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CN-122026551-A - Bypass power supply system of battery protection board

CN122026551ACN 122026551 ACN122026551 ACN 122026551ACN-122026551-A

Abstract

The invention provides a battery protection board bypass power supply system. The system comprises a bypass driving circuit, a bypass power supply circuit, an analog load removing circuit, a protection chip and a turn-off maintaining circuit, wherein the bypass driving circuit is used for continuously providing a driving signal for the bypass power supply circuit after a main loop discharge tube is turned off, the bypass power supply circuit is used for receiving the driving signal provided by the bypass driving circuit and providing a power supply circuit for a first load connected with the bypass power supply circuit after the main loop discharge tube is turned off, the analog load removing circuit is used for providing a load removing signal for the protection chip after the main loop discharge tube is turned off, the protection chip is used for providing a driving voltage again after receiving the load removing signal so that the bypass power supply circuit continuously provides the power supply circuit for the first load, and the turn-off maintaining circuit is used for enabling the main loop discharge tube to keep in a turn-off state when the protection chip provides the driving voltage again. Therefore, when the protection chip finds that the battery works in an abnormal state and the power supply of the main loop is closed, the first load belonging to the small load can be continuously supplied with power.

Inventors

  • HE QIANGZHI

Assignees

  • 华润微电子（重庆）有限公司

Dates

Publication Date
20260512
Application Date
20241107

Claims (13)

  1. 1. The battery protection board bypass power supply system is characterized in that the battery protection board comprises a protection chip electrically connected with a battery, the protection chip turns off a main circuit discharge tube when detecting abnormal power supply of the battery, and the battery protection board bypass power supply system comprises a bypass driving circuit, a bypass power supply circuit, an analog load removing circuit and a turn-off maintaining circuit; the bypass driving circuit is used for receiving the driving voltage provided by the protection chip and providing a driving signal for the bypass power supply circuit when the main loop discharge tube is turned on, and continuously providing the driving signal for the bypass power supply circuit after the main loop discharge tube is turned off; The bypass power supply circuit is used for receiving the driving signal and providing a power supply loop for a first load connected with the bypass power supply circuit after the main loop discharge tube is closed; The analog load removing circuit is used for providing a load removing signal for the protection chip after the main loop discharge tube is turned off, and the protection chip provides the driving voltage again after receiving the load removing signal so that the bypass power supply circuit continues to provide a power supply loop for the first load; the turn-off maintaining circuit is used for enabling the main loop discharge tube to keep a turn-off state when the protection chip provides driving voltage again.
  2. 2. The battery protection board bypass power supply system of claim 1, wherein the battery protection board includes a battery positive interface and a negative output interface, one end of the first load is connected to the battery positive interface, and the other end of the first load is connected to the negative output interface.
  3. 3. The battery protection board bypass power supply system of claim 2 wherein the analog load removal circuit outputs a load removal signal based on a voltage of the negative output interface, and wherein the shutdown maintenance circuit pulls down a gate drive voltage of the main loop discharge tube based on the voltage of the negative output interface.
  4. 4. The battery protection board bypass power supply system according to claim 2, wherein the protection chip includes a driving end from which the driving voltage is outputted, the driving end is connected to an input end of the bypass driving circuit and to a gate of the main circuit discharge tube, the gate of the main circuit discharge tube is further connected to an output end of the shutdown maintenance circuit, and one end of the main circuit discharge tube is connected to the negative electrode output interface and the other end is grounded.
  5. 5. The battery protection board bypass power supply system of claim 2, wherein the first load includes a display screen for displaying at least voltage, charge, temperature and fault information of the battery.
  6. 6. The battery protection board bypass power supply system according to claim 1, wherein the bypass driving circuit includes a fifth resistor for receiving a driving voltage supplied from the protection chip, a second diode for providing a unidirectional conduction path from a driving end of the protection chip to the bypass power supply circuit, a first capacitor for storing charge when the main loop discharge tube is on and discharging when the main loop discharge tube is off, and a sixth resistor for limiting a current of the bypass driving circuit.
  7. 7. The battery protection board bypass power supply system according to claim 6, wherein one end of the fifth resistor is used as an input end of the bypass driving circuit, the other end of the fifth resistor is connected with one end of the second diode, the other end of the second diode is connected with one end of the first capacitor and one end of the sixth resistor, the other end of the first capacitor is grounded, and the other end of the sixth resistor is used as an output end of the bypass driving circuit.
  8. 8. The battery protection plate bypass power supply system as recited in claim 1, wherein the bypass power supply circuit includes a first diode for providing a unidirectional conduction path from a negative output interface of the battery protection plate to ground, a tenth resistor for limiting a current of the bypass power supply circuit, and a bypass discharge tube as a switch of the bypass power supply circuit.
  9. 9. The battery protection board bypass power supply system according to claim 8, wherein one end of the first diode is connected to the negative electrode output interface of the battery protection board and the other end is connected to one end of the tenth resistor, the other end of the tenth resistor is connected to one end of the bypass discharge tube, the other end of the bypass discharge tube is grounded, and the gate of the bypass discharge tube is connected to the output end of the bypass drive circuit.
  10. 10. The battery protection board bypass power supply system according to claim 1, wherein the protection chip includes a first detection terminal, the protection chip determines whether a load connected to the battery is removed by detecting a voltage received by the first detection terminal, the analog load removal circuit includes a first transistor for pulling down the voltage received by the first detection terminal of the protection chip to simulate a state in which the load has been removed, a second capacitor for filtering the first transistor base voltage, a seventh resistor for fixing the base voltage of the first transistor, and an eighth resistor for limiting a current of the first transistor.
  11. 11. The battery protection board bypass power supply system according to claim 10, wherein a collector electrode of the first triode and a negative electrode output interface of the battery protection board are both connected with the first detection end, an emitter electrode of the first triode is grounded, a base electrode of the first triode is connected with one end of the second capacitor, one end of the seventh resistor and one end of the eighth resistor, the other end of the second capacitor and the other end of the seventh resistor are both grounded, and the other end of the eighth resistor is connected with the negative electrode output interface.
  12. 12. The battery protection board bypass power supply system of claim 1, wherein the turn-off maintaining circuit comprises a fourth resistor, an eleventh resistor, a third capacitor and a second triode, wherein the fourth resistor is used for limiting the current of the second triode, the eleventh resistor is used for fixing the base voltage of the second triode, the third capacitor is used for filtering the base voltage of the second triode, and the second triode is used for reducing the grid driving voltage of the main loop discharge tube.
  13. 13. The battery protection board bypass power supply system of claim 12, wherein one end of the fourth resistor receives the voltage of the negative output interface of the battery protection board, the other end of the fourth resistor is connected to one end of the eleventh resistor, one end of the third capacitor and the base of the second triode, the other end of the eleventh resistor, the other end of the third capacitor and the emitter of the second triode are all grounded, and the collector of the second triode is connected to the gate of the main circuit discharge tube.

Description

Bypass power supply system of battery protection board Technical Field The invention relates to the technical field of circuits, in particular to a battery protection board bypass power supply system. Background Fig. 1 is a schematic circuit diagram of a conventional lithium battery application. As shown in fig. 1, in the application of the lithium battery, the lithium battery module includes a lithium battery pack and a lithium battery protection plate 1 electrically connected, and the lithium battery module is electrically connected with an external charger or load through two interfaces of b+ and P-, to accomplish a charging or discharging function. Fig. 2 is a schematic circuit diagram of a conventional discharge application of a lithium battery protection plate. Referring to fig. 2, in the prior art, a lithium battery protection board samples voltage, discharge current and temperature information of each battery of a lithium battery pack through a protection chip 10, the protection chip 10 samples the discharge current through a resistor RS, and the protection chip 10 detects the resistance value of an NTC resistor through a TC port to determine the battery operating temperature. The discharge control driving end D0 of the protection chip 10 controls the on and off of the discharge MOS tube through the second resistor R2, and the detection port VM of the protection chip 10 samples and detects the P-interface voltage VP through the first resistor R1. When the protection chip 10 finds that the battery is under-voltage, over-current or over-temperature, the driving end D0 of the protection chip 10 outputs a low level to control the discharge MOS tube to be closed, and the continuous power supply to the external large current is forbidden. The detection port VM of the protection chip 10 detects the P-interface voltage VP for load detection, when the discharge MOS tube is turned off, the voltage VP is high, which indicates that the load is still connected, and the driving end D0 continuously outputs a low level, and the discharge MOS tube remains in a turned-off state, so as to prevent heavy current discharge when the battery is under-voltage, over-temperature, and over-current. When the VM detects that the voltage VP is low voltage, the load is removed, the driving end D0 of the protection chip 10 outputs a high level to drive the discharge MOS tube to be turned on after the voltage of the battery is recovered, and the battery can supply power again to the outside. However, many lithium batteries are equipped with a display screen for displaying information such as battery voltage, electric quantity, speed, temperature, faults and the like, and when the discharge MOS tube is closed, the display screen loses power and cannot display battery information and fault types. The display screen is used as a load, so that the driving end D0 of the protection chip continuously outputs a low level to maintain the closing of the discharge MOS tube, and therefore, when the protection chip 10 finds that the lithium battery works in an undervoltage, overcurrent or overtemperature state, the display screen cannot obtain power supply and cannot display relevant information for further analysis, and the use is inconvenient. Disclosure of Invention One of the purposes of the invention is to provide a battery protection board bypass power supply system which can supply power for small loads such as a display screen and the like when a protection chip finds that a battery works in an abnormal state and closes the power supply of a main loop. In order to achieve the above object, the present invention provides a battery protection board bypass power supply system. The battery protection board comprises a protection chip electrically connected with a battery, the protection chip is used for switching off a main loop discharge tube when the battery power supply abnormality is detected, the battery protection board bypass power supply system comprises a bypass driving circuit, a bypass power supply circuit, an analog load removing circuit and a switching-off maintaining circuit, the bypass driving circuit is used for receiving driving voltage provided by the protection chip and providing driving signals for the bypass power supply circuit when the main loop discharge tube is switched on and continuing to provide driving signals for the bypass power supply circuit after the main loop discharge tube is switched off, the bypass power supply circuit is used for receiving the driving signals and providing a power supply circuit for a first load connected with the bypass power supply circuit after the main loop discharge tube is switched off, the analog load removing circuit is used for providing load removing signals for the protection chip after the main loop discharge tube is switched off, the protection chip is used for providing the driving voltage again after the load removing signals are received so that the bypass power supply c