CN215419644U

CN215419644U - Overcurrent protection circuit of battery and power supply equipment

Info

Publication number: CN215419644U
Application number: CN202121053469.3U
Authority: CN
Inventors: 罗铁; 雷长镇; 王冰; 沈剑; 黄嘉曦
Original assignee: Shenzhen Immotor Technology Co ltd
Current assignee: Shenzhen Immotor Technology Co ltd
Priority date: 2021-05-17
Filing date: 2021-05-17
Publication date: 2022-01-04
Anticipated expiration: 2031-05-17

Abstract

This application is applicable to battery management technical field, provides an overcurrent protection circuit and power supply unit of battery, and wherein, overcurrent protection circuit includes: the current detection module outputs a first control signal when detecting that an overcurrent signal exists in a charge-discharge loop of the battery; the main control module outputs a switch turn-off signal when receiving the first control signal; the first switch control module outputs a first switch signal when the switch turn-off signal is determined to be an effective signal; the second switch control module is used for discharging the voltage of the controlled end of the switch module in the charge-discharge loop when receiving the switch turn-off signal, and for assisting the first switch control module to discharge the voltage of the controlled end of the switch module based on the first switch signal so as to turn off the switch module, so that the overall time for performing overcurrent protection operation on the battery can be shortened, and the possibility that the battery is damaged is reduced.

Description

Overcurrent protection circuit of battery and power supply equipment

Technical Field

The application belongs to the technical field of battery management, and particularly relates to an overcurrent protection circuit of a battery and power supply equipment.

Background

A Battery Management System (BMS) generally includes an overcurrent protection circuit for performing overcurrent protection on a battery, and the overcurrent protection circuit turns off a switching tube disposed in a charge and discharge circuit of the battery when detecting that an overcurrent signal exists in the charge and discharge circuit of the battery, so as to cut off the charge and discharge circuit of the battery and prevent huge energy generated by the overcurrent signal from damaging the battery.

However, when the current overcurrent protection circuit detects an overcurrent signal, the switch control module in the overcurrent protection circuit needs to judge the authenticity of the overcurrent signal, and the switch tube in the charge and discharge circuit is turned off after the overcurrent signal does exist in the circuit, that is, the current overcurrent protection circuit needs a long time from the detection of the overcurrent signal to the start of turning off the switch tube in the charge and discharge circuit, and the energy generated by the overcurrent signal in the time easily causes the battery damage. Therefore, the existing overcurrent protection circuit has the technical problems that the response time is long when the overcurrent protection operation is carried out on the battery, and the battery is easily damaged.

SUMMERY OF THE UTILITY MODEL

In view of this, embodiments of the present application provide an overcurrent protection circuit for a battery and a power supply device, so as to solve the technical problem that the existing overcurrent protection circuit for a battery has a long response time when performing overcurrent protection operation on the battery, which easily causes damage to the battery.

In a first aspect, an embodiment of the present application provides an overcurrent protection circuit for a battery, including a switch module disposed in a charge-discharge loop of the battery, the overcurrent protection circuit further includes:

the current detection module is arranged in the charge and discharge loop and used for detecting a current signal in the charge and discharge loop when the battery is charged and discharged and outputting a first control signal when an overcurrent signal is detected in the charge and discharge loop;

the main control module is connected with the current detection module and used for outputting a switch turn-off signal when receiving the first control signal;

the first switch control module is connected with the main control module and used for outputting a first switch signal when the switch turn-off signal is received and the switch turn-off signal is determined to be an effective signal;

the second switch control module is connected with the main control module, the first switch control module and the switch module, and is used for discharging the voltage of the controlled end of the switch module when the switch turn-off signal is received, and assisting the first switch control module to discharge the voltage of the controlled end of the switch module based on the first switch signal so as to turn off the switch module.

Optionally, the current detection module includes: the device comprises a current acquisition unit and a signal amplification unit;

the current acquisition unit is arranged in the charge and discharge loop and used for acquiring current signals in the charge and discharge loop when the battery is charged and discharged, converting the current signals into corresponding voltage signals and sending the voltage signals to the signal amplification unit;

the signal amplification unit is connected with the current acquisition unit and used for amplifying the voltage signal, determining that the overcurrent signal exists in the charge-discharge loop when the voltage value of the amplified voltage signal is greater than a second voltage threshold value, and outputting the first control signal.

Optionally, the second switch control module includes: the switch auxiliary control unit and the switch rapid turn-off unit;

the switch rapid turn-off unit is connected with the main control module and the switch module and used for discharging the voltage of the controlled end of the switch module when receiving the switch turn-off signal so as to turn off the switch module;

the switch auxiliary control unit is connected with the main control module, the first switch control module and the switch module, and is used for assisting the first switch control module to discharge the voltage of the controlled end of the switch module based on the first switch signal so as to turn off the switch module.

Optionally, the current collecting unit includes: the circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor, a first diode, a second diode, a fifth resistor and a sixth resistor;

a first end of the first resistor, a first end of the second resistor, a first end of the third resistor, a first end of the fourth resistor, a first end of the first capacitor, a cathode of the first diode, a first end of the third capacitor, and a first end of the fifth resistor are connected in common to serve as a first detection end of the current collection unit, a second end of the first resistor, a second end of the second resistor, a first end of the second capacitor, a cathode of the second diode, a second end of the third capacitor, and a first end of the sixth resistor are connected in common to serve as a second detection end of the current collection unit, a second end of the third resistor, a second end of the fourth resistor, a second end of the first capacitor, a second end of the second capacitor, an anode of the first diode, and an anode of the second diode are all grounded, the second end of the fifth resistor is a first output end of the current acquisition unit, and the second end of the sixth resistor is a second output end of the current acquisition unit.

Optionally, the signal amplifying unit includes: a seventh resistor, an eighth resistor, a ninth resistor, a fourth capacitor, a fifth capacitor and an operational amplifier chip;

a first operational amplifier positive input pin of the operational amplifier chip and a first end of the seventh resistor are commonly connected as a first input end of the signal amplification unit, a second end of the seventh resistor is grounded, a first operational amplifier negative input pin of the operational amplifier chip and a first end of the eighth resistor are commonly connected as a second input end of the signal amplification unit, a first operational amplifier output pin of the operational amplifier chip and a second end of the eighth resistor are commonly connected with a second operational amplifier positive input pin of the operational amplifier chip, a power pin of the operational amplifier chip and a first end of the fourth capacitor are commonly connected with a first power supply, a second end of the fourth capacitor is grounded, a second operational amplifier negative input pin of the operational amplifier chip and a first end of the ninth resistor are commonly connected with a second operational amplifier output pin of the operational amplifier chip, a second end of the ninth resistor and a first end of the fifth capacitor are commonly connected as an output end of the signal amplification unit, and the second end of the fifth capacitor and the ground feet of the operational amplifier chip are both grounded.

Optionally, the switch auxiliary control unit includes: a tenth resistor, an eleventh resistor, a first switch tube, a twelfth resistor, a second switch tube, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a third switch tube and a third diode;

a first end of the tenth resistor is a controlled end of the switching auxiliary control unit, a second end of the tenth resistor and a first end of the eleventh resistor are commonly connected to a controlled end of the first switching tube, a first conduction end of the first switching tube, a first end of the thirteenth resistor and a first end of the twelfth resistor are commonly connected to a controlled end of the second switching tube, a second end of the thirteenth resistor is connected to a second power supply, a first conduction end of the second switching tube is connected to a first end of the fourteenth resistor, a second end of the fourteenth resistor and a first end of the fifteenth resistor are commonly connected to a controlled end of the third switching tube, a first conduction end of the third switching tube, a second end of the fifteenth resistor and a cathode of the third diode are commonly connected as an input end of the switching auxiliary control unit, and a second conduction end of the third switching tube and an anode of the third diode are commonly connected as an anode of the switching auxiliary control unit And the output end of the unit, the second end of the eleventh resistor, the second conduction end of the first switch tube, the second end of the twelfth resistor and the second conduction end of the second switch tube are all grounded.

Optionally, the switch rapid turn-off unit includes: a sixteenth resistor, a seventeenth resistor, a sixth capacitor, a fourth switch tube, an eighteenth resistor, a nineteenth resistor, and a twentieth resistor;

the first end of sixteenth resistance is the controlled end of switch fast turn-off unit, the second end of sixteenth resistance, the first end of sixth electric capacity and the first end of seventeenth resistance connect in altogether the controlled end of fourth switch tube, the first end of fourth switch tube the first end of eighteenth resistance the first end of nineteenth resistance reaches the first end of twentieth resistance connects in unison, the second end of eighteenth resistance the second end of nineteenth resistance reaches the second end of twentieth resistance connects in unison as the output of switch fast turn-off unit, the second end of sixth electric capacity the second end of seventeenth resistance and the second end of fourth switch tube all ground connection.

Optionally, the switch module includes: a ninth switch tube, a seventh capacitor, a twenty-eighth resistor, a first voltage regulator tube, a twenty-ninth resistor, a thirty-eighth resistor and a fifth diode;

the controlled end of the ninth switch tube, the first end of the seventh capacitor and the first end of the twenty-eighth resistor are connected in common to serve as the first controlled end of the switch module, the second end of the twenty-eighth resistor, the cathode of the first voltage regulator tube, the first end of the twenty-ninth resistor, the first end of the thirty-fourth resistor and the anode of the fifth diode are connected in common to serve as the second controlled end of the switch module, the first conducting end of the ninth switch tube, the second end of the seventh capacitor, the anode of the first voltage regulator tube and the second end of the twenty-ninth resistor are connected in common to serve as the first conducting end of the switch module, and the second conducting end of the ninth switch tube is the second conducting end of the switch module.

Optionally, the main control module includes a control chip, an input pin of the control chip is an input end of the main control module, and an on-off control pin of the control chip is an output end of the main control module.

In a second aspect, an embodiment of the present application provides a power supply device, which includes a battery and the overcurrent protection circuit of the first aspect, where the overcurrent protection circuit is connected to the battery.

The embodiment of the application provides an overcurrent protection circuit and power supply equipment of a battery, which have the following beneficial effects:

compared with the prior art, the overcurrent protection circuit of the battery provided by the embodiment of the application can directly turn off the switch module when the current detection module detects that the overcurrent signal exists in the charging and discharging loop of the battery, the main control module can directly output the switch turn-off signal when receiving the first control signal, and the second switch control module can directly discharge the voltage of the controlled end of the switch module when receiving the switch turn-off signal, so that the second switch control module can directly turn off the switch module when receiving the switch turn-off signal without waiting for the first switch control module to judge the validity of the switch turn-off signal and then turn off the switch module, thereby shortening the time from the detection of the overcurrent signal existing in the charging and discharging loop to the start of turning off the switch module, namely shortening the response time of the overcurrent protection circuit to the overcurrent protection operation of the battery, this can reduce the likelihood of damage to the battery; in addition, the first switch control module outputs the first switch signal after determining that the switch turn-off signal is the valid signal, and the second switch control module assists the first switch control module to further discharge the voltage of the controlled end of the switch module based on the first switch signal, so that the time required by the switch module from being turned off to being turned off completely can be shortened, and the possibility of damaging the battery is further reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of an overcurrent protection circuit of a battery according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of an overcurrent protection circuit of a battery according to another embodiment of the present application;

fig. 3 is a schematic circuit diagram of an overcurrent protection circuit of a battery according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a power supply device according to an embodiment of the present application.

Detailed Description

In the embodiments of the present application, terms such as "first" and "second" are used to distinguish the same or similar items having substantially the same function and action. For example, the first resistor and the second resistor are only used for distinguishing different resistors, and the sequence order of the resistors is not limited. Those skilled in the art will appreciate that the terms "first," "second," etc. do not denote any order or quantity, nor do the terms "first," "second," etc. denote any order or importance.

It is noted that, in the present application, words such as "exemplary" or "for example" are used to mean exemplary, illustrative, or descriptive. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

In the present application, "at least one" means one or more, "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone, wherein A and B can be singular or plural.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an overcurrent protection circuit of a battery according to an embodiment of the present disclosure. As shown in fig. 1, the overcurrent protection circuit 100 is used to connect a battery 200. For example, the battery 200 may be formed by connecting a plurality of battery cells in series. In the embodiment of the present application, the overcurrent protection circuit 100 includes: the battery charger comprises a current detection module 11, a main control module 12, a first switch control module 13, a second switch control module 14 and a switch module 15 arranged in a charge-discharge loop of the battery 200. Here, the charge/discharge circuit of the battery 200 refers to a circuit from the positive electrode of the battery 200 to the negative electrode of the battery 200 when the battery 200 is charged or discharged.

Specifically, the current detection module 11 is disposed in a charge and discharge loop of the battery 200, and the current detection module 11 is configured to detect a current signal in the charge and discharge loop when the battery 200 is charged and discharged, and output a first control signal to the main control module 12 when detecting that an overcurrent signal exists in the charge and discharge loop.

In practical applications, the current detection module 11 may be disposed between the negative electrode of the battery 200 and the negative charge/discharge port PACK-of the battery 200, and the switch module 15 may be disposed between the positive electrode of the battery 200 and the positive charge/discharge port PACK + of the battery 200. The positive charge and discharge port PACK + and the negative charge and discharge port PACK-of the battery 200 are used to connect a load or a charging device.

In one possible implementation, the current detection module 11 may determine that the over-current signal is detected in the charge and discharge circuit when detecting that the current value of the current signal in the charge and discharge circuit is greater than the first current threshold. The first current threshold may be set according to actual requirements, and is not limited herein.

The first control signal is used for instructing the main control module 12 to output a signal for turning off the switch module 15, so as to turn off the switch module 15, and further cut off the charge and discharge loop of the battery 200. Illustratively, the first control signal may be a high level signal.

Specifically, the main control module 12 is connected to the current detection module 11, and the main control module 12 is configured to output a switch-off signal to the first switch control module 13 and the second switch control module 14 when receiving the first control signal output by the current detection module 11.

The switch-off signal is used to instruct the first switch control module 13 and/or the second switch control module 14 to bleed off the voltage of the controlled terminal of the switch module 15, so as to turn off the switch control module 16. For example, the switch off signal may be a high level signal.

Specifically, the first switch control module 13 is connected to the main control module 12, and the first switch control module 13 is configured to output a first switch signal when receiving a switch-off signal output by the main control module 12 and determining that the switch-off signal is an effective signal.

In a possible implementation manner, the first switch control module 13 may determine that the switch-off signal output by the main control module 12 is an active signal when detecting that the switch-off signal is a high-level signal.

The first switching signal is used to bleed off the voltage at the controlled terminal of the switching module 15. Illustratively, the first switching signal may be a low level signal.

Specifically, the second switch control module 14 is connected to the main control module 12, the first switch control module 13 and the switch module 15, and the second switch control module 14 is configured to discharge the voltage at the controlled end of the switch module 15 when receiving a switch turn-off signal output by the main control module 12, and to discharge the voltage at the controlled end of the switch module 15 based on the first switch signal output by the first switch control module 13 to assist the first switch control module 13 in discharging the voltage at the controlled end of the switch module 15, so as to turn off the switch module 15.

In a possible implementation manner, the second switch control module 14 may discharge the voltage of the controlled terminal of the switch module 15 to the ground, and since the potential of the ground is stable, discharging the voltage of the controlled terminal of the switch module 15 to the ground may enable the switch module 15 not to generate a surge when being turned off, so that the switch module 15 is not turned on secondarily, and the possibility that the battery 200 is damaged when the switch module 15 is turned off is reduced.

In this embodiment of the application, the second switch control module 14 further cuts off a path through which the first switch control module 13 sends a signal to the switch module 15 when receiving the switch off signal output by the main control module 12, and only allows the signal of the switch module 15 to flow to the first switch control module 13, so that when the first switch control module 13 outputs the first switch signal, because the first switch signal is a low level signal, the signal of the switch module 15 can be caused to flow to the first switch control module 13, and the voltage of the controlled terminal of the switch module 15 is released.

As can be seen from the above, the over-current protection circuit for a battery provided in the embodiment of the present application outputs a first control signal to the main control module when the current detection module detects that an over-current signal exists in a charge/discharge circuit of the battery, the main control module directly outputs a switch turn-off signal when receiving the first control signal, and the second switch control module directly discharges a voltage at a controlled terminal of the switch module when receiving the switch turn-off signal, compared with the prior art, the second switch control module in the embodiment of the present application directly turns off the switch module when receiving the switch turn-off signal without performing a turn-off operation on the switch module after waiting for the first switch control module to determine the validity of the switch turn-off signal, thereby shortening a time from detecting that the over-current signal exists in the charge/discharge circuit to starting to turn off the switch module, the response time of the overcurrent protection circuit for overcurrent protection operation on the battery is shortened, so that the possibility of damaging the battery can be reduced; in addition, the first switch control module outputs the first switch signal after determining that the switch turn-off signal is the valid signal, and the second switch control module assists the first switch control module to further discharge the voltage of the controlled end of the switch module based on the first switch signal, so that the time required by the switch module from being turned off to being turned off completely can be shortened, and the possibility of damaging the battery is further reduced.

Referring to fig. 2, fig. 2 is a schematic structural diagram of an overcurrent protection circuit of a battery according to another embodiment of the present application. As shown in fig. 2, compared with the overcurrent protection circuit in the embodiment corresponding to fig. 1, the current detection module 11 in the overcurrent protection circuit 200 provided in the present embodiment includes: a current collection unit 111 and a signal amplification unit 112.

Specifically, the current collecting unit 111 is disposed in a charge and discharge loop of the battery 200, and the current collecting unit 111 is configured to collect a current signal in the charge and discharge loop when the battery 200 is charged and discharged, convert the current signal into a corresponding voltage signal, and send the voltage signal to the signal amplifying unit 112.

The current collecting unit 111 may be disposed between the negative electrode of the battery 200 and the negative charge/discharge port PACK-of the battery 200, for example, the first detecting end of the current collecting unit 111 may be connected to the negative electrode of the battery 200, the second detecting end of the current collecting unit 111 may be connected to the negative charge/discharge port PACK-of the battery 200, and the first output end and the second output end of the current collecting unit 111 are both connected to the signal amplifying unit 112.

Specifically, the signal amplifying unit 112 is connected to the current collecting unit 111 and the main control module 12, and the signal amplifying unit 112 is configured to amplify the voltage signal from the current collecting unit 111, and output a first control signal to the main control module 12 when a voltage value of the amplified voltage signal is greater than a second voltage threshold.

A first input end of the signal amplifying unit 112 may be connected to a first output end of the current collecting unit 111, a second input end of the signal amplifying unit 112 may be connected to a second output end of the current collecting unit 111, and an output end of the signal amplifying unit 112 may be connected to an input end of the main control module 12.

The second voltage threshold may be set according to actual requirements, and is not limited herein.

With continued reference to fig. 2, in yet another embodiment of the present application, the second switch control module 14 includes: a switching assistant control unit 141 and a switching fast turn-off unit 142.

Specifically, the switch fast turn-off unit 142 is connected to the main control module 12 and the switch module 15, and the switch fast turn-off unit 142 is configured to discharge a voltage of the controlled terminal of the switch module 15 when receiving a switch turn-off signal output by the main control module 12, so as to turn off the switch module 15.

The controlled terminal of the switch fast turn-off unit 142 may be connected to the output terminal of the main control module 12, and the output terminal of the switch fast turn-off unit 142 may be connected to the first controlled terminal of the switch module 15.

In one possible implementation, the switching quick-off unit 142 may bleed the voltage of the controlled terminal of the switching module 15 to the ground to reduce the possibility that the battery 200 is damaged when the switching module 15 is turned off.

Specifically, the switch auxiliary control unit 141 is connected to the main control module 12, the first switch control module 13 and the switch module 15, and the switch auxiliary control unit 141 is configured to assist the first switch control module 13 to discharge the voltage of the controlled end of the switch module 15 based on the first switch signal output by the first switch control module 13, so as to turn off the switch module 15.

The controlled terminal of the switch auxiliary control unit 141 may be connected to the output terminal of the main control module 12, the input terminal of the switch fast turn-off unit 142 may be connected to the output terminal of the first switch control module 13, and the output terminal of the switch auxiliary control unit 141 may be connected to the second controlled terminal of the switch module 15.

In addition, the input terminal of the first switch control module 13 may be connected to the output terminal of the main control module 12.

Referring to fig. 3, fig. 3 is a schematic circuit diagram of an over-current protection circuit of a battery according to an embodiment of the present disclosure. For convenience of explanation, only the portions related to the present embodiment are shown. As shown in fig. 3, with respect to the embodiment corresponding to fig. 2, the current collecting unit 111 in this embodiment includes: the circuit comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first diode D1, a second diode D2, a fifth resistor R5 and a sixth resistor R6.

Wherein, the first end of the first resistor R1, the first end of the second resistor R2, the first end of the third resistor R3, the first end of the fourth resistor R4, the first end of the first capacitor C1, the cathode of the first diode D1, the first end of the third capacitor C3 and the first end of the fifth resistor R5 are commonly connected as the first detection end of the current collection unit 111, the second end of the first resistor R1, the second end of the second resistor R2, the first end of the second capacitor C2, the cathode of the second diode D2, the second end of the third capacitor C3 and the first end of the sixth resistor R6 are commonly connected as the second detection end of the current collection unit 111, the second end of the third resistor R3, the second end of the fourth resistor R4, the second end of the first capacitor C1, the first end of the second diode C2, the anode of the first diode D9642 and the anode of the first diode D2 are all connected as the first detection end of the first detection unit 111, the second end of the sixth resistor R6 is the second output end of the current collecting unit 111.

Referring to fig. 3, in another embodiment of the present application, the signal amplifying unit 112 includes: a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a fourth capacitor C4, a fifth capacitor C5 and an operational amplifier chip U1.

Wherein, the first ends of the first operational amplifier positive input pin + INB and the seventh resistor R7 of the operational amplifier chip U1 are commonly connected as the first input end of the signal amplifying unit 112, the second end of the seventh resistor R7 is grounded, the first ends of the first operational amplifier negative input pin-INB and the eighth resistor R8 of the operational amplifier chip U1 are commonly connected as the second input end of the signal amplifying unit 112, the second ends of the first operational amplifier output pin OUTB and the eighth resistor R8 of the operational amplifier chip U1 are commonly connected to the second operational amplifier positive input pin + INA of the operational amplifier chip U1, the power pin VDD of the operational amplifier chip U1 and the first end of the fourth capacitor C4 are commonly connected to the first power VCC1, the second end of the fourth capacitor C4 is grounded, the second end of the second operational amplifier negative input pin-INA and the first end of the ninth resistor R9 of the operational amplifier chip U1 are commonly connected to the second power supply pin VCC1, the second end of the ninth resistor R9 is commonly connected to the second end of the second operational amplifier negative input pin-INA of the operational amplifier chip U1, and the ninth resistor R3985 is commonly connected to the second end of the signal amplifying unit 112, the second end of the fifth capacitor C5 and the ground pin VSS of the operational amplifier chip U1 are both grounded.

In a particular application, the first power supply may be used to provide a power supply signal having a voltage value of VCC 1. Illustratively, VCC1 may be 3.3 volts (V).

Referring to fig. 3, in another embodiment of the present application, the main control module 12 may specifically include a control chip U2. An input pin IN1 of the control chip U2 is an input end of the main control module 12, and an on-off control pin OUT1 of the control chip U2 is an output end of the main control module 12.

Referring to fig. 3, in another embodiment of the present application, the first switch control module 13 may specifically include a battery management chip U3. The input pin IN2 of the battery management chip U3 is the input end of the first switch control module 13, and the output pin OUT2 of the battery management chip U3 is the output end of the first switch control module 13.

The types or models of the control chip U2 and the battery management chip U3 may be set according to actual requirements, and are not limited herein.

Referring to fig. 3, in another embodiment of the present application, the switching auxiliary control unit 141 includes: a tenth resistor R10, an eleventh resistor R11, a first switch tube Q1, a twelfth resistor R12, a second switch tube Q2, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a third switch tube Q3 and a third diode D3.

Wherein, the first end of the tenth resistor R10 is the controlled end of the switch auxiliary control unit 141, the second end of the tenth resistor R10 and the first end of the eleventh resistor R11 are commonly connected to the controlled end of the first switch tube Q1, the first conducting end of the first switch tube Q1, the first end of the thirteenth resistor R13 and the first end of the twelfth resistor R12 are commonly connected to the controlled end of the second switch tube Q2, the second end of the thirteenth resistor R13 is connected to the second power supply, the first conducting end of the second switch tube Q2 is connected to the first end of the fourteenth resistor R14, the second end of the fourteenth resistor R14 and the first end of the fifteenth resistor R15 are commonly connected to the controlled end of the third switch tube Q3, the first conducting end of the third switch tube Q3, the second end of the fifteenth resistor R15 and the cathode of the third diode D3 are commonly connected as the input end of the switch auxiliary control unit 141, the third conducting end of the third switch tube Q3 and the anode 3 are commonly connected to the output end of the switch auxiliary control unit 141, the second terminal of the eleventh resistor R11, the second conducting terminal of the first switch Q1, the second terminal of the twelfth resistor R12 and the second conducting terminal of the second switch Q2 are all grounded.

In a specific application, the first switching tube Q1 may be a first NPN transistor, the second switching tube Q2 may be a second NPN transistor, and the third switching tube Q3 may be a first PNP transistor. The base of the first NPN transistor is the controlled end of the first switching transistor Q1, the collector of the first NPN transistor is the first conducting end of the first switching transistor Q1, and the emitter of the first NPN transistor is the second conducting end of the first switching transistor Q1. The base of the second NPN transistor is the controlled terminal of the second switching transistor Q2, the collector of the second NPN transistor is the first conducting terminal of the second switching transistor Q2, and the emitter of the second NPN transistor is the second conducting terminal of the second switching transistor Q2. The base of the first PNP transistor is the controlled terminal of the third transistor Q3, the collector of the first PNP transistor is the second conducting terminal of the third transistor Q3, and the emitter of the first PNP transistor is the first conducting terminal of the third transistor Q3.

In a particular application, the second power supply may be used to provide a power supply signal having a voltage value of VCC 2. Illustratively, VCC2 may be 5V.

Referring to fig. 3, in another embodiment of the present application, the switching fast turn-off unit 142 includes: a sixteenth resistor R16, a seventeenth resistor R17, a sixth capacitor C6, a fourth switch Q4, an eighteenth resistor R18, a nineteenth resistor R19 and a twentieth resistor R20.

A first end of the sixteenth resistor R16 is a controlled end of the switch fast turn-off unit 142, a second end of the sixteenth resistor R16, a first end of the sixth capacitor C6 and a first end of the seventeenth resistor R17 are commonly connected to a controlled end of the fourth switch tube Q4, a first conducting end of the fourth switch tube Q4, a first end of the eighteenth resistor R18, a first end of the nineteenth resistor R19 and a first end of the twentieth resistor R20 are commonly connected, a second end of the eighteenth resistor R18, a second end of the nineteenth resistor R19 and a second end of the twentieth resistor R20 are commonly connected as an output end of the switch fast turn-off unit 142, and a second end of the sixth capacitor C6, a second end of the seventeenth resistor R17 and a second conducting end of the fourth switch tube Q4 are all grounded.

In a specific application, the fourth switching transistor Q4 may be a third NPN transistor. The base of the third NPN transistor is the controlled end of the fourth switching transistor Q4, the collector of the third NPN transistor is the first conducting end of the fourth switching transistor Q4, and the emitter of the third NPN transistor is the second conducting end of the fourth switching transistor Q4.

Referring to fig. 3, in another embodiment of the present application, the first conducting terminal of the switch module 15 may be connected to the positive charging/discharging port PACK + of the battery 200, and the second conducting terminal of the switch module 15 may be connected to the positive electrode of the battery 200. The switch module 10 may specifically include: a ninth switch tube Q9, a seventh capacitor C7, a twenty-eighth resistor R28, a first voltage regulator tube D6, a twenty-ninth resistor R29, a thirty-third resistor R30, and a fifth diode D5.

The controlled end of the ninth switch tube Q9, the first end of the seventh capacitor C7, and the first end of the twenty-eighth resistor R28 are commonly connected as the first controlled end of the switch module 10, the second end of the twenty-eighth resistor R28, the cathode of the first regulator tube D6, the first end of the twenty-ninth resistor R29, the first end of the thirty-fourth resistor R30, and the anode of the fifth diode D5 are commonly connected, the second end of the thirty-fourth resistor R30 and the cathode of the fifth diode D5 are commonly connected as the second controlled end of the switch module 10, the first conducting end of the ninth switch tube Q9, the second end of the seventh capacitor C7, the anode of the first regulator tube D6, and the second end of the twenty-ninth resistor R29 are commonly connected as the first conducting end of the switch module 10, and the second conducting end of the ninth switch tube Q9 is the second conducting end of the switch module 10.

In a specific application, the ninth switching transistor Q9 may be a first NMOS transistor. The gate of the first NMOS transistor is the controlled end of the ninth switch transistor Q9, the source of the first NMOS transistor is the first conducting end of the ninth switch transistor Q9, and the drain of the first NMOS transistor is the second conducting end of the ninth switch transistor Q9.

The following describes in detail the specific operation principle of the overcurrent protection circuit 100 of the battery according to the embodiment of the present application with reference to fig. 3:

when the battery 200 is charged or discharged, the first resistor R1 and the second resistor R2 convert a current signal in a charge-discharge loop of the battery 200 into a corresponding voltage signal (a voltage value U of the voltage signal is I × R, where I is a current value of the current signal in the charge-discharge loop, and R is a resistance value of the first resistor R1 or the second resistor R2), the voltage signal is filtered by a filter circuit composed of the first capacitor C1, the second capacitor C2, and the third capacitor C3 and then reaches the first operational amplifier positive input pin + INB and the first operational amplifier negative input pin INB of the operational amplifier chip U1, and the first operational amplifier inside the operational amplifier chip U1 amplifies the filtered voltage signal. Since the resistance R of the first resistor R1 or the second resistor R2 and the amplification factor of the first operational amplifier inside the operational amplifier chip U1 are known, the operational amplifier chip U1 can obtain the current value of the current signal in the charge and discharge circuit of the battery 200 by detecting the voltage value of the amplified voltage signal.

When the operational amplifier chip U1 detects that the voltage value of the amplified voltage signal is less than or equal to the second voltage threshold, it indicates that the current value of the current signal IN the charge-discharge circuit is less than or equal to the first current threshold, that is, there is no overcurrent signal IN the charge-discharge circuit, at this time, the operational amplifier chip U1 outputs a low-level signal (i.e., a second control signal) to the second operational amplifier positive input pin + INA of the operational amplifier chip U1 through the first operational amplifier output pin OUTB thereof, and the second operational amplifier inside the operational amplifier chip U1 holds the low-level signal and outputs the low-level signal to the input pin IN1 of the control chip U2 through the second operational amplifier output pin OUTA of the operational amplifier chip U1. When receiving the low level signal output by the operational amplifier chip U1, the control chip U2 outputs a low level signal (i.e., a switch conducting signal) through the on-off control pin OUT1, and on one hand, the low level signal turns off the fourth switching tube Q4 to maintain the level of the gate of the ninth switching tube Q9; on the other hand, the first switch Q1 in the switching auxiliary control unit 141 is turned off, and then the level of the base of the second switch Q2 is raised to turn on the second switch Q2, and when the second switch Q2 is turned on, the voltage of the base of the third switch Q3 is lowered to turn on the third switch Q3. Meanwhile, when the input pin IN2 of the battery management chip U3 receives the low level signal output by the control chip U2, the output pin OUT2 outputs a high level signal, and the high level signal passes through the third switch tube Q3, the thirtieth resistor R30 and the twenty-eighth resistor R28 and then reaches the gate of the ninth switch tube Q9 to turn on the ninth switch tube Q9, so as to turn on the charge-discharge loop of the battery 200, and the battery 200 can be charged or discharged normally.

When the operational amplifier chip U1 detects that the voltage value of the amplified voltage signal is greater than the second voltage threshold, it indicates that the current value of the current signal IN the charge-discharge loop is greater than the first current threshold, that is, there is an overcurrent signal IN the charge-discharge loop, at this time, the operational amplifier chip U1 outputs a high-level signal (i.e., a first control signal) to the second operational amplifier positive input pin + INA of the operational amplifier chip U1 through the first operational amplifier output pin OUTB thereof, and the second operational amplifier inside the operational amplifier chip U1 holds the high-level signal and outputs the high-level signal to the input pin IN1 of the control chip U2 through the second operational amplifier output pin OUTA of the operational amplifier chip U1. When receiving the high level signal output by the operational amplifier chip U1, the control chip U2 outputs a high level signal (i.e., a switch off signal) through the on-off control pin OUT1, and the high level signal turns on the fourth switching tube Q4 in the switch fast-off unit 142, and further pulls the gate of the ninth switching tube Q9 to the ground through the eighteenth resistor R18, so that the voltage of the gate of the ninth switching tube Q9 is quickly released to the ground, and the ninth switching tube Q9 is quickly turned off, thereby cutting off the charge and discharge loop of the battery 200 to stop charging or discharging the battery 200; on the other hand, the high level signal output by the on-off control pin OUT1 of the control chip U2 turns on the first switching tube Q1 in the switching auxiliary control unit 141, and then pulls down the level of the base of the second switching tube Q2 to turn off the second switching tube Q2, and when the second switching tube Q2 is turned off, the base of the third switching tube Q3 is at a high level to turn off the third switching tube Q3, so that the battery management chip U3 cannot output an electrical signal to the gate of the ninth switching tube Q9 through the output pin OUT 2. Meanwhile, the input pin IN2 of the battery management chip U3, when receiving the high level signal output by the control chip U2, will determine the authenticity of the high level signal, and when determining that the high level signal is true, will output a low level signal through the output pin OUT2, and the low level signal may also pull down the voltage of the gate of the ninth switching tube Q9, so that the ninth switching tube Q9 is turned off.

As can be seen from the above description, when an overcurrent signal exists in a charge and discharge circuit of the battery 200, a high level signal (i.e., a turn-off control signal) output by the control chip U2 can directly turn on the fourth switching tube Q4 in the switching fast turn-off unit 142 to pull down the voltage of the gate of the ninth switching tube Q9 to fast turn off the ninth switching tube Q9, so that the time from when the overcurrent protection circuit 100 detects that the overcurrent signal exists in the charge and discharge circuit to when the ninth switching tube Q9 starts to be turned off is shortened, that is, the response time of the overcurrent protection circuit 100 in performing the overcurrent protection operation on the battery 200 is shortened, and thus the possibility that the battery 200 is damaged is reduced. Meanwhile, since the gate of the ninth switching tube Q9 is directly pulled to the ground when the fourth switching tube Q4 is turned on, that is, the overcurrent protection circuit 100 is referenced to the ground when performing overcurrent protection operation on the battery 200, and the potential of the ground is stable, the voltage of the gate of the ninth switching tube Q9 does not fluctuate when being turned off, so that the ninth switching tube Q9 is not turned on for a second time, and the possibility that the battery 200 is damaged is further reduced.

The embodiment of the application also provides power supply equipment. Referring to fig. 4, fig. 4 is a schematic structural diagram of a power supply apparatus according to an embodiment of the present disclosure. The power supply device 40 includes a battery 200 and an overcurrent protection circuit 100 of the battery connected to the battery 200. The detailed structure and beneficial effects of the over-current protection circuit 100 can refer to the related descriptions in the foregoing embodiments, and are not described herein again.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims

1. The utility model provides an overcurrent protection circuit of battery, is including setting up the switch module in the charge-discharge circuit of battery, its characterized in that, overcurrent protection circuit still includes:

2. The overcurrent protection circuit of claim 1, wherein the current detection module comprises: the device comprises a current acquisition unit and a signal amplification unit;

3. The overcurrent protection circuit of claim 1, wherein the second switch control module comprises: the switch auxiliary control unit and the switch rapid turn-off unit;

4. The overcurrent protection circuit of claim 2, wherein the current collection unit comprises: the circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor, a first diode, a second diode, a fifth resistor and a sixth resistor;

5. The overcurrent protection circuit of claim 2, wherein the signal amplification unit comprises: a seventh resistor, an eighth resistor, a ninth resistor, a fourth capacitor, a fifth capacitor and an operational amplifier chip;

6. The overcurrent protection circuit of claim 3, wherein the switching auxiliary control unit comprises: a tenth resistor, an eleventh resistor, a first switch tube, a twelfth resistor, a second switch tube, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a third switch tube and a third diode;

7. The overcurrent protection circuit of claim 3, wherein the switching fast turn-off unit comprises: a sixteenth resistor, a seventeenth resistor, a sixth capacitor, a fourth switch tube, an eighteenth resistor, a nineteenth resistor, and a twentieth resistor;

8. The overcurrent protection circuit of any one of claims 1 to 7, wherein the switch module comprises: a ninth switch tube, a seventh capacitor, a twenty-eighth resistor, a first voltage regulator tube, a twenty-ninth resistor, a thirty-eighth resistor and a fifth diode;

9. The overcurrent protection circuit of any one of claims 1 to 7, wherein the main control module comprises a control chip, an input pin of the control chip is an input end of the main control module, and an on-off control pin of the control chip is an output end of the main control module.

10. A power supply device characterized by comprising a battery and the overcurrent protection circuit as set forth in any one of claims 1 to 9, the overcurrent protection circuit being connected to the battery.