A protection control circuit, protection control device and electronic equipment

Abstract

The utility model discloses a protection control circuit, protection control device and electronic equipment, protection control circuit includes: signal conversion circuit, switch control circuit and protection circuit, signal conversion circuit is connected with external control circuit, is used for receiving the system control signal of external control circuit transmission, and carries out rectifier filter conversion to system control signal, generates switch control signal, switch control circuit is connected with signal conversion circuit, is used for receiving switch control signal, and generates switch protection signal according to switch control signal, protection circuit is connected with switch control circuit, and switch protection signal is used for controlling the working condition of protection circuit. Through signal conversion circuit to the processing of access signal, can avoid the false triggering problem, promotes the security and reliability of protection control circuit. The protection control circuit simple structure, builds conveniently, and the cost is low, and it is convenient to promote.

Description

Technical Field

[0001] This utility model relates to the field of battery management system technology, specifically to a protection control circuit, protection control device, and electronic equipment. Background Technology

[0002] As a core component ensuring the safe operation of batteries, the Battery Management System (BMS) undertakes key functions such as battery status monitoring, equalization control, thermal management, and overcurrent / short-circuit protection. Among these, overcurrent and short-circuit protection are core safety requirements of the BMS, and its response speed and reliability directly determine the safety of the battery system under extreme operating conditions. Traditional BMSs mostly use mechanical fuses or electronic fuses as overcurrent protection devices, but these solutions have drawbacks such as non-recoverable one-time melting, low melting accuracy, and lack of active control. In recent years, three-terminal fuses (TTFs) have gradually become a research hotspot for BMS overcurrent protection due to their controllable melting capability.

[0003] Currently, in battery management systems, three-terminal fuses are mainly controlled by AFE (Active Factor Equipment), secondary protection ICs, or MCUs. AFE control schemes typically require the AFE itself to have fuse control functionality, allowing a single pin to output a drive level to control the fuse's melting. This places high demands on AFE selection and is cumbersome to control. Secondary protection IC control schemes often only output a high level to blow the fuse when the cell voltage is severely overvoltage; this is a purely hardware-based solution, uncontrollable, and has a single trigger condition. MCU control schemes often involve the MCU controlling the AFE via communication to blow the fuse, or adding an NMOS drive circuit where the MCU indirectly controls the fuse's melting by controlling the NMOS's switching on and off. This approach is costly, prone to false triggering, and its reliability needs improvement. Utility Model Content

[0004] This invention provides a protection control circuit to solve the problems of false triggering and low reliability in the prior art.

[0005] This utility model is achieved through the following technical solution: In a first aspect, the first embodiment of this utility model provides a protection control circuit, comprising: a signal conversion circuit, a switch control circuit, and a protection circuit; wherein, The signal conversion circuit is connected to an external control circuit and is used to receive system control signals sent by the external control circuit, and to rectify, filter and transform the system control signals to generate switch control signals. The switch control circuit is connected to the signal conversion circuit and is used to receive the switch control signal and generate a switch protection signal based on the switch control signal. The protection circuit is connected to the switch control circuit, and the switch protection signal is used to control the working state of the protection circuit.

[0006] Furthermore, the signal conversion circuit includes a rectifier unit, the input of which is connected to the output of an external control circuit, for rectifying the input system control signal to obtain a rectified system control signal.

[0007] Furthermore, the signal conversion circuit includes a filtering unit, the input of which is connected to the output of the rectifier unit, for filtering the rectified system control signal to obtain a switching control signal.

[0008] Furthermore, the filtering unit includes a third capacitor, a fourth capacitor, and a fifth capacitor, and the rectifier unit includes a first diode, a second diode, and a third diode. One end of the third capacitor is connected to the signal output terminal of an external control circuit, and the other end of the third capacitor is connected to the cathode of the first diode and the anode of the second diode. The anode of the first diode is connected to one end of the fourth capacitor and then grounded. The cathode of the second diode is connected to the other end of the fourth capacitor and the anode of the third diode. The cathode of the third diode is connected to one end of the fifth capacitor and one end of a pull-down resistor and then input to a switch control circuit. The other end of the fifth capacitor is connected to the other end of the pull-down resistor and then grounded.

[0009] Furthermore, the switch control circuit includes a switch control unit and a protection unit. The input terminal of the switch control unit is connected to the output terminal of the signal conversion circuit to receive switch control signals. The output terminal of the switch control unit is connected to the input terminal of the protection unit, and the output terminal of the protection unit is connected to the control terminal of the protection circuit to generate switch protection signals.

[0010] Further, the switch control unit includes a third resistor, a fourth resistor, a second capacitor, a transistor, a second resistor, and a PMOS transistor. One end of the third resistor is connected to the negative terminal of the third diode. The other end of the third resistor is connected to one end of the fourth resistor, one end of the second capacitor, and the base of the transistor. The other end of the fourth resistor, the other end of the second capacitor, and the emitter of the transistor are connected to the negative terminal of the battery. The collector of the transistor is connected to one end of the second resistor. The other end of the second resistor is connected to the protection unit and the gate of the PMOS transistor. The source of the PMOS transistor is connected to the control terminal of the protection circuit, and the drain of the PMOS transistor is connected to the positive terminal of the battery. Further, the protection unit includes a first resistor, a first capacitor, and a Zener diode. One end of the first resistor, one end of the first capacitor, and the positive terminal of the Zener diode are connected to the other end of the second resistor and the gate of the PMOS transistor. The other end of the second resistor, the other end of the first capacitor, and the negative terminal of the Zener diode are connected to the source of the PMOS transistor and the control terminal of the protection circuit. Further, the protection circuit uses a three-terminal fuse.

[0011] Secondly, another embodiment of the present invention provides a protection control device applied to a battery pack. The protection control device is disposed within the battery pack and includes the protection control circuit described in the above embodiments.

[0012] Thirdly, another embodiment of the present invention provides an electronic device including the protection and control device described in the above embodiments.

[0013] Compared with the prior art, this utility model has the following advantages and beneficial effects: This utility model provides a protection control circuit that uses a signal conversion circuit to rectify, filter, and transform the incoming system control signal to generate a switch control signal. The switch control circuit then generates a switch protection signal based on this signal, which controls the operating state of the protection circuit. By processing the incoming signal through the signal conversion circuit, false triggering problems can be avoided, improving the safety and reliability of the protection control circuit. This protection control circuit has a simple structure, is easy to build, has low cost, and is easy to promote.

[0014] The protection control device and electronic device provided by this utility model are based on the same inventive concept as the protection control circuit and have the same beneficial effects. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 A structural block diagram of a protection control circuit provided in an embodiment of this utility model; Figure 2 A specific circuit diagram of a protection control circuit provided for an embodiment of this utility model. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0017] Please see Figure 1-2 This utility model provides a protection control circuit, comprising: a signal conversion circuit, a switch control circuit, and a protection circuit. The signal conversion circuit is connected to an external control circuit and receives system control signals sent by the external control circuit, rectifying and filtering the system control signals to generate a switch control signal. The switch control circuit is connected to the signal conversion circuit and receives the switch control signal, generating a switch protection signal based on the switch control signal. The protection circuit is connected to the switch control circuit, and the switch protection signal is used to control the operating state of the protection circuit. In this embodiment, the external control circuit uses an MCU. In this embodiment, the protection circuit uses a three-terminal fuse, which can be either WPF45A9K-2P or D6SE02-45. The PMOS transistor can be either AO3401A or AO3415A. The signal conversion circuit performs AC-to-DC conversion and DC-to-AC isolation processing on the received system control signal, ensuring that only AC signals of a certain frequency and amplitude can pass through. This avoids false triggering problems caused by external control circuit failures or line interference, improving the safety and reliability of the entire protection control circuit control process. The signal conversion circuit includes a rectifier unit and a filter unit. The input of the rectifier unit is connected to the output of the external control circuit to rectify the input system control signal to obtain the rectified system control signal. The input of the filter unit is connected to the output of the rectifier unit to filter the rectified system control signal to obtain the switch control signal. A pull-down resistor is also provided after the filter unit to clamp the switch control signal to a low level. The filtering unit includes a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5. The rectifier unit includes a first diode D1, a second diode D2, and a third diode D3. One end of the third capacitor C3 is connected to the signal output terminal of the external control circuit. The other end of the third capacitor C3 is connected to the cathode of the first diode D1 and the anode of the second diode D2. The anode of the first diode D1 is connected to one end of the fourth capacitor C4 and then grounded. The cathode of the second diode D2 is connected to the other end of the fourth capacitor C4 and the anode of the third diode D3. The cathode of the third diode D3 is connected to one end of the fifth capacitor C5 and one end of the pull-down resistor R5 and then input to the switch control circuit. The other end of the fifth capacitor C5 is connected to the other end of the pull-down resistor R5 and then grounded. Diodes D1, D2, and D3 act as unidirectional conductors and level clamps, ensuring unidirectional transmission of the signal input to the external control circuit and preventing reverse breakdown. Capacitors C3, C4, and C5 act as filters. The enable signal MCU-FUSE-EN from the external control circuit is filtered by the third capacitor C3, then unidirectionally turned on by the first diode D1, filtered by the fourth capacitor C4, then unidirectionally turned on by the second diode D2, then unidirectionally turned on by the third diode D3, and finally filtered by the fifth capacitor C5. The signal then passes through a pull-down resistor, which can stabilize the level when there is no enable signal from the external control circuit. Only AC signals of a certain frequency and amplitude can pass through, avoiding false triggering problems caused by external control circuit crashes or line interference, and greatly improving the safety and reliability of the entire protection control circuit.

[0018] The switch control circuit includes a switch control unit and a protection unit. The input terminal of the switch control unit is connected to the output terminal of the signal conversion circuit to receive switch control signals. The output terminal of the switch control unit is connected to the input terminal of the protection unit, and the output terminal of the protection unit is connected to the control terminal of the protection circuit to generate switch protection signals.

[0019] The switch control unit includes a third resistor R3, a fourth resistor R4, a second capacitor C2, a transistor Q2, a second resistor R2, and a PMOS transistor Q1. One end of the third resistor R3 is connected to the negative terminal of the third diode D3. The other end of the third resistor R3 is connected to one end of the fourth resistor R4, one end of the second capacitor C2, and the base of the transistor Q2. The other end of the fourth resistor R4, the other end of the second capacitor C2, and the emitter of the transistor Q2 are connected to the negative terminal of the battery. The collector of the transistor Q2 is connected to one end of the second resistor R2. The other end of the second resistor R2 is connected to the protection circuit module and the gate of the PMOS transistor. The source of the PMOS transistor Q1 is connected to the control terminal of the three-terminal fuse, and the drain of the PMOS transistor Q1 is connected to the positive terminal of the battery. The transistor Q2 is used to control the gate voltage of the PMOS transistor Q1. When the FUSE-HIN input signal of the external control circuit turns on the transistor Q2, it will pull down the gate potential of the PMOS transistor Q1, thus controlling the switching on and off of the PMOS transistor Q1. Zener diode ZD1 is used to stabilize the gate voltage of PMOS transistor Q1 to prevent damage from overvoltage. The first resistor R1 and the first capacitor C1 form an RC network for filtering, soft start-up, and suppressing sudden gate voltage changes. PMOS transistor Q1 controls the melting of the control terminal of the three-terminal fuse, and its gate is controlled by transistor Q2 to determine whether the TP1-TP2 path is open.

[0020] The protection unit includes a first resistor R1, a first capacitor C1, and a Zener diode ZD1. One end of the first resistor R1, one end of the first capacitor C1, and the positive terminal of the Zener diode ZD1 are connected to the other end of a second resistor R2 and the gate of the PMOS transistor, respectively. The other end of the second resistor R2, the other end of the first capacitor C1, and the negative terminal of the Zener diode ZD1 are connected to the source of the PMOS transistor Q1 and the control terminal of the three-terminal fuse F1, respectively. The protection unit uses the positive terminal of the battery as the source voltage input of the PMOS transistor. When the three-terminal fuse F1 needs to be blown, only the gate voltage of the PMOS transistor Q1 needs to be pulled low. This eliminates the need for an additional MOS driver circuit, greatly reducing material and development costs, and also making the overall circuit simpler and easier to build.

[0021] The working principle of the protection control circuit provided in this embodiment is as follows: The MCU-FUSE-EN terminal of the rectifier unit is connected to the I / O port with timer of the external control circuit. When the I / O port of the external control circuit outputs a square wave / PWM, the FUSE-HIN terminal of the filter unit is at a high level. When the I / O port of the external control circuit outputs a constant high / constant low level, the FUSE-HIN terminal of the filter unit is at a low level. Because a signal conversion circuit is set between the MCU-FUSE-EN terminal and the FUSE-HIN terminal, the signal conversion circuit allows AC signals of a certain frequency and amplitude to pass through, avoiding false triggering problems caused by external control circuit crashes, line interference, etc., and greatly improving the safety and reliability of the protection control circuit. When the FUSE-HIN terminal is at a high level, transistor Q2 is turned on, the level at TP3 is pulled low, thereby turning on PMOS transistor Q1, and the level at TP6 is pulled low to the battery B- voltage, causing the three-terminal fuse F1 to be triggered and blown. Test points (TP1-TP5) are used for circuit debugging and can measure the voltage of each node (such as the battery B+ voltage at TP1, the Q1 gate voltage at TP3, etc.), to help troubleshoot and verify circuit logic.

[0022] This utility model provides a protection control circuit that uses a signal conversion circuit to rectify, filter, and transform the incoming system control signal to generate a switch control signal. The switch control circuit then generates a switch protection signal based on this signal, which controls the operating state of the protection circuit. By processing the incoming signal through the signal conversion circuit, false triggering problems can be avoided, improving the safety and reliability of the protection control circuit. This protection control circuit has a simple structure, is easy to build, has low cost, and is easy to promote.

[0023] Another embodiment of the present invention provides a protection control device applied to a battery pack. The protection control device is disposed inside the battery pack and includes the protection control circuit described in the first embodiment.

[0024] Another embodiment of the present invention provides an electronic device including the protection and control device described in the first embodiment.

[0025] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A protection control circuit, characterized in that, include: Signal conversion circuit, switch control circuit, and protection circuit; among which, The signal conversion circuit is connected to an external control circuit and is used to receive system control signals sent by the external control circuit, and to rectify, filter and transform the system control signals to generate switch control signals. The switch control circuit is connected to the signal conversion circuit and is used to receive the switch control signal and generate a switch protection signal based on the switch control signal. The protection circuit is connected to the switch control circuit, and the switch protection signal is used to control the working state of the protection circuit. The signal conversion circuit includes a rectifier unit, the input of which is connected to the output of an external control circuit, and is used to rectify the input system control signal to obtain a rectified system control signal. The signal conversion circuit also includes a filtering unit, the input of which is connected to the output of the rectifier unit, for filtering the rectified system control signal to obtain a switching control signal.

2. The protection control circuit according to claim 1, characterized in that, The filtering unit includes a third capacitor, a fourth capacitor, and a fifth capacitor. The rectifier unit includes a first diode, a second diode, and a third diode. One end of the third capacitor is connected to the signal output terminal of an external control circuit. The other end of the third capacitor is connected to the cathode of the first diode and the anode of the second diode. The anode of the first diode is connected to one end of the fourth capacitor and then grounded. The cathode of the second diode is connected to the other end of the fourth capacitor and the anode of the third diode. The cathode of the third diode is connected to one end of the fifth capacitor and one end of a pull-down resistor and then input to a switch control circuit. The other end of the fifth capacitor is connected to the other end of the pull-down resistor and then grounded.

3. The protection control circuit according to claim 2, characterized in that, The switch control circuit includes a switch control unit and a protection unit. The input terminal of the switch control unit is connected to the output terminal of the signal conversion circuit to receive switch control signals. The output terminal of the switch control unit is connected to the input terminal of the protection unit. The output terminal of the protection unit is connected to the control terminal of the protection circuit to generate switch protection signals.

4. The protection control circuit according to claim 3, characterized in that, The switch control unit includes a third resistor, a fourth resistor, a second capacitor, a transistor, a second resistor, and a PMOS transistor. One end of the third resistor is connected to the negative terminal of the third diode. The other end of the third resistor is connected to one end of the fourth resistor, one end of the second capacitor, and the base of the transistor. The other end of the fourth resistor, the other end of the second capacitor, and the emitter of the transistor are connected and then connected to the negative terminal of the battery. The collector of the transistor is connected to one end of the second resistor. The other end of the second resistor is connected to the protection unit and the gate of the PMOS transistor. The source of the PMOS transistor is connected to the control terminal of the protection circuit, and the drain of the PMOS transistor is connected to the positive terminal of the battery.

5. The protection control circuit according to claim 4, characterized in that, The protection unit includes a first resistor, a first capacitor, and a Zener diode. One end of the first resistor, one end of the first capacitor, and the positive terminal of the Zener diode are connected to the other end of the second resistor and the gate of the PMOS transistor, respectively. The other end of the second resistor, the other end of the first capacitor, and the negative terminal of the Zener diode are connected to the source of the PMOS transistor and the control terminal of the protection circuit, respectively.

6. The protection control circuit according to claim 1, characterized in that, The protection circuit uses a three-terminal fuse.

7. A protection and control device, characterized in that, The protection control device is located within a battery pack and includes a protection control circuit as described in any one of claims 1 to 6.

8. An electronic device, characterized in that, Includes the protection and control device as described in claim 7.

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