Pulse type driving circuit applied to high side charge-discharge protection of battery pack

Abstract

The application discloses a pulse type driving circuit applied to high-side charge-discharge protection of a battery pack, which comprises a battery pack module, a charging switch tube module, a discharging switch tube module, a charge pump module, a voltage gate, a safety shutdown circuit module and a control logic generation circuit; the battery pack module is connected with the charging switch tube module and the charge pump module; the charge pump module is connected with the voltage gate; the voltage gate is connected with the charging switch tube module, the discharging switch tube module and the safety shutdown circuit module; the charging switch tube module is connected with the discharging switch tube module; the safety shutdown circuit module is connected with the discharging switch tube module; and the control logic generation circuit is connected with the voltage gate and the safety shutdown circuit module. The application can improve the stability and reliability of the charge-discharge process and realize pulse type discharge protection of the discharging switch tube.

Description

Technical Field

[0001] This invention belongs to the field of battery management chip technology, specifically relating to a pulse drive circuit for high-side charge and discharge protection of battery packs. Background Technology

[0002] Battery management chips typically integrate multiple functions such as over-temperature protection, over-voltage protection, over-current protection, and short-circuit protection. The realization of these functions largely depends on the precise control and management of the charging and discharging process of multiple series-connected batteries.

[0003] High-side drive switches, as common power switching devices, are widely used in DC power management, electric vehicles, industrial control systems, and power inverters. They are indispensable core components in many electronic systems, used to regulate load current. Unlike low-side drive switches, the control terminal of a high-side drive switch is directly connected to the positive terminal of the power supply rather than the ground terminal. They are typically constructed using MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) or IGBTs (Insulated-Gate Bipolar Transistors). When a control signal is applied to the control terminal of the switch, the switch closes, allowing current to flow through the load. By adjusting the on and off states of the switch, precise regulation and control of the load current can be achieved.

[0004] Existing research on high-side switch drivers mainly focuses on the following aspects: 1. High-efficiency energy conversion: Designing efficient high-side switch driver circuits by optimizing drive waveforms, reducing switching losses, and shortening turn-on and turn-off times to improve energy conversion efficiency. 2. High-frequency switching technology: Researching how to achieve high-frequency switching operation to reduce the size of inductors and capacitors, thereby improving power density and system response speed. Achieving this goal relies on designing high-side switch drivers with high-speed response capabilities. 3. Integrated design: Exploring the integration of high-side switch drivers with control logic and protection functions onto a single chip to reduce system size, lower costs, and simplify design. 4. Electromagnetic compatibility (EMC) and electromagnetic interference (EMI): Researching how to design high-side switch drivers that suppress electromagnetic interference to ensure that the system does not interfere with surrounding electronic equipment during operation. 5. Fault protection and diagnosis: Researching how to design high-side switch drivers with fault protection and diagnosis functions such as overcurrent, overtemperature, and short circuit to extend system lifespan and enhance reliability. 6. Application of novel semiconductor devices: Research the introduction of novel semiconductor devices such as SiC (silicon carbide) or GaN (gallium nitride) in high-side switch driving to improve efficiency and reduce system size and weight.

[0005] As can be seen from the above, existing research on high-side switch driving mainly focuses on the material structure of the switch itself in high frequency and radio frequency applications. However, it lacks specific solutions for practical problems such as tube burnout during the switching and conduction processes in specific applications. Furthermore, the protection circuits for high-side MOSFETs in the existing technology mainly focus on the protection requirements of large current and large reverse high voltage, while lacking specific solutions for the specific voltage control problem during the switching process. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides a pulse-driven circuit for high-side charge-discharge protection of battery packs.

[0007] The technical problem to be solved by this invention is achieved through the following technical solution:

[0008] This invention provides a pulse-type drive circuit for high-side charge / discharge protection of a battery pack, comprising: a battery pack module, a charging switch module, a discharging switch module, a charge pump module, a voltage selector, a safety shutdown circuit module, and a control logic generation circuit; the battery pack module is connected to the charging switch module and the charge pump module; the charge pump module is connected to the voltage selector; the voltage selector is connected to the charging switch module, the discharging switch module, and the safety shutdown circuit module; the charging switch module is connected to the discharging switch module; and the safety shutdown circuit module is connected to the discharging switch module; the control logic generation circuit is connected to the voltage selector and the safety shutdown circuit module.

[0009] The charging switch transistor CSW in the charging switch transistor module is used to control the on / off state of the charging circuit of the battery pack in the battery pack module; the discharging switch transistor DSW in the discharging switch transistor module is used to control the on / off state of the discharging circuit of the battery pack; the charge pump module is used to boost the input voltage; the control logic generation circuit is used to generate different control signals required by the voltage selector and the safety shutdown circuit module; the voltage selector is used to control the gate voltage of CSW and DSW by controlling the switching state of the charging and discharging path between the input and output, so as to control the on / off state of CSW and DSW; the safety shutdown circuit module is used to control the gate-source voltage of DSW within a preset safety range during the DSW shutdown process.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0011] 1) Compared to current protection technologies for high-side MOSFETs that mainly focus on protecting power switching transistors under short-circuit or overload conditions, the pulse drive circuit proposed in this invention for high-side charge and discharge protection of battery packs can achieve precise control of the gate voltage through a voltage selector, thereby ensuring the stability and reliability of the charge and discharge process.

[0012] 2) To avoid device damage due to excessive gate-source voltage during the turn-off of the discharge switch, the pulse-driven circuit proposed in this invention for high-side charge-discharge protection of battery packs can gradually release the charge of the gate-source capacitor in a pulse manner through the safety turn-off circuit module. This controls the gate-source voltage within a safe range, ensuring the safety and device integrity of the circuit during the turn-off process. It effectively avoids excessive gate-source voltage, ensures the safe turn-off of the discharge switch, and realizes pulse-type discharge protection for the discharge switch, further enhancing the safety and reliability of the entire circuit.

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the circuit structure of a pulse drive circuit for high-side charge and discharge protection of a battery pack, provided by an embodiment of the present invention.

[0015] Figure 2 This is a schematic diagram of a circuit structure of the CSW voltage selector provided in an embodiment of the present invention;

[0016] Figure 3 This is a schematic diagram of a circuit structure of the DSW voltage selector provided in an embodiment of the present invention;

[0017] Figure 4 This is a schematic diagram of a circuit structure of a safety shutdown circuit provided in an embodiment of the present invention;

[0018] Figure 5 This is a schematic diagram of the turn-off process of the discharge switch provided in an embodiment of the present invention;

[0019] Figure 6 This is a schematic diagram of a control logic generation circuit provided in an embodiment of the present invention. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0021] The application background of this invention is the safe control of the charging and discharging switching transistors of multi-channel series batteries, especially the safe turn-off of the discharge transistor near the load side. This is achieved by controlling the discharge path to ensure the gate-source voltage difference of the discharge transistor remains within a normal range. This invention proposes an innovative circuit design that allows for controllable adjustment of the gate-source voltage difference involved in the switch turn-off process. By precisely controlling the gate discharge speed, it avoids the risk of device damage caused by excessively high or rapidly decreasing gate-source voltage. Through optimized discharge paths and control mechanisms, this invention enables the smooth discharge process of the gate-source capacitor, thereby improving circuit reliability while ensuring the safe turn-off of the switch, demonstrating significant innovation and practical value.

[0022] Specifically, this invention proposes a pulse-type drive circuit for high-side charge / discharge protection of battery packs. This pulse-type drive circuit includes: a battery pack module, a charging switch module, a discharging switch module, a charge pump module, a voltage selector, a safety shutdown circuit module, and a control logic generation circuit. The battery pack module is connected to the charging switch module and the charge pump module. The charge pump module is connected to the voltage selector. The voltage selector is connected to the charging switch module, the discharging switch module, and the safety shutdown circuit module. The charging switch module is connected to the discharging switch module, and the safety shutdown circuit module is connected to the discharging switch module. The control logic generation circuit is connected to the voltage selector and the safety shutdown circuit module. The charging switch (CSW) in the charging switch module controls the on / off state of the charging circuit of the battery pack in the battery pack module. The discharging switch (CSW) in the discharging switch module controls the on / off state of the discharging circuit of the battery pack. The charge pump module is used to boost the input voltage. The control logic generation circuit generates different control signals required by the voltage selector and the safety shutdown circuit module. The voltage selector controls the gate voltages of the CSW and DSW by controlling the switching state of the charging and discharging paths between the input and output, thereby controlling the on / off state of the CSW and DSW. The safety shutdown circuit module controls the gate-source voltage of the DSW to remain within a preset safe range during the DSW shutdown process.

[0023] For example, Figure 1 This is a schematic diagram of a pulse-type drive circuit for high-side charge / discharge protection of a battery pack, provided by an embodiment of the present invention. Figure 1 As shown, the battery pack module includes: battery pack T, diode D1, capacitor C1, and resistor R. sense The charge pump module includes: a charge pump circuit and capacitor C2. The charging switch module includes: CSW, resistor R1, and Zener diode D5. The discharging switch module includes: DSW, resistor R2, resistor R3, and Zener diode D6. The safety shutdown circuit module includes: a safety shutdown circuit and resistor R... 16The negative terminal of transistor T is grounded (GND), and the positive terminal of T is connected to the anode of D1. The cathode of D1 is connected to one end of C1, one end of C2, and the input terminal BAT of the charge pump circuit. The other end of C1 is grounded, and the other end of C2 is connected to the output terminal CP of the charge pump circuit. The charge pump circuit is used to boost the input voltage and output the boosted voltage. BAT is also the input terminal of the charge pump module, and CP is also the output terminal of the charge pump module. The source of CSW is connected to one end of R1 and the anode of D5. The other end of R1 and the cathode of D5 are both connected to the gate of CSW. The gate of CSW is the CHG terminal. The drain of CSW is connected to the drain of DSW. The gate of DSW is connected to one end of R3. The other end of R3 serves as the DSG terminal, which is the first terminal of the discharge switch module. The end of R3 connected to the gate of DSW is also connected to one end of R2 and the cathode of D6. The other end of R2 and the anode of D6 are both connected to the source of DSW. 16 One end is connected to the safety shutdown circuit, and the other end is connected to the source of the DSW. The safety shutdown circuit is connected to the DSG terminal and the voltage selector, which is also connected to the BAT terminal, CP terminal, CHG terminal, and DSG terminal. Furthermore, Figure 1 R in L This indicates the load resistor that can be connected to the pulse drive circuit proposed in this invention, through the connection of load resistor R. L It can simulate the discharge current I DSW Conduct testing. Figure 1 V in chg This indicates that the pulse drive circuit proposed in this invention can be connected to a charger, via a charger V. chg It can simulate the charging current I CHG Perform the test. SENSE Used in current detection, by measuring the resistance R SENSE By sampling the voltage at both ends, current information can be obtained. When the battery pack experiences overcurrent or short circuit, it is necessary to be able to accurately detect such abnormal conditions in order to protect the battery pack.

[0024] like Figure 1As shown, the voltages at the BAT and CP terminals serve as inputs to the voltage selector. CSW and DSW control the on / off states of the charging and discharging circuits of battery pack T, respectively. D3 and D4 are the body diodes of CSW and DSW, respectively. When one of the CSW and DSW switches is on while the other is off, current flows through the body diode of the off switch, ensuring that the current path controlled by the on switch is not affected. Resistors R1 and R2 are connected across the gate and source of CSW and DSW, respectively, providing a discharge path for the gate-source capacitance when the switch is off. Zener diodes D5 and D6 are connected between the gate and source of CSW and DSW, providing overvoltage protection when the gate-source voltage exceeds the safe range. The presence of D5 prevents CSW from being damaged due to excessive gate-source voltage. R1 is a pull-down resistor at the gate of CSW, ensuring that the charge on its gate-source capacitance is completely discharged when CSW needs to be turned off. The same applies to R2 and D6 connected on the DSW side. R3 is a current-limiting resistor. When DSW is turned off, R3 limits the discharge current of the gate capacitor, thereby controlling the turn-off speed of DSW. The switching of CSW and DSW is essentially achieved through the charging and discharging of the gate-source capacitor. The voltage selector controls the switching state of the charging and discharging path between the input and output by the control signal generated by the control logic generation circuit. Specifically, when CSW is turned off, the current path between ports CHG and BAT is open, and the current path between CHG and CP is closed. The gate-source capacitor discharges to BAT, so that the gate and source voltages eventually approach the BAT voltage to ensure that CSW is turned off. When CSW is turned on, the current path between ports CHG and BAT is closed, while the current path between CHG and CP is open. At this time, capacitor C2 charges the gate-source capacitor, so that the gate-source voltage difference reaches CP-BAT and exceeds the CSW's turn-on threshold voltage to achieve turn-on. Similarly, when the DSW is on, the gate voltage is the same as the CP port voltage; when the DSW's gate voltage is the same as the BAT port voltage, the current flowing through it is relatively small, which is suitable for the chip's sleep mode. In this case, the charging and discharging current mainly flows through the DSW's body diode. Figure 1 As shown, the voltage at the LD port (i.e., the voltage at the positive terminal of the load) is supplied through resistor R. 16 Connected to PACK+, R 16 This allows the voltage at the LD port to follow the voltage at the PACK+ terminal. When the DSW is turned off, the gate voltage DSG needs to be discharged to the LD, and the gate-source voltage difference is close to zero. Under heavy load conditions, the load impedance R of the battery pack... LWhen the load is relatively small, the DSW is turned off, and the gate-source capacitor discharges rapidly through the load path. The voltage at PACK+ drops quickly to the voltage at VSS. However, under light load conditions, the load impedance RL of the battery pack is relatively large, and the discharge current of the gate-source capacitor through the load path is small. Therefore, by setting a safety shutdown circuit, an additional discharge path can be provided to accelerate the discharge process and shorten the response time of the DSW shutdown. At the same time, it ensures that the gate-source voltage is maintained within a safe range during the DSW discharge, avoiding excessive gate-source negative voltage damage to the DSW due to a slow voltage drop at PACK+ and a rapid drop at the gate-source voltage under light load. In this invention, the voltage selector and the safety shutdown circuit are collectively referred to as the gate-end drive circuit. Its operating sequence logic is as follows: the charge pump circuit first boosts the output voltage to the desired value, and then the gate-end drive circuit starts. This can improve the system stability of the pulse drive circuit provided by this invention.

[0025] In this invention, the voltage selector includes a CSW voltage selector and a DSW voltage selector, wherein the CSW voltage selector is used to control the CSW, and the DSW voltage selector is used to control the DSW. The CSW voltage selector is connected to the output terminal of the charge pump module (i.e., Figure 1 The CP terminal and the input terminal (i.e.) Figure 1 The BAT terminal in the middle), the gate of CSW (i.e. Figure 1 The CSW voltage selector is connected to the CHG terminal of the DSW module and the control logic generation circuit. The CSW voltage selector controls the gate voltage of the CSW by controlling the switching state of the charging and discharging path between the input and output, thereby controlling the on / off state of the CSW. The DSW voltage selector is connected to the output terminal of the charge pump module (i.e., the...). Figure 1 The CP terminal and the input terminal (i.e.) Figure 1 The BAT terminal in the middle), the first terminal of the discharge switch module (i.e. Figure 1 The first terminal of the DSG and safety shutdown circuit module (i.e. Figure 1 The DSW voltage selector is connected to the LD terminal and the control logic generation circuit. It is used to control the gate voltage of the DSW by controlling the switching state of the charging and discharging path between the input and output, thereby controlling the on / off state of the DSW.

[0026] For example, Figure 2 This is a circuit diagram of a CSW voltage selector. (Example) Figure 2 As shown, the CSW voltage selector includes: a PMOS switch M P1 ~M P12 NMOS switch M N1 ~M N5 Resistance R 01 R 02 Current source A0. M P1 The drain is connected to the CP terminal, M P1 The gate and MP2 gate connection, M P1 The source and M P2 The source connection, M P2 The drain of the CSW is simultaneously connected to the gate and M. P4 The drain connection, M P4 The source and M P3 The source connection, M P4 The gate and M P3 gate connection, M P3 The drain is connected to the BAT terminal, M P5 The source and M P4 The source connection, M P5 After the drain and gate are connected to M P6 The source connection, M P6 After the drain and gate are connected to M P7 The source connection, M P7 After the drain and gate are connected to M P8 The source connection, M P8 After the drain and gate are connected, they are simultaneously connected with M. P5 The source and M P4 gate connection, R 02 Connected to M P5 The source and M P8 Between the drain and the M electrode; P9 The source and M P1 The source connection, M P9 After the drain and gate are connected to M P10 The source connection, M P10 After the drain and gate are connected to M P11 The source connection, M P11 After the drain and gate are connected to M P12 The source connection, M P12 After the drain and gate are connected, they are simultaneously connected with M. P9 The source and M P2 gate connection, R 01 Connected to M P9 The source and M P12 Between the drain and the M electrode; N1 The drain and M P12 The drain connection, M N1 The gate is used to receive the control signal oen_chg, M N1 The source and M N4 The drain connection, M N4 The gate of M is simultaneously N3 Gate and drain, M N5 gate connection, M N4 The source and M N3 The source, M N5The sources of M are all connected to the VSS terminal. N3 After the drain and gate are connected, they are also connected to one end of A0, and the other end of A0 is connected to VDD. N5 The drain and M N2 The source connection, M N2 The drain and M P8 The drain connection, M N2 The gate is used to receive the control signal cen_chg, which is inverse of the control signal oen_chg. Figure 2 In the middle, M P1 With M P2 M P3 With M P4 All power switch pairs are configured in reverse series, specifically in that they are source-connected switch types, M P5 ~M P12 For the switching transistor M P1 ~M P4 It serves as a high-current protection device. M N4 and M N5 The current I of mirror MN3 bias1 The control signals oen_chg and cen_chg are inverted signals, and control the high-voltage switching transistor M respectively. N1 and M N2 M N1 and M N2 Control M separately N4 and M N5 The current path of the mirror image. When oen_chg is high, M N1 On, M N2 When the circuit is turned off, current flows through resistor R. 01 A pressure difference is generated, and the high-pressure switching tube M P1 and M P2 When the charge pump circuit is high, the path between the output terminals CP and CHG is open, allowing the gate-source capacitance of the charge pump circuit (CSW) to charge. The gate voltage of CSW rises to the voltage at the CP port, and CSW turns on. When cen_chg is high, M... N2 On, M N1 When the circuit is turned off, current flows through resistor R. 02 A pressure difference is generated, and the high-pressure switching tube M P3 M P4 When the circuit is turned on, the path between the output terminal CP and the BAT terminal of the charge pump circuit is opened, and the gate-source capacitor of the CSW can discharge through this path. The gate voltage of the CSW drops to the voltage at the BAT port, and the CSW turns off.

[0027] For example, Figure 3 This is a schematic diagram of the circuit structure of a DSW voltage selector. For example... Figure 3As shown, the DSW voltage selector includes: a PMOS switch M 1 P1 ~M 1 P15 NMOS switch M 1 N1 ~M 1 N5 Resistance R 1 01 R 1 02 R 1 03 and current source A1. M 1 P1 The source is connected to the CP terminal, M 1 P1 The drain and M 1 P2 The drain connection, M 1 P2 The source is connected to the DSG terminal, M 1 P3 The drain is connected to the BAT terminal, M 1 P3 The source and M 1 P4 The source connection, M 1 P4 The drain and M 1 P2 The drain connection, M 1 P4 The gate and M 1 P3 gate connection, M 1 P5 The source and M 1 P4 The source connection, M 1 P5 After the gate and drain are connected to M 1 P6 The source connection, M 1 P6 After the gate and drain are connected to M 1 P7 The source connection, M 1 P7 After the gate and drain are connected to M 1 P8 The source connection, M 1 P8 After the gate and drain are connected to M 1 P4 The source and gate are connected, R 1 02 Connected to M 1P8 The drain and M 1 P4 Between the source poles; M 1 P9 The source and M 1 P1 The source connection, M 1 P9 After the gate and drain are connected to M 1 P10 The source connection, M 1 P10 After the gate and drain are connected to M 1 P11 The source connection, M 1 P11 After the gate and drain are connected to M 1 P12 The source connection, M 1 P12 After the gate and drain are connected to M 1 P1 The source and M 1 P1 gate connection, R 1 01 Connected to M 1 P12 The drain and M 1 P1 Between the source poles; M 1 P13 The source and M 1 P2 The source connection, M 1 P13 After the gate and drain are connected to M 1 P14 The source connection, M 1 P14 After the gate and drain are connected to M 1 P15 The source connection, M 1 P15 After the gate and drain are connected, they are simultaneously connected to M. 1 P2 The gate and R 1 03 One end is connected, R 1 03 The other end is connected to the LD end; M 1 N1 The drain and M 1 P12 The drain connection, M 1 N1 The gate is used to receive the control signal hen_dsg, M 1 N2The drain and M 1 P8 The drain connection, M 1 N2 The gate is used to receive the control signal len_dsg, which is inversely phase to the control signal hen_dsg. 1 N2 The source and M 1 N4 The drain connection, M 1 N3 The drain and M 1 N1 The source connection, M 1 N3 The gate of M is simultaneously 1 N4 gate, M 1 N5 The gate and drain are connected, M 1 N3 The source and M 1 N4 The source, M 1 N5 The sources of M are all connected to the VSS terminal. 1 N5 The drain of A1 is connected to one end of A1, and the other end of A1 is connected to VDD. Figure 3 In this circuit, the enable signals hen_dsg and len_dsg are a pair of inverted signals. When hen_dsg is enabled, the DSW is in normal conduction mode, and the voltage at the CP terminal is the gate voltage of the DSW. When len_dsg is enabled, the DSW is in source follower mode, and the voltage at the BAT terminal is the gate voltage of the DSW. Specifically, the working principle of the DSW voltage selector when the DSW switches between the two modes is as follows: when the DSW switches from source follower mode to normal conduction mode, M... 1 P1 On, M 1 P3 and M 1 P4 When the circuit is turned off, the voltage at the CP terminal is higher than the voltage at the DSG terminal, and the output CP of the charge pump circuit flows through M... 1 P2 body diode (i.e.) Figure 3 The diode (connected by a dashed line) charges the gate-source capacitance of the DSW, raising the voltage at the DSG terminal. When the voltage difference between the DSG terminal and the LD terminal is higher than that of the diode connected to the M terminal... 1 P3 ~M 1 P15 When the sum of the on-state voltages is reached, the high-voltage switching transistor M... 1 P2 When the circuit is turned on, the path of the charging current changes to M. 1P2 The channel. Due to R 1 02 Since the resistance is large (i.e., in the megaohm range), the current in this path is in the nA range, thus not affecting the charging of the gate-source capacitor. Ultimately, the voltage at the DSG terminal is charged to the voltage at the CP terminal, and the DSW enters normal conduction mode. When the DSW switches from normal conduction mode to source follower mode, M... 1 P1 Off, M 1 P3 and M 1 P4 When M is turned on, 1 P2 It remains on, therefore the gate-source capacitance of the DSW is through M 1 P2 ~M 1 P4 The circuit discharges, and eventually the voltage at the DSG terminal drops to the voltage at the BAT terminal.

[0028] The final state of the DSW when it is turned off is that the gate voltage of the DSW is ground. In this invention, the gate voltage is reduced by continuously discharging the gate-source capacitance of the DSW to ground during the turn-off process. By controlling the discharge path state of the gate terminal to ground during this process, it can be ensured that an excessively large gate-source negative voltage does not occur. For example, Figure 4 This is a schematic diagram of a safety shutdown circuit. For example... Figure 4 As shown, the safety shutdown circuit includes: a PMOS switch M 2 P1 ~M 2 P9 NMOS switch M 2 N1 ~M 2 N3 Resistance R 2 01 R 2 02 R 2 03 R 2 04 Capacitor C 01 Current source A2, NOT gates F1-F4, AND gate Y1, Schmitt trigger SMT. B1 It is M 2 P1 and M 2 P2 The equivalent body diode, D B2 It is M 2 P3 M 2 P4 and M 2P5 The equivalent body diode. M 2 P1 After the gate and drain are connected to R 2 03 One end is connected, R 2 03 The other end connects to the DSG terminal, M 2 P1 The source and M 2 P2 The gate and drain are connected, M 2 P2 The source and R 2 01 One end is connected and used as the LD end, R 2 01 The other end and M 2 P5 The gate and drain are connected, M 2 P3 The source is connected to the DSG terminal, M 2 P3 After the gate and drain are connected to M 2 P4 The source connection, M 2 P4 After the gate and drain are connected to M 2 P5 The source connection, M 2 P6 The source and M 2 P2 The source connection, M 2 P6 The gate and M 2 P1 gate connection, M 2 P6 The drain and M 2 P7 The source connection, M 2 P7 After the gate and drain are connected to M 2 P8 The source connection, M 2 P8 After the gate and drain are connected, they are connected to the VSS terminal, C 01 and R 2 02 After parallel connection, connect to M 2 P7 Between the source and VSS terminals, M 2 P9 The gate and M 2 P5 The drain connection, M 2 P9 The source and M2 P3 The source connection, M 2 P9 The drain and M 2 N1 The drain connection, M 2 N1 The gate is used to receive the control signal cen_dsg, M 2 N1 The source is connected to the VSS terminal, M 2 N2 The drain and M 2 P9 The source connection, M 2 N2 The source is connected to the VSS terminal, R 2 04 Connected to M 2 N2 Between the gate and the VSS terminal, M 2 N2 The gate and M 2 N3 The source connection, M 2 N3 The drain of M is connected to one end of A2, and the other end of A2 is connected to the BAT terminal. 2 N3 The gate of Y1 is connected to the output of Y1. One input of Y1 is connected to the output of F2. The other input of Y1 is connected to the output of F4. The input of F2 is connected to the output of F1. The input of F1 is connected to the output of Schmitt trigger SMT. The input of Schmitt trigger SMT is connected to M... 2 P7 The source of F4 is connected, the input of F4 is connected to the output of F3, and the input of F3 is used to receive the control signal cen_dsg.

[0029] like Figure 4 As shown, the DSG port has two discharge paths to ground, namely M 2 P9 The switching state of the transistor (affected by the relationship between the voltage at the DSG terminal and the voltage at the LD terminal) and M 2 N1 The ground path Path1, composed of the switching transistors (controlled by the enable signal cen_dsg), and M 2 N2 The switching state of the transistor is affected by the enable signal cen_dsg and the capacitor C. 01 The voltage influence) controls the grounding path Path2. In the normal conduction state of the DSW, the voltage at the LD terminal is lower than the voltage at the DSG terminal, M 2 P9It is turned on, but the enable signal cen_dsg is low, M 2 N1 Shut down, Path1 is shut down; for M 2 N2 Pipe, M 2 P6 Off, C 01 The voltage is zero, but cen_dsg is low, M 2 N3 and M 2 N2 Neither of them conducts, so Path2 is off. When the external circuit triggers the discharge overcurrent protection or undervoltage protection, the enable signal cen_dsg jumps to a high level, M 2 N1 and M 2 N2 When the switching transistor is turned on, the gate-source capacitance of the DSW discharges through two ground-to-ground paths, Path1 and Path2. During the rapid voltage drop at the DSG terminal, the conduction of these two ground-to-ground discharge paths will sequentially turn off, specifically: first, M... 2 P9 Shut down, Path1 is shut down; then M 2 P6 When the circuit is turned on, the capacitor C at the LD end is connected. 01 Charge until the Schmitt trigger SMT input goes high, at which point M 2 N3 and M 2 N2 All of them become non-conductive, and Path2 is turned off. At this point, all discharge paths to ground of the gate-source capacitors of the DSW are turned off.

[0030] Combination Figure 1 and Figure 4 As shown, the DSG terminal is connected to the gate terminal of the discharge switch DSW through resistor R3. A resistor and a Zener diode are connected between the gate and source of the DSW to provide charge discharge and overvoltage protection. When both the on-chip discharge path to ground and the charging path of the gate-source capacitor are turned off, the gate-source capacitors share charge and are charged from the high-voltage PACK+ terminal to the DSG port through the external circuit, causing the DSG voltage to rise above the voltage at the LD terminal. At this time, M 2 N2 The switching transistor is triggered and turned on, C 01 The charging path is turned off, C 01 Through resistor R 2 02The gate-source capacitor of the DSW is gradually discharged to zero potential. Then, the gate-source capacitor is discharged again through two ground discharge paths, Path1 and Path2. Through the above-mentioned cyclic charging and discharging process, the lower envelope of the gate voltage of the DSW gradually decreases as the voltage at the LD terminal decreases. After a period of time, the gate voltage finally drops to zero, thereby achieving the safe shutdown of the DSW. Figure 5 This is a schematic diagram of the turn-off process of the discharge switch transistor. For example... Figure 5 As shown, during the turn-off process of the DSW, the voltage at the LD terminal continuously decreases. The gate voltage is maintained within a safe voltage difference range with the load terminal voltage through the repeated charging and discharging of the gate-source capacitor, ensuring that the voltage change is stable during the turn-off process and does not exceed the safe operating range of the DSW.

[0031] In this invention, the conduction state control signal of the CSW's DSW is regulated by the protection signal. Specifically, through... Figure 6 The control logic generation circuit shown generates control signals (i.e., enable signals) for the CSW voltage selector, DSW voltage selector, and safety shutdown circuit. By using these control signals to control the CSW voltage selector, DSW voltage selector, and safety shutdown circuit, the conduction state of the CSW's DSW is controlled. Specifically, as... Figure 6 As shown, the control logic generation circuit consists of a DSW control signal generation circuit and a CSW control signal generation circuit. The DSW control signal generation circuit is composed of NOR gates, multiple NOT gates, and multiple NAND gates, while the CSW control signal generation circuit is composed of NOR gates and NOT gates. The DSW control signal generation circuit generates a pair of inverted control signals hen_dsg and len_dsg for the DSW voltage selector, as well as the control signal cen_dsg for the safety shutdown circuit, based on the externally input undervoltage protection output signal uv_out, the conduction status signal sel_dsg of the discharge tube in the external circuit, and the externally input discharge overcurrent protection threshold voltage signal dsg_oc_out. The CSW control signal generation circuit generates a pair of inverted control signals oen_chg and cen_chg required by the CSW voltage selector, based on the externally input overvoltage protection output signal ov_out and the externally input charging overcurrent protection threshold voltage signal chg_oc_out. Figure 6As shown, for the discharge switch DSW, when the external circuit detects that the battery pack is in an undervoltage state or an overcurrent discharge condition occurs, the DSW's shutdown enable signal cen_dsg turns on, thereby triggering the safety shutdown circuit to protect the battery pack. For the charging switch CSW, when the external circuit detects that the battery pack is in an overvoltage state or an overcurrent charging condition occurs, the CSW's shutdown enable signal cen_chg turns on, thereby triggering the CSW to turn off to prevent the battery pack from being overcharged or damaged by overcurrent. The above control logic ensures that CSW and DSW can respond to protection signals in a timely manner under abnormal conditions to achieve safe shutdown.

[0032] Compared to current protection technologies for high-side MOSFETs that primarily focus on protecting power switches under short-circuit or overload conditions, this invention not only provides a gate voltage selection control scheme—precisely regulating the gate voltage through a voltage selector to ensure the stability and reliability of the charging and discharging process—but also further implements pulse-type discharge protection for the discharge switch connected to the load during turn-off. Specifically, during the turn-off process of the discharge switch, a safety turn-off circuit is set up to gradually release the charge from the gate-source capacitor in a pulse manner, thereby effectively preventing the gate-source voltage from becoming too high and ensuring the safe turn-off of the discharge switch, thus enhancing the safety and reliability of the entire circuit.

[0033] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0035] In this specification, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. While different embodiments may describe certain measures, this does not mean that these measures cannot be combined to produce a good effect.

[0036] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A pulse-type drive circuit for high-side charge / discharge protection of battery packs, characterized in that, include: Battery pack module, charging switch module, discharging switch module, charge pump module, voltage selector, safety shutdown circuit module, and control logic generation circuit; The battery pack module is connected to the charging switch module and the charge pump module. The charge pump module is connected to the voltage selector. The voltage selector is connected to the charging switch module, the discharging switch module, and the safety shutdown circuit module. The charging switch module is connected to the discharging switch module, and the safety shutdown circuit module is connected to the discharging switch module. The control logic generation circuit is connected to the voltage selector and the safety shutdown circuit module. The charging switch CSW in the charging switch module is used to control the on / off state of the charging circuit of the battery pack in the battery pack module; the discharging switch DSW in the discharging switch module is used to control the on / off state of the discharging circuit of the battery pack. The charge pump module is used to boost the input voltage; the control logic generation circuit is used to generate different control signals required by the voltage selector and the safety shutdown circuit module; the voltage selector is used to control the gate voltage of CSW and DSW by controlling the switching state of the charging and discharging path between the input and output, so as to control the on and off of CSW and DSW. The safety shutdown circuit module is used to control the gate-source voltage of the DSW within a preset safe range during the DSW shutdown process. The voltage selector includes: a CSW voltage selector and a DSW voltage selector; The CSW voltage selector is connected to the output and input terminals of the charge pump module, the gate of the CSW, and the control logic generation circuit. The CSW voltage selector is used to control the gate voltage of the CSW by controlling the switching state of the charging and discharging path between the input and the output, so as to control the on and off of the CSW. The DSW voltage selector is connected to the output and input terminals of the charge pump module, the first terminal of the discharge switch module, the first terminal of the safety shutdown circuit module, and the control logic generation circuit. The DSW voltage selector is used to control the gate voltage of the DSW by controlling the switching state of the charging and discharging path between the input and the output, so as to control the on and off of the DSW. The CSW voltage selector includes: a PMOS switch M P1 ~M P12 NMOS switch M N1 ~ M N5 Resistance R 01 R 02 Current source A0; M P1 The drain of M is connected to the output terminal of the charge pump module. P1 The gate and M P2 gate connection, M P1 The source and M P2 The source connection, M P2 The drain of the CSW is simultaneously connected to the gate and M. P4 The drain connection, M P4 The source and M P3 The source connection, M P4 The gate and M P3 gate connection, M P3 The drain of M is connected to the input terminal of the charge pump module. P5 The source and M P4 The source connection, M P5 After the drain and gate are connected to M P6 The source connection, M P6 After the drain and gate are connected to M P7 The source connection, M P7 After the drain and gate are connected to M P8 The source connection, M P8 After the drain and gate are connected, they are simultaneously connected with M. P5 The source and M P4 gate connection, R 02 Connected in M P5 The source and M P8 Between the drain and the M electrode; P9 The source and M P1 The source connection, M P9 After the drain and gate are connected to M P10 The source connection, M P10 After the drain and gate are connected to M P11 The source connection, M P11 After the drain and gate are connected to M P12 The source connection, M P12 After the drain and gate are connected, they are simultaneously connected with M. P9 The source and M P2 gate connection, R 01 Connected to M P9 The source and M P12 Between the drain and the M electrode; N1 The drain and M P12 The drain connection, M N1 The gate is used to receive the control signal oen_chg, M N1 The source and M N4 The drain connection, M N4 The gate of M is simultaneously N3 Gate and drain, M N5 gate connection, M N4 The source and M N3 The source, M N5 The sources of M are all connected to the VSS terminal. N3 After the drain and gate are connected, they are also connected to one end of A0, and the other end of A0 is connected to VDD. N5 The drain and M N2 The source connection, M N2 The drain and M P8 The drain connection, M N2 The gate is used to receive the control signal cen_chg, which is inverse of the control signal oen_chg.

2. The pulse-type drive circuit for high-side charge / discharge protection of battery packs according to claim 1, characterized in that, The DSW voltage selector includes: a PMOS switch M 1 P1 ~M 1 P15 NMOS switch M 1 N1 ~ M 1 N5 Resistance R 1 01 R 1 02 R 1 03 and current source A1; M 1 P1 The source of M is connected to the output terminal of the charge pump module. 1 P1 The drain and M 1 P2 The drain connection, M 1 P2 The source of M is connected to the first terminal of the discharge switch module. 1 P3 The drain of M is connected to the input terminal of the charge pump module. 1 P3 The source and M 1 P4 The source connection, M 1 P4 The drain and M 1 P2 The drain connection, M 1 P4 The gate and M 1 P3 gate connection, M 1 P5 The source and M 1 P4 The source connection, M 1 P5 After the gate and drain are connected to M 1 P6 The source connection, M 1 P6 After the gate and drain are connected to M 1 P7 The source connection, M 1 P7 After the gate and drain are connected to M 1 P8 The source connection, M 1 P8 After the gate and drain are connected to M 1 P4 The source and gate are connected, R 1 02 Connected to M 1 P8 The drain and M 1 P4 Between the source poles; M 1 P9 The source and M 1 P1 The source connection, M 1 P9 After the gate and drain are connected to M 1 P10 The source connection, M 1 P10 After the gate and drain are connected to M 1 P11 The source connection, M 1 P11 After the gate and drain are connected to M 1 P12 The source connection, M 1 P12 After the gate and drain are connected to M 1 P1 The source and M 1 P1 gate connection, R 1 01 Connected in M 1 P12 The drain and M 1 P1 Between the source poles; M 1 P13 The source and M 1 P2 The source connection, M 1 P13 After the gate and drain are connected to M 1 P14 The source connection, M 1 P14 After the gate and drain are connected to M 1 P15 The source connection, M 1 P15 After the gate and drain are connected, they are simultaneously connected to M. 1 P2 The gate and R 1 03 One end is connected, R 1 03 The other end is connected to the first end of the safety shutdown circuit module; M 1 N1 The drain and M 1 P12 The drain connection, M 1 N1 The gate is used to receive the control signal hen_dsg, M 1 N2 The drain and M 1 P8 The drain connection, M 1 N2 The gate is used to receive the control signal len_dsg, which is inversely phase to the control signal hen_dsg. 1 N2 The source and M 1 N4 The drain connection, M 1 N3 The drain and M 1 N1 The source connection, M 1 N3 The gate of M is simultaneously 1 N4 gate, M 1 N5 The gate and drain are connected, M 1 N3 The source and M 1 N4 The source, M 1 N5 The sources of M are all connected to the VSS terminal. 1 N5 The drain of A1 is connected to one end of A1, and the other end of A1 is connected to VDD.

3. The pulse drive circuit for high-side charge / discharge protection of battery packs according to claim 1, characterized in that, The charging switch module includes: CSW, resistor R1, and Zener diode D5; the source of CSW is connected to one end of R1 and the anode of D5, the other end of R1 and the cathode of D5 are both connected to the gate of CSW, and the drain of CSW is connected to the drain of DSW.

4. The pulse-type drive circuit for high-side charge / discharge protection of battery packs according to claim 1 or 2, characterized in that, The discharge switch module includes: DSW, resistor R2, resistor R3, and Zener diode D6; The drain of DSW is connected to the drain of CSW, the gate of DSW is connected to one end of R3, the other end of R3 serves as the first end of the discharge switch module, and the end of R3 connected to the gate of DSW is also connected to one end of R2 and the cathode of D6, while the other end of R2 and the anode of D6 are both connected to the source of DSW.

5. The pulse drive circuit for high-side charge / discharge protection of battery packs according to claim 1, characterized in that, The safety shutdown circuit module includes: a safety shutdown circuit; the safety shutdown circuit includes: a PMOS switching transistor M. 2 P1 ~M 2 P9 NMOS switch M 2 N1 ~ M 2 N3 Resistance R 2 01 R 2 02 R 2 03 R 2 04 Capacitor C 01 Current source A2, NOT gates F1~F4, AND gate Y1, Schmitt trigger SMT; M 2 P1 After the gate and drain are connected to R 2 03 One end is connected, R 2 03 The other end is connected to the first end of the discharge switch module, M 2 P1 The source and M 2 P2 The gate and drain are connected, M 2 P2 The source and R 2 01 One end of R is connected and serves as the first terminal of the safety shutdown circuit module. 2 01 The other end and M 2 P5 The gate and drain are connected, M 2 P3 The source of M is connected to the first terminal of the discharge switch module. 2 P3 After the gate and drain are connected to M 2 P4 The source connection, M 2 P4 After the gate and drain are connected to M 2 P5 The source connection, M 2 P6 The source and M 2 P2 The source connection, M 2 P6 The gate and M 2 P1 gate connection, M 2 P6 The drain and M 2 P7 The source connection, M 2 P7 After the gate and drain are connected to M 2 P8 The source connection, M 2 P8 After the gate and drain are connected, they are connected to the VSS terminal, C 01 and R 2 02 After parallel connection, connect to M 2 P7 Between the source and VSS terminals, M 2 P9 The gate and M 2 P5 The drain connection, M 2 P9 The source and M 2 P3 The source connection, M 2 P9 The drain and M 2 N1 The drain connection, M 2 N1 The gate is used to receive the control signal cen_dsg, M 2 N1 The source is connected to the VSS terminal, M 2 N2 The drain and M 2 P9 The source connection, M 2 N2 The source is connected to the VSS terminal, R 2 04 Connected to M 2 N2 Between the gate and the VSS terminal, M 2 N2 The gate and M 2 N3 The source connection, M 2 N3 The drain of M is connected to one end of A2, and the other end of A2 is connected to the input terminal of the charge pump module. 2 N3 The gate of Y1 is connected to the output of Y1. One input of Y1 is connected to the output of F2. The other input of Y1 is connected to the output of F4. The input of F2 is connected to the output of F1. The input of F1 is connected to the output of Schmitt trigger SMT. The input of Schmitt trigger SMT is connected to M... 2 P7 The source terminal of F4 is connected, the input terminal of F4 is connected to the output terminal of F3, and the input terminal of F3 is used to receive the control signal cen_dsg.

6. The pulse drive circuit for high-side charge / discharge protection of battery packs according to claim 5, characterized in that, The safety shutdown circuit module also includes: resistor R 16 R 16 One end and M 2 P2 The source and M 2 P6 The source connection, R 16 The other end is connected to the source of the DSW.

7. The pulse-type drive circuit for high-side charge / discharge protection of battery packs according to claim 1, characterized in that, The control logic generation circuit is used to generate a pair of inverted control signals hen_dsg and len_dsg required by the voltage selector, and a control signal cen_dsg required by the safety shutdown circuit module, based on the externally input undervoltage protection output signal uv_out, the conduction status signal sel_dsg of the discharge tube in the external circuit, and the externally input discharge overcurrent protection threshold voltage signal dsg_oc_out. It also generates a pair of inverted control signals oen_chg and cen_chg required by the voltage selector based on the externally input overvoltage protection output signal ov_out and the externally input charging overcurrent protection threshold voltage signal chg_oc_out.

8. The pulse drive circuit for high-side charge / discharge protection of battery packs according to claim 1, characterized in that, The charge pump module includes a charge pump circuit and a capacitor C2. C2 is connected between the input and output terminals of the charge pump circuit. The input terminal of the charge pump circuit serves as the input terminal of the charge pump module, and the output terminal of the charge pump circuit serves as the output terminal of the charge pump module.

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