A SiC MOSFET drive power supply circuit
By coordinating the design of the drive module, transformer rectification module and voltage regulator module, the problem of false turn-on caused by crosstalk in SiC MOSFETs under high voltage and high switching speed is solved, realizing stable power supply and safe operation of SiC MOSFETs. The circuit structure is simple and low cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI FENGTIAN ELECTRONICS
- Filing Date
- 2025-07-07
- Publication Date
- 2026-06-05
AI Technical Summary
In high-voltage and high-switching-rate applications, SiC MOSFETs are prone to false turn-on due to crosstalk, which may cause shoot-through of the upper and lower bridge arms, resulting in system short circuit damage.
The SiC MOSFET driver power supply circuit adopts a collaborative design of a drive module, a transformer and rectifier module, a voltage regulator module, and a negative voltage module. It includes a control chip, an RC filter circuit, a clamping diode, a DC blocking capacitor, a current limiting resistor, a transformer, a rectifier diode, and a Zener diode. Through RC filtering, clamping protection, transformer rectification, and voltage regulation biasing, it ensures a stable power supply to the SiC MOSFET.
It effectively prevents bridge arm erroneous turn-on, ensuring the safe and reliable operation of SiC MOSFETs in high-voltage, high-switching-rate environments. The circuit structure is simple, low-cost, and suitable for multi-SiC MOSFET scenarios, reducing the power supply loop size.
Smart Images
Figure CN224329381U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of power electronics technology, specifically relating to a SiC MOSFET drive power supply circuit, particularly for driving power supply of SiC MOSFETs in automotive OBC products, PFC modules, or DC-DC converters. Background Technology
[0002] As the demand for higher power density in OBC products increases, ordinary Si MOSFETs are gradually becoming insufficient to meet product size requirements. Due to the advantages of silicon carbide (SiC) MOSFETs, such as high-frequency switching, low reverse recovery, and low on-resistance, they can significantly improve system efficiency and power density, and are already being used in large quantities in current small-volume OBC products.
[0003] Since SiC MOSFETs are primarily used in OBC systems for high-voltage and high-switching applications, their dV / dt during switching is significantly higher than that of ordinary Si MOSFETs. In bridge circuits, when the upper MOSFET turns on quickly and the lower MOSFET turns off, the Vds of the lower MOSFET increases. At this time, charge is transferred to the gate of the lower MOSFET through the Miller capacitance Cgd, causing a small spike in the gate voltage. If the voltage rise caused by crosstalk during this process exceeds the turn-on threshold voltage of the SiC MOSFET, it may cause the lower bridge arm to turn on erroneously, leading to shoot-through between the upper and lower bridge arms and serious consequences such as short circuit damage to the system. Therefore, negative voltage drive is generally used to prevent the upper and lower MOSFETs from conducting to each other.
[0004] Therefore, a SiC MOSFET drive power supply circuit is needed to ensure the safe operation of the SiC MOSFET. Summary of the Invention
[0005] In view of the above-mentioned shortcomings in the prior art, this utility model provides a SiC MOSFET driving power supply circuit to solve the problem of SiC MOSFETs being falsely turned on due to crosstalk in high voltage and high switching speed application scenarios, and to ensure its safe and stable operation.
[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0007] A SiC MOSFET driving power supply circuit includes a driving module, a transformer-rectifier module, a voltage regulator module, and a negative voltage module. The driving module includes a control chip (MCU), an RC filter circuit, an input power supply filter capacitor, a driving chip (U1), a clamping diode, a DC blocking capacitor (C5), and a current-limiting resistor (R3). The RC filter circuit includes resistors R1 and R2, and capacitors C1 and C2. The input power supply filter capacitor includes capacitors C3 and C4. The clamping diode includes diodes D1, D2, D3, and D4. The transformer-rectifier module includes a transformer (T1), rectifier diodes, and a filter capacitor (C6). The rectifier diodes include diodes D5, D6, D7, and D8. The voltage regulator module includes a current-limiting resistor (R4), a bias resistor (R5), a transistor (Q1), a Zener diode (ZD1), and a filter capacitor (C7). The negative voltage module includes a current-limiting resistor (R6), a Zener diode (ZD2), and filter capacitors C8 and C9.
[0008] Furthermore, in the driver module, the MCU's PWM1 port is connected to the first port of R1, the second port of R1 is connected to the second port of C2 and PIN4 of the driver chip U1, the first port of C2 is connected to the power supply ground GND_P, the MCU's PWM2 port is connected to the first port of R2, the second port of R2 is connected to the second port of C1 and PIN2 of the driver chip U1, and the first port of C1 is connected to the power supply ground GND_P; PIN3 of the driver chip U1 is connected to the second ports of C3 and C4 and connected to the power supply ground GND_P, and PIN6 of the driver chip U1 is connected to the first ports of C3 and C4. Connect the power supply to the positive terminal V+_P. Connect the PIN5 of the driver chip U1 to the first port of R3 and the PIN7 of the driver chip U1 to the first port of C5. Connect the first port of D1 to the positive terminal V+_P of the power supply and the second port to the PIN5 of the driver chip U1. Connect the first port of D2 to the positive terminal V+_P of the power supply and the second port to the PIN7 of the driver chip U1. Connect the first port of D3 to the PIN5 of the driver chip U1 and the second port to the power supply ground GND_P. Connect the first port of D4 to the PIN7 of the driver chip U1 and the second port to the power supply ground GND_P.
[0009] Furthermore, in the transformer rectifier module, PIN1 of transformer T1 is connected to the second port of R3, and PIN3 is connected to the second port of C5; PIN5 is connected to the second port of D6 and the first port of D8; the other winding of transformer T1 is connected to the second port of D5 and the first port of D7; the first ports of D5 and D6 are connected to the first terminal of C6 and the first port of R4; the second ports of D7 and D8 are connected to the second port of C6 and connected to negative ground -3V.
[0010] Furthermore, in the voltage regulator module, the second port of R4 is connected to the second port of R5 and the collector (C) of Q1, the base (B) of Q1 is connected to the first port of R5 and the first port of ZD1, and the emitter (E) of Q1 is connected to the first port of C7; the second port of C7 and the second port of ZD1 are connected and connected to negative ground -3V.
[0011] Furthermore, in the negative voltage module, the first port of R6 is connected to the first ports of C7 and C8 and connected to +18V, and the second port is connected to the first port of ZD2 and connected to the drive power supply ground GND; the second port of ZD2 is connected to the second port of C9 and connected to the negative voltage ground -3V.
[0012] Preferably, the resistance of R1 and R2 is 100Ω, and the capacitance of C1 and C2 is 100pF.
[0013] Preferably, the driving frequency of the driver chip U1 is 200KHz-300KHz.
[0014] Preferably, the transformer T1 is model EE8.3, the Zener diode ZD1 has a Zener voltage regulation value of 18V or 15V, and the Zener diode ZD2 has a Zener voltage regulation value of -3V or -5V.
[0015] Compared with the prior art, this utility model has the following advantages:
[0016] Through the coordinated operation of the drive module, transformer and rectifier module, voltage regulator module and negative voltage module, a stable power supply to SiCMOSFET is achieved, effectively preventing bridge arm erroneous turn-on;
[0017] The circuit structure is simple, adopts discrete component design, has a lower cost than dedicated power supply chips, and is easy to lay out in multi-SiCMOSFET scenarios, reducing the power supply loop;
[0018] Each module has a clearly defined function. Through designs such as RC filtering, clamping protection, transformer rectification, voltage regulation, and negative voltage bias, the SiC MOSFET is guaranteed to operate safely and reliably in high-voltage and high-switching-rate environments. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the structure of a SiC MOSFET driving power supply circuit according to the present invention;
[0020] The reference numerals in the accompanying drawings include: 1. Drive module; 2. Transformer and rectifier module; 3. Voltage regulator module; 4. Negative voltage module. Detailed Implementation
[0021] To enable those skilled in the art to better understand this utility model, the technical solution of this utility model will be further described below in conjunction with the accompanying drawings and embodiments.
[0022] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this patent. To better illustrate the embodiments of this utility model, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.
[0023] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.
[0024] In the description of this utility model, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating the connection relationship between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Example
[0025] like Figure 1As shown, this utility model provides a SiC MOSFET driving power supply circuit, comprising a driving module 1, a transformer-rectifier module 2, a voltage regulator module 3, and a negative voltage module 4. The driving module 1 includes a control chip MCU, an RC filter circuit, an input power supply filter capacitor, a driving chip U1, a clamping diode, a DC blocking capacitor C5, and a current-limiting resistor R3. The RC filter circuit includes resistors R1 and R2, and capacitors C1 and C2. The input power supply filter capacitor includes capacitors C3 and C4. The clamping diode includes diodes D1, D2, D3, and D4. The transformer-rectifier module 2 includes a transformer T1, rectifier diodes, and a filter capacitor C6. The rectifier diodes include diodes D5, D6, D7, and D8. The voltage regulator module 3 includes a current-limiting resistor R4, a bias resistor R5, a transistor Q1, a Zener diode ZD1, and a filter capacitor C7. The negative voltage module 4 includes a current-limiting resistor R6, a Zener diode ZD2, and filter capacitors C8 and C9.
[0026] In this embodiment, in the driver module 1, the PWM1 port of the MCU is connected to the first port of R1, the second port of R1 is connected to the second port of C2 and PIN4 of the driver chip U1, the first port of C2 is connected to the power supply ground GND_P, the PWM2 port of the MCU is connected to the first port of R2, the second port of R2 is connected to the second port of C1 and PIN2 of the driver chip U1, and the first port of C1 is connected to the power supply ground GND_P; PIN3 of the driver chip U1 is connected to the second ports of C3 and C4 and connected to the power supply ground GND_P, and PIN6 of the driver chip U1 is connected to the first ports of C3 and C4. Connect the power supply to the positive terminal V+_P. Connect the PIN5 of the driver chip U1 to the first port of R3 and the PIN7 of the driver chip U1 to the first port of C5. Connect the first port of D1 to the positive terminal V+_P of the power supply and the second port to the PIN5 of the driver chip U1. Connect the first port of D2 to the positive terminal V+_P of the power supply and the second port to the PIN7 of the driver chip U1. Connect the first port of D3 to the PIN5 of the driver chip U1 and the second port to the power supply ground GND_P. Connect the first port of D4 to the PIN7 of the driver chip U1 and the second port to the power supply ground GND_P.
[0027] In this embodiment, in the transformer rectifier module 2, PIN1 of transformer T1 is connected to the second port of R3, and PIN3 is connected to the second port of C5; PIN5 is connected to the second port of D6 and the first port of D8; the other winding of transformer T1 is connected to the second port of D5 and the first port of D7; the first ports of D5 and D6 are connected to the first terminal of C6 and the first port of R4; the second ports of D7 and D8 are connected to the second port of C6 and connected to negative ground -3V.
[0028] In this embodiment, in the voltage regulator module 3, the second port of R4 is connected to the second port of R5 and the collector (C) of Q1, the base (B) of Q1 is connected to the first port of R5 and the first port of ZD1, and the emitter (E) of Q1 is connected to the first port of C7; the second port of C7 and the second port of ZD1 are connected and connected to negative ground -3V.
[0029] In this embodiment, in the negative pressure module 4, the first port of R6 is connected to the first ports of C7 and C8 and connected to +18V, and the second port is connected to the first port of ZD2 and connected to the drive power supply ground GND; the second port of ZD2 is connected to the second port of C9 and connected to the negative pressure ground -3V.
[0030] Principle: In drive module 1, the MCU provides the PWM drive signal, with a recommended drive frequency of 200kHz-300kHz to reduce the size of the transformer. In the RC filter circuit, R1, R2, C1, and C2 are responsible for filtering out interference signals in the PWM signal, ensuring the drive signal is not interfered with in harsh working environments. The preferred resistance values for R1 and R2 are 100Ω, and for C1 and C2 are 100pF. Driven by the PWM, the driver chip U1 is responsible for chopping the DC power supply of V+_P into an AC square wave. Filter capacitors C3 and C4 are responsible for filtering out voltage fluctuations and interference in V+_P. D1, D2, D3, and D4 perform voltage clamping to protect pins 5 and 7 of the driver chip U1. The pins are not damaged by positive or negative high voltage; resistor R3 limits the current flowing through the driver chip U1 and transformer T1; C5 is a DC blocking capacitor to prevent transformer T1 from becoming magnetized and saturating; the transformer is responsible for voltage transformation, preferably EE8.3, and the turns ratio is selected according to the ratio of input voltage to output voltage; D5, D6, D7, and D8 are rectifier diodes that rectify the transformed AC into pulsating DC; the filter capacitor filters the pulsating DC into stable DC. Since the front-end driver module and transformer module operate in open loop, the voltage across C6 will change with the voltage of V+_P. Since the SiC_MOS requires a relatively stable driving voltage, back-end voltage regulation is required.
[0031] In voltage regulator module 3, resistor R4 limits the current flowing through Q1, and resistor R5 is a bias resistor to prevent Q1 from turning on accidentally. Zener diode ZD1 provides the target voltage for voltage regulator module 3; the target output voltage is the Zener diode's regulated voltage VZD1 - Vbe_Q1. Q1 is an amplifier diode, controlled by ZD1, continuously adjusting the voltage Vce to stabilize the output voltage of the voltage regulator module to the target value. Vc7 = VZD1 - Vbe_Q1 = Vc6 - VCE_Q1. C7 filters out interference in the circuit and stabilizes the output voltage. Zener diode ZD1 is preferably 18V or 15V depending on the positive drive voltage requirement of different SiC_MOS transistors.
[0032] In the negative voltage module, R6 is a current-limiting resistor to prevent large currents from flowing through ZD2. Zener diode ZD2 is biased by a negative voltage. Filter capacitors C8 and C9 filter out fluctuations in the output positive and negative voltages. The Zener diode ZD2 is preferably -3V or -5V, depending on the driving negative voltage requirements of different SiC_MOS transistors.
[0033] This invention provides a SiCMOSFET drive power supply circuit that can be used to power the power transistors of products in various fields. It is a beneficial improvement to existing new energy vehicle electronic products and has very important practical significance for promotion.
[0034] The above are merely embodiments of this utility model. The circuits, electronic components, and modules involved are all prior art, fully achievable by those skilled in the art, and require no further explanation. The content protected by this application does not involve improvements to the software or methods. Commonly known structures and characteristics in the solution are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field to which this utility model pertains prior to the application date or priority date, are able to access all existing technologies in that field, and possess the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in conjunction with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this utility model. These should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent.
Claims
1. A SiC MOSFET driving power supply circuit, characterized in that: It includes a drive module (1), a transformer rectifier module (2), a voltage regulator module (3), and a negative voltage module (4); The drive module (1) includes a control chip MCU, an RC filter circuit, an input power supply filter capacitor, a drive chip U1, a clamping diode, a DC blocking capacitor C5, and a current limiting resistor R3. The RC filter circuit includes resistors R1 and R2, and capacitors C1 and C2. The input power supply filter capacitor includes capacitors C3 and C4. The clamping diode includes diodes D1, D2, D3, and D4. The transformer rectifier module (2) includes a transformer T1, rectifier diodes, and filter capacitor C6. The rectifier diodes include diodes D5, D6, D7, and D8. The voltage regulator module (3) includes a current-limiting resistor R4, a bias resistor R5, a transistor Q1, a Zener diode ZD1, and a filter capacitor C7. The negative pressure module (4) includes a current-limiting resistor R6, a Zener diode ZD2, a filter capacitor C8, and a filter capacitor C9.
2. The SiC MOSFET driving power supply circuit as described in claim 1, characterized in that: In the driving module (1), the PWM1 port of the MCU is connected to the first port of R1, the second port of R1 is connected to the second port of C2 and PIN4 of the driving chip U1, the first port of C2 is connected to the power supply ground GND_P, the PWM2 port of the MCU is connected to the first port of R2, the second port of R2 is connected to the second port of C1 and PIN2 of the driving chip U1, and the first port of C1 is connected to the power supply ground GND_P; the PIN3 pin of the driving chip U1 is connected to the second ports of C3 and C4 and connected to the power supply ground GND_P, and the PIN6 pin of the driving chip U1 is connected to the first ports of C3 and C4. Connect the power supply to the positive terminal V+_P. Connect the PIN5 of the driver chip U1 to the first port of R3 and the PIN7 of the driver chip U1 to the first port of C5. Connect the first port of D1 to the positive terminal V+_P of the power supply and the second port to the PIN5 of the driver chip U1. Connect the first port of D2 to the positive terminal V+_P of the power supply and the second port to the PIN7 of the driver chip U1. Connect the first port of D3 to the PIN5 of the driver chip U1 and the second port to the power supply ground GND_P. Connect the first port of D4 to the PIN7 of the driver chip U1 and the second port to the power supply ground GND_P.
3. The SiC MOSFET driving power supply circuit as described in claim 2, characterized in that: In the transformer rectifier module (2), PIN1 of transformer T1 is connected to the second port of R3, and PIN3 is connected to the second port of C5; PIN5 is connected to the second port of D6 and the first port of D8; the other winding of transformer T1 is connected to the second port of D5 and the first port of D7; the first ports of D5 and D6 are connected to the first terminal of C6 and the first port of R4; the second ports of D7 and D8 are connected to the second port of C6 and connected to negative ground -3V.
4. The SiC MOSFET driving power supply circuit as described in claim 3, characterized in that: In the voltage regulator module (3), the second port of R4 is connected to the second port of R5 and the collector of Q1, the base of Q1 is connected to the first port of R5 and the first port of ZD1, and the emitter of Q1 is connected to the first port of C7; the second port of C7 and the second port of ZD1 are connected and connected to the negative ground -3V.
5. A SiC MOSFET driving power supply circuit as described in claim 4, characterized in that: In the negative voltage module (4), the first port of R6 is connected to the first port of C7 and the first port of C8 and connected to +18V, the second port is connected to the first port of ZD2 and connected to the drive power supply ground GND; the second port of ZD2 is connected to the second port of C9 and connected to the negative voltage ground -3V.
6. The SiC MOSFET driving power supply circuit as described in claim 5, characterized in that: The resistance values of R1 and R2 are 100Ω, and the capacitance values of C1 and C2 are 100pF.
7. A SiC MOSFET driving power supply circuit as described in claim 6, characterized in that: The driving frequency of the driver chip U1 is 200KHz-300KHz.
8. The SiC MOSFET driving power supply circuit as described in claim 7, characterized in that: The transformer T1 is model EE8.3, the voltage regulation value of the Zener diode ZD1 is 18V or 15V, and the voltage regulation value of the Zener diode ZD2 is -3V or -5V.