation circuit, and generating a detection signal according to the secondary optocoupler current; collecting a secondary output voltage and a primary input voltage of the power circuit, generating a detection signal threshold according to the secondary output voltage and the primary input voltage, and comparing the detection signal with the detection signal threshold to obtain a comparison result; performing anti-shake detection on the comparison result; and generating a first protection signal or a second protection signal according to a comparison result of the anti-shake detection, and sending the first protection signal or the second protection signal to a main control unit of a secondary protocol chip, wherein the first protection signal is used for indicating the secondary protocol chip to carry out overcurrent protection.
7. The overcurrent protection circuit of claim 6, wherein,
the overcurrent protection circuit comprises a sampling sub-circuit, a control sub-circuit, a comparison sub-circuit, an anti-shake sub-circuit and a protection sub-circuit;
the sampling sub-circuit is used for collecting the secondary optocoupler current output by the external compensation circuit and generating a detection signal according to the secondary optocoupler current
The control sub-circuit is used for collecting a secondary output voltage and a primary input voltage of the power circuit and generating a detection signal threshold according to the secondary output voltage and the primary input voltage;
the comparison sub-circuit is used for comparing the detection signal with the detection signal threshold value to obtain a comparison result;
the anti-shake sub-circuit is used for carrying out anti-shake detection on the comparison result;
the protection sub-circuit is used for generating a first protection signal or a second protection signal according to a comparison result of the anti-shake detection, and sending the first protection signal or the second protection signal to a main control unit of a secondary protocol chip, wherein the first protection signal is used for indicating the secondary protocol chip to carry out overcurrent protection.
8. The overcurrent protection circuit of claim 7, wherein the sampling sub-circuit comprises a secondary output feedback control unit and a mirror current unit;
the secondary output feedback control unit is used for adjusting the secondary optocoupler current to obtain the secondary output voltage;
the mirror current unit is used for generating mirror current of the secondary optocoupler current and generating corresponding detection signals according to the mirror current and voltage and resistance voltage inside the secondary protocol chip.
9. The overcurrent protection circuit of claim 8, wherein the external compensation circuit comprises a secondary optocoupler for outputting a secondary optocoupler current; the secondary output feedback control unit comprises a first MOS tube, an error amplifier and a reference voltage source, wherein the grid electrode of the first MOS tube is connected with the output end of the error amplifier, the drain electrode of the first MOS tube is connected with the output end of the secondary optocoupler, the source electrode of the first MOS tube is connected with the mirror image current unit, the positive input end of the error amplifier is connected with Vdiv voltage, the reverse input end of the error amplifier is connected with the positive electrode of the reference voltage source, and the negative electrode of the reference voltage source is connected with signal ground.
10. An electronic device comprising a power adapter according to any one of claims 1-5 or an over-current protection circuit according to any one of claims 6-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211007976.2A CN117013495A (en) | 2022-04-29 | 2022-04-29 | Overcurrent protection circuit, related power adapter and electronic equipment |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211007976.2A CN117013495A (en) | 2022-04-29 | 2022-04-29 | Overcurrent protection circuit, related power adapter and electronic equipment |
| CN202210464115.0A CN114567155B (en) | 2022-04-29 | 2022-04-29 | Power adapter, overcurrent protection circuit and electronic equipment |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210464115.0A Division CN114567155B (en) | 2022-04-29 | 2022-04-29 | Power adapter, overcurrent protection circuit and electronic equipment |
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| Publication Number | Publication Date |
|---|---|
| CN117013495A true CN117013495A (en) | 2023-11-07 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202210464115.0A Active CN114567155B (en) | 2022-04-29 | 2022-04-29 | Power adapter, overcurrent protection circuit and electronic equipment |
| CN202211007976.2A Pending CN117013495A (en) | 2022-04-29 | 2022-04-29 | Overcurrent protection circuit, related power adapter and electronic equipment |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202210464115.0A Active CN114567155B (en) | 2022-04-29 | 2022-04-29 | Power adapter, overcurrent protection circuit and electronic equipment |
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| Country | Link |
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| CN (2) | CN114567155B (en) |
| WO (1) | WO2023207789A1 (en) |
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| CN114567155B (en) * | 2022-04-29 | 2022-07-08 | 深圳英集芯科技股份有限公司 | Power adapter, overcurrent protection circuit and electronic equipment |
| CN117578359B (en) * | 2024-01-11 | 2024-04-26 | 深圳市新源鑫电器有限公司 | Automatic over-temperature and over-voltage protection device and method for power adapter |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105449807B (en) * | 2014-09-28 | 2018-04-20 | 比亚迪股份有限公司 | Charging system and its secondary control device based on secondary control |
| CN105391305B (en) * | 2015-12-29 | 2017-09-19 | 杭州茂力半导体技术有限公司 | Isolated form switch converters and its secondary control circuit and control method |
| JP7002919B2 (en) * | 2016-12-16 | 2022-01-20 | ローム株式会社 | Insulation synchronous rectification type DC / DC converter, power adapter and electronic equipment, DC / DC converter control method |
| CN209375470U (en) * | 2019-01-21 | 2019-09-10 | 深圳市吉奥科技有限公司 | A kind of balance modulation switch stabilized voltage power supply |
| CN110943619A (en) * | 2019-12-27 | 2020-03-31 | 深圳英集芯科技有限公司 | Sawtooth wave signal control circuit and sawtooth wave generator |
| CN212183410U (en) * | 2020-03-05 | 2020-12-18 | 深圳市创芯微微电子有限公司 | Current compensation circuit, power control chip and power adapter |
| US11404863B2 (en) * | 2020-04-07 | 2022-08-02 | Leadtrend Technology Corporation | Power supplies with limited power protection and relevant control methods |
| CN112134466B (en) * | 2020-09-09 | 2024-07-02 | 深圳市必易微电子股份有限公司 | Primary side control circuit, power converter and control method thereof |
| CN112968425B (en) * | 2021-04-30 | 2023-02-21 | 重庆斯微奇电子技术有限公司 | Secondary short-circuit protection circuit of switching power supply |
| CN114567155B (en) * | 2022-04-29 | 2022-07-08 | 深圳英集芯科技股份有限公司 | Power adapter, overcurrent protection circuit and electronic equipment |
-
2022
- 2022-04-29 CN CN202210464115.0A patent/CN114567155B/en active Active
- 2022-04-29 CN CN202211007976.2A patent/CN117013495A/en active Pending
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| Publication number | Publication date |
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| WO2023207789A1 (en) | 2023-11-02 |
| CN114567155B (en) | 2022-07-08 |
| CN114567155A (en) | 2022-05-31 |
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