A short circuit protection circuit suitable for a half-bridge switching topology

Abstract

The utility model discloses a kind of short-circuit protection circuit suitable for half-bridge type switch topology, it is related to short-circuit protection circuit design field, half-bridge type switch topology includes power supply, bus capacitor C1, high-side switch tube Q1 and low-side switch tube Q2, short-circuit protection circuit includes sampling resistance, protection switch tube Q3 and protection module;The second electrode of high-side switch tube Q1 is connected with the first electrode of low-side switch tube Q2, one end of bus capacitor C1 is connected with the second electrode of low-side switch tube Q2 and power supply negative pole, the first electrode of high-side switch tube Q1 is connected with the other end of bus capacitor C1 and the second electrode of protection switch tube Q3 by sampling resistance;Protection module is connected with sampling resistance and the third electrode of protection switch tube Q3, protection module is used to control protection switch tube Q3 to be turned off when the voltage at both ends of sampling resistance is greater than preset protection threshold value.The circuit can be half-bridge type switch topology and add second level protection means, improve the stability and security of operation.

Description

Technical Field

[0001] This utility model relates to the field of short-circuit protection circuit design, and in particular to a short-circuit protection circuit suitable for a half-bridge switching topology. Background Technology

[0002] In a half-bridge switching topology, the power circuits of the high / low-side switching devices Q1 / Q2 operate in a high-frequency, high-voltage switching environment, making them highly susceptible to electromagnetic interference (EMI). This interference directly affects the normal operation of the preceding ICs, disrupts the stability of transmitted signals, and may cause waveform distortion and aberration, ultimately leading to circuit failures and significantly reducing the reliability and safety of the circuit. Furthermore, the busbar capacitors in the circuit are prone to performance degradation and even failure under long-term operation in a high-frequency, high-voltage switching environment. Current circuits lack specific protection designs for the busbar capacitors; once a capacitor fails, it will directly trigger a system failure, significantly weakening the overall system's safe operation level.

[0003] Although the gate driver (Driver IC circuit section) of the high / low side switching device has short-circuit protection detection capability, the driver itself may fail (such as device failure, signal abnormality, etc.). Relying solely on its own protection is insufficient to fully cover the risk. Therefore, an additional independent protection mechanism is required to further improve the fault protection redundancy and operational reliability of the circuit. Utility Model Content

[0004] In response to the aforementioned problems and technical requirements, the applicant has proposed a short-circuit protection circuit suitable for half-bridge switching topologies.

[0005] The technical solution of this utility model is as follows: A short-circuit protection circuit suitable for a half-bridge switching topology, wherein the half-bridge switching topology includes a power supply, a busbar capacitor C1, a high-side switch Q1 and a low-side switch Q2, and the short-circuit protection circuit includes a sampling resistor, a protection switch Q3 and a protection module. The second electrode of the high-side switch Q1 is connected to the first electrode of the low-side switch Q2. One end of the busbar capacitor C1 is connected to the second electrode of the low-side switch Q2 and the negative terminal of the power supply. The first electrode of the high-side switch Q1 is connected to the other end of the busbar capacitor C1 and the second electrode of the protection switch Q3 through a sampling resistor. The first electrode of the protection switch Q3 is connected to the positive terminal of the power supply. The protection module is connected to the sampling resistor and the third electrode of the protection switch Q3. The protection module is used to collect the voltage across the sampling resistor and control the protection switch Q3 to turn off when the voltage across the sampling resistor is greater than a preset protection threshold.

[0006] The further technical solution is that the protection module includes a driver chip U1, connector H1, connector H2, interface RF1, interface CN2, resistors R10, R18, R20, R34, R35, R36, R37, R38, R39, capacitors C18, C19, C47, and C48. The first pin of the interface CN2 is connected to one end of the sampling resistor and one end of the resistor R18. The second pin of the interface CN2 is connected to the other end of the sampling resistor and connected to the power supply ground. The other end of the resistor R18 is connected to the OC pin of the driver chip U1. The OC pin is also connected to the power supply ground through the capacitor C47. The fifth pin of the interface RF1 is connected to the third pin of the connector H2 and connected to the analog ground through resistor R39. The second pin of the connector H2 is connected to the third pin and the second pin of the connector H2 is connected to the IN+ pin of the driver chip U1. The first pin of the connector H2 is connected to the first power supply voltage through resistor R38.

[0007] A further technical solution is that the VCC pin of the driver chip U1 is connected to analog ground through resistor R10, capacitor C19 and capacitor C18, and is connected to the first power supply voltage; the IN+ pin of the driver chip U1 is connected to the GND pin through capacitor C48 and connected to analog ground. The OUTL pin of the driver chip U1 is connected to one end of resistors R34 and R35, and the OUTH pin of the driver chip U1 is connected to one end of resistors R36 and R37. The other end of resistors R34, R35, R36, and R37 is connected to the CLMPI pin of the driver chip U1 and the first to sixth pins of connector H1, and connected to the power supply ground through resistor R20. The first to sixth pins of connector H1 are connected to the third electrode of the protection switch Q3, and the ninth to fourteenth pins of connector H1 are connected to the second electrode of the protection switch Q3 and connected to the power supply ground.

[0008] The further technical solution is that the protection module also includes resistors R11, R12, R13, R41, R42, capacitors C44, C45, and C46, ​​indicator LED5 and indicator LED6, and the VEE pin of the driver chip U1 is connected to the second power supply voltage, and the VDD pin of the driver chip U1 is connected to the third power supply voltage. The RDY pin of driver chip U1 is connected to the negative terminal of indicator LED5 and one end of resistor R11. The FLT pin of driver chip U1 is connected to the negative terminal of indicator LED6 and one end of resistor R12. The RST pin of driver chip U1 is connected to one end of resistor R13. The positive terminal of indicator LED5 is connected to one end of resistor R41. The positive terminal of indicator LED6 is connected to one end of resistor R42. The other ends of resistors R11, R12, R13, R41, and R42 are connected to the first power supply voltage. The RDY pin is connected to analog ground through capacitor C46. The FLT pin is connected to analog ground through capacitor C45. The RST pin is connected to analog ground through capacitor C44.

[0009] A further technical solution includes a power module, which includes a power input module. The power input module includes an interface CN1, a fuse F2, a Schottky diode D3, a common-mode filter L2, an inductor L1, a capacitor C13, a capacitor C14, a resistor R21, and an indicator LED1. The first pin of interface CN1 is connected to the input power supply and one end of fuse F2. The other end of fuse F2 is connected to the negative terminal of Schottky diode D3, one end of capacitor C12, and the fourth pin of common-mode filter L2. The positive terminal of Schottky diode D3 is connected to the other end of capacitor C12 and the first pin of common-mode filter L2 and grounded. The third pin of common-mode filter L2 is connected to one end of capacitor C13 and one end of inductor L1. The second pin of common-mode filter L2 is connected to the other end of capacitor C13 and one end of capacitor C14 and grounded. The other end of inductor L1 is connected to the other end of capacitor C14 to form the output terminal of the power input module. The output terminal of the power input module is connected to one end of resistor R21. The other end of resistor R21 is connected to the positive terminal of indicator LED1. The negative terminal of indicator LED1 is grounded.

[0010] A further technical solution is that the power supply module further includes a first output module, which is used to output a first power supply voltage. The first output module includes a voltage regulator U2, a voltage regulator U6, a capacitor C15, a capacitor C16, a capacitor C19, a resistor R22, and an indicator LED2. The input terminal of the voltage regulator U2 is connected to the output terminal of the power input module. The ground terminal of the voltage regulator U2 is grounded. The positive output terminal of the voltage regulator U2 is connected to the negative output terminal of the voltage regulator U2 through capacitor C19, and the negative output terminal of the voltage regulator U2 is connected to analog ground. The input terminal of voltage regulator U6 is connected to the positive output terminal of voltage regulator U2, and is connected to the ground terminal of voltage regulator U6 through capacitor C16. The ground terminal of voltage regulator U6 is connected to analog ground. The output terminal of voltage regulator U6 is connected to analog ground through capacitor C15. The input terminal of voltage regulator U6 is connected to the positive terminal of indicator LED2 through resistor R22. The negative terminal of indicator LED2 is connected to analog ground.

[0011] A further technical solution is that the power supply module also includes a conversion module, which includes a voltage regulator U3, a Schottky diode D5, an inductor L3, an inductor L4, a capacitor C20, a capacitor C21, a capacitor C22, and a capacitor C23. The output terminal of the power input module is connected to the positive terminal of Schottky diode D5, the negative terminal of Schottky diode D5 is connected to the input terminal of voltage regulator U3, the ground terminal of voltage regulator U3 is grounded, the positive output terminal of voltage regulator U3 is connected to one end of inductor L3 and one end of capacitor C20, the other end of inductor L3 is connected to one end of capacitor C21, the other end of capacitor C20 is connected to the other end of capacitor C21, one end of capacitor C23 and one end of capacitor C22, the negative output terminal of voltage regulator U3 is connected to the other end of capacitor C23 and one end of inductor L4, and the other end of inductor L4 is connected to the other end of capacitor C22.

[0012] A further technical solution is that the power supply module further includes a second output module, which is used to output a second power supply voltage. The second output module includes a voltage regulator U4, resistors R3, R4, R5, R6, capacitors C24, C25, and C27. The IN pin of voltage regulator U4 is connected to the other end of inductor L3. The IN pin of voltage regulator U4 is also connected to power ground through capacitor C24. Capacitor C25 is connected in parallel with capacitor C24. The IN pin of voltage regulator U4 is connected to one end of resistor R3. The other end of resistor R3 is connected to the EN pin of voltage regulator U4 and one end of resistor R4. The other end of resistor R4 is connected to power ground. The OUT pin of voltage regulator U4 is connected to one end of resistor R6 and one end of capacitor C27, forming a second power supply voltage output terminal. The other end of resistor R6 is connected to one end of resistor R5 and the FB pin of voltage regulator U4. The other end of resistor R5 is connected to the other end of capacitor C27 and connected to power ground.

[0013] A further technical solution is that the power supply module also includes a third output module, which is used to output a third power supply voltage. The third output module includes a voltage regulator U5, capacitors C30, C31, C32, and C43, an inductor L5, resistors R7, R8, and R9, and a Schottky diode D4. One end of inductor L5 is connected to the other end of inductor L4. One end of inductor L5 is connected to power ground through capacitor C43. Capacitor C30 is connected in parallel with capacitor C43. The other end of inductor L5 is connected to the positive terminal of Schottky diode D4 and the SW pin of voltage regulator U5. One end of inductor L5 is also connected to the CTRL pin and VIN pin of voltage regulator U5. The GND pin of voltage regulator U5 is grounded. The COMP pin of voltage regulator U5 is connected to one end of capacitor C32 through resistor R9. The other end of capacitor C32 is grounded. The FB pin of voltage regulator U5 is connected to one end of resistor R7 and resistor R8. The other end of resistor R7 is connected to one end of capacitor C31 and grounded. The other end of resistor R8 is connected to the other end of capacitor C31 and the negative terminal of Schottky diode D4 to form the second power supply voltage output terminal.

[0014] A further technical solution is that the power supply module also includes a supplementary capacitor module, which includes capacitors C33, C34, C35, C36, C37, C38, C39, C40, C41, C42, resistors R23 and R24, indicator LED3 and indicator LED4. One end of capacitor C33 is connected to the second power supply voltage output terminal, and the other end of capacitor C33 is connected to the power supply ground. Capacitors C34, C35, C36, and C37 are connected in parallel with capacitor C33. The second power supply voltage output terminal is connected to the negative terminal of indicator LED4, and the positive terminal of indicator LED4 is connected to the power supply ground through resistor R24. One end of capacitor C38 is connected to the third power supply voltage output terminal, and the other end of capacitor C38 is connected to the power supply ground. Capacitors C39, C40, C41, and C42 are connected in parallel with capacitor C38. The third power supply voltage output terminal is connected to the positive terminal of indicator LED3 through resistor R23, and the negative terminal of indicator LED3 is connected to the power supply ground.

[0015] The beneficial technical effects of this utility model are: In the short-circuit protection circuit design provided by this utility model, the acquisition point is located between the high-side switch Q1 (+) and the busbar capacitor (+), while the protection switch is located between the busbar capacitor (+) and the power output (+), forming a "rear-stage acquisition, front-stage control" architecture, and achieving electrical isolation between the high-voltage source and the busbar capacitor, switch Q1, and switch Q2. Busbar current changes can be monitored without interfering with the normal operation of switch Q1 and switch Q2. When a short circuit occurs, the high-voltage circuit is cut off, protecting the downstream high / low-side switches Q1 / Q2, thus adding a second level of protection to the half-bridge switch topology and improving the stability and safety of the entire system. This functional circuit design features flexibility, convenience, good applicability, high stability, and low cost. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of one embodiment of the short-circuit protection circuit provided by this utility model.

[0017] Figure 2 This is a circuit diagram of one embodiment of the protection module provided by this utility model.

[0018] Figure 3 This is a circuit diagram of one embodiment of the power input module provided by this utility model.

[0019] Figure 4 This is a circuit schematic diagram of one embodiment of the first output module provided by this utility model.

[0020] Figure 5 This is a circuit diagram of one embodiment of the conversion module provided by this utility model.

[0021] Figure 6 This is a circuit diagram of one embodiment of the second output module provided by this utility model.

[0022] Figure 7 This is a circuit diagram of one embodiment of the third output module provided by this utility model.

[0023] Figure 8 This is a circuit diagram of one embodiment of the supplementary capacitor module provided by this utility model. Detailed Implementation

[0024] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure.

[0025] This invention provides a short-circuit protection circuit suitable for a half-bridge switching topology, such as... Figure 1As shown, the half-bridge switching topology includes a power supply, a busbar capacitor C1, a high-side switch Q1, and a low-side switch Q2. The short-circuit protection circuit includes a sampling resistor (i.e., a precision resistor R2), a protection switch Q3, and a protection module. The second electrode of the high-side switch Q1 is connected to the first electrode of the low-side switch Q2. One end of the busbar capacitor C1 is connected to the second electrode of the low-side switch Q2 and the negative terminal of the power supply. The first electrode of the high-side switch Q1 is connected to the other end of the busbar capacitor C1 and the second electrode of the protection switch Q3 through a sampling resistor. The first electrode of the protection switch Q3 is connected to the positive terminal of the power supply. The protection module is connected to the sampling resistor and the third electrode of the protection switch Q3. The protection module is used to collect the voltage across the sampling resistor and control the protection switch Q3 to turn off when the voltage across the sampling resistor is greater than a preset protection threshold, so as to achieve short circuit protection.

[0026] Specifically, the high-side switch Q1, low-side switch Q2, and protection switch Q3 can all be NMOS transistors. For NMOS transistors, the first electrode is the drain, the second electrode is the source, and the third electrode is the gate. The protection module collects the loop current by sampling the voltage across a sampling resistor. The voltage across the sampling resistor synchronously reflects current changes. When a short circuit occurs, the voltage across the sampling resistor collected by the protection module exceeds a preset protection threshold, and the protection switch Q3 is immediately turned off to cut off the circuit path, thus achieving short-circuit protection. This short-circuit protection circuit does not affect the operation of the high / low-side switching devices Q1 / Q2 during normal operation of the power loop. Furthermore, the preset protection threshold can be set as needed. When a short-circuit fault occurs in the power loop, the protection module can receive the fault signal immediately and provide rapid feedback. In high-frequency, high-voltage switching environments, it ensures stable signal transmission and control feedback, and possesses strong anti-interference capabilities. Meanwhile, a modular design can be adopted, in which the short-circuit protection circuit is set on the PCB and quickly integrated with the half-bridge switch topology through a reserved interface to achieve the short-circuit protection function. It is compact, highly integrated, and easy to troubleshoot, repair and replace.

[0027] For details, please refer to Figure 2 The protection module includes a driver chip U1, connectors H1 and H2, interface RF1, interface CN2, resistors R10, R18, R20, R34, R35, R36, R37, R38, and R39, and capacitors C18, C19, C47, and C48. The first pin of interface CN2 is connected to one end of the sampling resistor and one end of resistor R18. The second pin of interface CN2 is connected to the other end of the sampling resistor and connected to power ground (PGND). The other end of resistor R18 is connected to the OC pin of driver chip U1. The OC pin is also connected to power ground through capacitor C47. The fifth pin of interface RF1 is connected to the third pin of connector H2 and connected to analog ground (AGND) through resistor R39. The second pin of connector H2 is connected to the third pin. The second pin of connector H2 is connected to the IN+ pin of driver chip U1. The first pin of connector H2 is connected to the first power supply voltage through resistor R38.

[0028] The driver chip U1 is model UCC21710, which integrates OC acquisition, signal processing, and output control functions, and has strong anti-interference capabilities. The driver chip U1 acquires the voltage across a precision resistor and compares it with a preset protection threshold to control the switching on and off of the protection switch, thereby achieving the protection function. The VCC pin of the driver chip U1 is connected to analog ground via resistor R10, capacitor C19, and capacitor C18, and is connected to the first power supply voltage; the IN+ pin of the driver chip U1 is connected to the GND pin via capacitor C48 and is also connected to analog ground. The OUTL pin of the driver chip U1 is connected to one end of resistors R34 and R35, and the OUTH pin of the driver chip U1 is connected to one end of resistors R36 and R37. The other end of resistors R34, R35, R36, and R37 is connected to the CLMPI pin of the driver chip U1 and the first to sixth pins of connector H1, and connected to the power supply ground through resistor R20. The first to sixth pins of connector H1 are connected to the third electrode of the protection switch Q3, and the ninth to fourteenth pins of connector H1 are connected to the second electrode of the protection switch Q3 and connected to the power supply ground.

[0029] In practice, a continuously high-level 5V signal is output to the driver chip U1 through interface RF1 to enable the driver chip U1 to operate normally. Under normal conditions, the driver chip U1 outputs a high-level signal to the protection switch Q3 through connector H1 to keep the protection switch in the on state. The driver chip U1 collects the voltage across the sampling resistor in real time. When the voltage across the sampling resistor is greater than the preset protection threshold, the driver chip U1 outputs a low-level signal to the protection switch Q3 through connector H1 to quickly turn off the protection switch Q3, cutting off the circuit path to achieve short-circuit protection.

[0030] Furthermore, the protection module also includes resistors R11, R12, R13, R41, R42, capacitors C44, C45, and C46, ​​indicator LED5, and indicator LED6. The VEE pin of the driver chip U1 is connected to a second power supply voltage, and the VDD pin of the driver chip U1 is connected to a third power supply voltage. The RDY pin of driver chip U1 is connected to the negative terminal of indicator LED5 and one end of resistor R11. The FLT pin of driver chip U1 is connected to the negative terminal of indicator LED6 and one end of resistor R12. The RST pin of driver chip U1 is connected to one end of resistor R13. The positive terminal of indicator LED5 is connected to one end of resistor R41. The positive terminal of indicator LED6 is connected to one end of resistor R42. The other ends of resistors R11, R12, R13, R41, and R42 are connected to the first power supply voltage. The RDY pin is connected to analog ground through capacitor C46. The FLT pin is connected to analog ground through capacitor C45. The RST pin is connected to analog ground through capacitor C44.

[0031] In this embodiment, the first to third power supply voltages are -5V, -5V, and +15V, respectively. The first to third power supply voltages are provided by a power supply module. The power supply module is designed to ensure stable and reliable power supply. The power supply module includes a power input module. The power input module includes an interface CN1, a fuse F2, a Schottky diode D3, a common-mode filter L2, an inductor L1, a capacitor C13, a capacitor C14, a resistor R21, and an indicator LED1. Please refer to Figure 3 The first pin of interface CN1 is connected to the input power supply and one end of fuse F2. The second pin of CN1 is grounded (GND1). The other end of fuse F2 is connected to the negative terminal of Schottky diode D3, one end of capacitor C12, and the fourth pin of common-mode filter L2. The positive terminal of Schottky diode D3 is connected to the other end of capacitor C12 and the first pin of common-mode filter L2 and grounded. The third pin of common-mode filter L2 is connected to one end of capacitor C13 and one end of inductor L1. The second pin of common-mode filter L2 is connected to the other end of capacitor C13 and one end of capacitor C14 and grounded. The other end of inductor L1 is connected to the other end of capacitor C14 to form the output terminal of the power input module. The output terminal of the power input module is connected to one end of resistor R21. The other end of resistor R21 is connected to the positive terminal of indicator LED1, and the negative terminal of indicator LED1 is grounded. The power input module filters the input power supply (24V) and outputs it. Indicator LED1 is used to indicate the output status of the power input module.

[0032] Furthermore, the power module also includes a first output module, which is used to output a first power supply voltage. The first output module includes a voltage regulator U2, a voltage regulator U6, a capacitor C15, a capacitor C16, a capacitor C19, a resistor R22, and an indicator LED2. The input terminal of voltage regulator U2 is connected to the output terminal of the power input module. The ground terminal of voltage regulator U2 is grounded. The positive output terminal of voltage regulator U2 is connected to the negative output terminal of voltage regulator U2 through capacitor C19, and the negative output terminal of voltage regulator U2 is connected to analog ground. The input terminal of voltage regulator U6 is connected to the positive output terminal of voltage regulator U2, and is connected to the ground terminal of voltage regulator U6 through capacitor C16. The ground terminal of voltage regulator U6 is connected to analog ground. The output terminal of voltage regulator U6 is connected to analog ground through capacitor C15. The input terminal of voltage regulator U6 is connected to the positive terminal of indicator LED2 through resistor R22, and the negative terminal of indicator LED2 is connected to analog ground. Voltage regulator U2 converts the 24V input power voltage to a +5V power voltage, and voltage regulator U6 converts the +5V power voltage to a -5V power voltage. The output terminal of voltage regulator U6 serves as the output terminal of the first output module, outputting the first power voltage.

[0033] The power module also includes a conversion module, which includes a voltage regulator U3, a Schottky diode D5, an inductor L3, an inductor L4, a capacitor C20, a capacitor C21, a capacitor C22, and a capacitor C23. The output terminal of the power input module is connected to the anode of Schottky diode D5, and the cathode of Schottky diode D5 is connected to the input terminal of voltage regulator U3. The ground terminal of voltage regulator U3 is grounded. The positive output terminal of voltage regulator U3 is connected to one end of inductor L3 and one end of capacitor C20. The other end of inductor L3 is connected to one end of capacitor C21. The other end of capacitor C20 is connected to the other end of capacitor C21, one end of capacitor C23, and one end of capacitor C22. The negative output terminal of voltage regulator U3 is connected to the other end of capacitor C23 and one end of inductor L4. The other end of inductor L4 is connected to the other end of capacitor C22. Voltage regulator U3 converts the 24V input power supply voltage into power supply voltages VDD and VEE.

[0034] The power module also includes a second output module, which is used to output a second power supply voltage. Please refer to [reference needed]. Figure 6 The second output module includes a voltage regulator U4, resistors R3, R4, R5, R6, capacitors C24, C25, and C27. The IN pin of voltage regulator U4 is connected to the other end of inductor L3. The IN pin of voltage regulator U4 is also connected to power ground via capacitor C24. Capacitor C25 is connected in parallel with capacitor C24. The IN pin of voltage regulator U4 is connected to one end of resistor R3. The other end of resistor R3 is connected to the EN pin of voltage regulator U4 and one end of resistor R4. The other end of resistor R4 is connected to power ground. The OUT pin of voltage regulator U4 is connected to one end of resistor R6 and one end of capacitor C27, forming the second power supply voltage output terminal. The other end of resistor R6 is connected to one end of resistor R5 and the FB pin of voltage regulator U4. The other end of resistor R5 is connected to the other end of capacitor C27 and connected to power ground. The model of voltage regulator U4 includes TPS72301DBVR. Voltage regulator U4 converts the power supply voltage VEE into a second power supply voltage (-5V).

[0035] The power module also includes a third output module, which is used to output a third power supply voltage. Please refer to [reference needed]. Figure 7 The third output module includes a voltage regulator U5, capacitors C30, C31, C32, and C43, an inductor L5, resistors R7, R8, and R9, and a Schottky diode D4. One end of inductor L5 is connected to the other end of inductor L4. One end of inductor L5 is connected to power ground through capacitor C43. Capacitor C30 is connected in parallel with capacitor C43. The other end of inductor L5 is connected to the positive terminal of Schottky diode D4 and the SW pin of voltage regulator U5. One end of inductor L5 is also connected to the CTRL pin and VIN pin of voltage regulator U5. The GND pin of voltage regulator U5 is grounded. The COMP pin of voltage regulator U5 is connected to one end of capacitor C32 through resistor R9. The other end of capacitor C32 is grounded. The FB pin of voltage regulator U5 is connected to one end of resistor R7 and resistor R8. The other end of resistor R7 is connected to one end of capacitor C31 and grounded. The other end of resistor R8 is connected to the other end of capacitor C31 and the negative terminal of Schottky diode D4 to form the second power supply voltage output terminal. The voltage regulator U5 includes the model TPS61170QDRVRQ1, which converts the power supply voltage VDD into a third power supply voltage (+15V).

[0036] Furthermore, the power supply module also includes a supplementary capacitor module, which includes capacitors C33, C34, C35, C36, C37, C38, C39, C40, C41, C42, resistors R23 and R24, indicator LED3, and indicator LED4. Please refer to Figure 8One end of capacitor C33 is connected to the second power supply voltage output terminal, and the other end of capacitor C33 is connected to the power supply ground. Capacitors C34, C35, C36, and C37 are connected in parallel with capacitor C33. The second power supply voltage output terminal is connected to the negative terminal of indicator LED4. The positive terminal of indicator LED4 is connected to the power supply ground through resistor R24. Indicator LED4 is used to indicate the output status of the second power supply voltage.

[0037] One end of capacitor C38 is connected to the third power supply voltage output terminal, and the other end of capacitor C38 is connected to the power supply ground. Capacitors C39, C40, C41, and C42 are connected in parallel with capacitor C38. The third power supply voltage output terminal is connected to the positive terminal of indicator LED3 through resistor R23. The negative terminal of indicator LED3 is connected to the power supply ground. Indicator LED3 is used to indicate the output status of the third power supply voltage.

[0038] In the description of this specification, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. The descriptions using terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment / mode or example, which are included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0039] The above descriptions are merely preferred embodiments of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and variations that can be directly derived or conceived by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included within the protection scope of the present invention.

Claims

1. A short-circuit protection circuit suitable for a half-bridge switching topology, characterized in that, The half-bridge switching topology includes a power supply, a busbar capacitor C1, a high-side switch Q1, and a low-side switch Q2. The short-circuit protection circuit includes a sampling resistor, a protection switch Q3, and a protection module. The second electrode of the high-side switch Q1 is connected to the first electrode of the low-side switch Q2. One end of the busbar capacitor C1 is connected to the second electrode of the low-side switch Q2 and the negative terminal of the power supply. The first electrode of the high-side switch Q1 is connected to the other end of the busbar capacitor C1 and the second electrode of the protection switch Q3 through a sampling resistor. The first electrode of the protection switch Q3 is connected to the positive terminal of the power supply. The protection module is connected to the sampling resistor and the third electrode of the protection switch Q3. The protection module is used to collect the voltage across the sampling resistor and control the protection switch Q3 to turn off when the voltage across the sampling resistor is greater than a preset protection threshold.

2. The short-circuit protection circuit suitable for a half-bridge switching topology according to claim 1, characterized in that, The protection module includes a driver chip U1, connectors H1 and H2, interface RF1, interface CN2, resistors R10, R18, R20, R34, R35, R36, R37, R38, and R39, and capacitors C18, C19, C47, and C48. The first pin of the interface CN2 is connected to one end of the sampling resistor and one end of the resistor R18. The second pin of the interface CN2 is connected to the other end of the sampling resistor and connected to the power supply ground. The other end of the resistor R18 is connected to the OC pin of the driver chip U1. The OC pin is also connected to the power supply ground through the capacitor C47. The fifth pin of the interface RF1 is connected to the third pin of the connector H2 and connected to the analog ground through resistor R39. The second pin of the connector H2 is connected to the third pin and the second pin of the connector H2 is connected to the IN+ pin of the driver chip U1. The first pin of the connector H2 is connected to the first power supply voltage through resistor R38.

3. The short-circuit protection circuit suitable for a half-bridge switching topology according to claim 2, characterized in that, The VCC pin of the driver chip U1 is connected to analog ground through resistor R10, capacitor C19, and capacitor C18, and is connected to the first power supply voltage; the IN+ pin of the driver chip U1 is connected to the GND pin through capacitor C48 and is connected to analog ground. The OUTL pin of the driver chip U1 is connected to one end of resistors R34 and R35, and the OUTH pin of the driver chip U1 is connected to one end of resistors R36 and R37. The other end of resistors R34, R35, R36, and R37 is connected to the CLMPI pin of the driver chip U1 and the first to sixth pins of connector H1, and connected to the power supply ground through resistor R20. The first to sixth pins of connector H1 are connected to the third electrode of the protection switch Q3, and the ninth to fourteenth pins of connector H1 are connected to the second electrode of the protection switch Q3 and connected to the power supply ground.

4. The short-circuit protection circuit suitable for a half-bridge switching topology according to claim 3, characterized in that, The protection module also includes resistors R11, R12, R13, R41, R42, capacitors C44, C45, and C46, ​​indicator lights LED5 and LED6. The VEE pin of the driver chip U1 is connected to a second power supply voltage, and the VDD pin of the driver chip U1 is connected to a third power supply voltage. The RDY pin of driver chip U1 is connected to the negative terminal of indicator LED5 and one end of resistor R11. The FLT pin of driver chip U1 is connected to the negative terminal of indicator LED6 and one end of resistor R12. The RST pin of driver chip U1 is connected to one end of resistor R13. The positive terminal of indicator LED5 is connected to one end of resistor R41. The positive terminal of indicator LED6 is connected to one end of resistor R42. The other ends of resistors R11, R12, R13, R41, and R42 are connected to the first power supply voltage. The RDY pin is connected to analog ground through capacitor C46. The FLT pin is connected to analog ground through capacitor C45. The RST pin is connected to analog ground through capacitor C44.

5. The short-circuit protection circuit suitable for a half-bridge switching topology according to claim 4, characterized in that, It also includes a power module, which includes a power input module; The power input module includes an interface CN1, a fuse F2, a Schottky diode D3, a common-mode filter L2, an inductor L1, a capacitor C13, a capacitor C14, a resistor R21, and an indicator LED1. The first pin of interface CN1 is connected to the input power supply and one end of fuse F2. The other end of fuse F2 is connected to the negative terminal of Schottky diode D3, one end of capacitor C12, and the fourth pin of common-mode filter L2. The positive terminal of Schottky diode D3 is connected to the other end of capacitor C12 and the first pin of common-mode filter L2 and grounded. The third pin of common-mode filter L2 is connected to one end of capacitor C13 and one end of inductor L1. The second pin of common-mode filter L2 is connected to the other end of capacitor C13 and one end of capacitor C14 and grounded. The other end of inductor L1 is connected to the other end of capacitor C14 to form the output terminal of the power input module. The output terminal of the power input module is connected to one end of resistor R21. The other end of resistor R21 is connected to the positive terminal of indicator LED1. The negative terminal of indicator LED1 is grounded.

6. The short-circuit protection circuit suitable for a half-bridge switching topology according to claim 5, characterized in that, The power module further includes a first output module, which is used to output a first power supply voltage. The first output module includes a voltage regulator U2, a voltage regulator U6, a capacitor C15, a capacitor C16, a capacitor C19, a resistor R22, and an indicator LED2. The input terminal of the voltage regulator U2 is connected to the output terminal of the power input module. The ground terminal of the voltage regulator U2 is grounded. The positive output terminal of the voltage regulator U2 is connected to the negative output terminal of the voltage regulator U2 through capacitor C19, and the negative output terminal of the voltage regulator U2 is connected to analog ground. The input terminal of voltage regulator U6 is connected to the positive output terminal of voltage regulator U2, and is connected to the ground terminal of voltage regulator U6 through capacitor C16. The ground terminal of voltage regulator U6 is connected to analog ground. The output terminal of voltage regulator U6 is connected to analog ground through capacitor C15. The input terminal of voltage regulator U6 is connected to the positive terminal of indicator LED2 through resistor R22. The negative terminal of indicator LED2 is connected to analog ground.

7. The short-circuit protection circuit suitable for a half-bridge switching topology according to claim 5, characterized in that, The power module also includes a conversion module, which includes a voltage regulator U3, a Schottky diode D5, an inductor L3, an inductor L4, a capacitor C20, a capacitor C21, a capacitor C22, and a capacitor C23. The output terminal of the power input module is connected to the positive terminal of Schottky diode D5, the negative terminal of Schottky diode D5 is connected to the input terminal of voltage regulator U3, the ground terminal of voltage regulator U3 is grounded, the positive output terminal of voltage regulator U3 is connected to one end of inductor L3 and one end of capacitor C20, the other end of inductor L3 is connected to one end of capacitor C21, the other end of capacitor C20 is connected to the other end of capacitor C21, one end of capacitor C23 and one end of capacitor C22, the negative output terminal of voltage regulator U3 is connected to the other end of capacitor C23 and one end of inductor L4, and the other end of inductor L4 is connected to the other end of capacitor C22.

8. The short-circuit protection circuit suitable for a half-bridge switching topology according to claim 5, characterized in that, The power module also includes a second output module, which is used to output a second power supply voltage. The second output module includes a voltage regulator U4, resistors R3, R4, R5, R6, capacitors C24, C25, and C27. The IN pin of voltage regulator U4 is connected to the other end of inductor L3. The IN pin of voltage regulator U4 is also connected to power ground through capacitor C24. Capacitor C25 is connected in parallel with capacitor C24. The IN pin of voltage regulator U4 is connected to one end of resistor R3. The other end of resistor R3 is connected to the EN pin of voltage regulator U4 and one end of resistor R4. The other end of resistor R4 is connected to power ground. The OUT pin of voltage regulator U4 is connected to one end of resistor R6 and one end of capacitor C27, forming a second power supply voltage output terminal. The other end of resistor R6 is connected to one end of resistor R5 and the FB pin of voltage regulator U4. The other end of resistor R5 is connected to the other end of capacitor C27 and connected to power ground.

9. The short-circuit protection circuit suitable for a half-bridge switching topology according to claim 8, characterized in that, The power module also includes a third output module, which is used to output a third power supply voltage. The third output module includes a voltage regulator U5, capacitors C30, C31, C32, and C43, an inductor L5, resistors R7, R8, and R9, and a Schottky diode D4. One end of inductor L5 is connected to the other end of inductor L4. One end of inductor L5 is connected to power ground through capacitor C43. Capacitor C30 is connected in parallel with capacitor C43. The other end of inductor L5 is connected to the positive terminal of Schottky diode D4 and the SW pin of voltage regulator U5. One end of inductor L5 is also connected to the CTRL pin and VIN pin of voltage regulator U5. The GND pin of voltage regulator U5 is grounded. The COMP pin of voltage regulator U5 is connected to one end of capacitor C32 through resistor R9. The other end of capacitor C32 is grounded. The FB pin of voltage regulator U5 is connected to one end of resistor R7 and resistor R8. The other end of resistor R7 is connected to one end of capacitor C31 and grounded. The other end of resistor R8 is connected to the other end of capacitor C31 and the negative terminal of Schottky diode D4 to form the second power supply voltage output terminal.

10. The short-circuit protection circuit suitable for a half-bridge switching topology according to claim 9, characterized in that, The power module also includes a supplementary capacitor module, which includes capacitors C33, C34, C35, C36, C37, C38, C39, C40, C41, C42, resistors R23 and R24, indicator LED3 and indicator LED4. One end of capacitor C33 is connected to the second power supply voltage output terminal, and the other end of capacitor C33 is connected to the power supply ground. Capacitors C34, C35, C36, and C37 are connected in parallel with capacitor C33. The second power supply voltage output terminal is connected to the negative terminal of indicator LED4, and the positive terminal of indicator LED4 is connected to the power supply ground through resistor R24. One end of capacitor C38 is connected to the third power supply voltage output terminal, and the other end of capacitor C38 is connected to the power supply ground. Capacitors C39, C40, C41, and C42 are connected in parallel with capacitor C38. The third power supply voltage output terminal is connected to the positive terminal of indicator LED3 through resistor R23, and the negative terminal of indicator LED3 is connected to the power supply ground.

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