A switching power supply based on SiC-MOS tube driving
By introducing resistor R1, parallel transistors Q1 and Q2, and overvoltage protection circuit into the SiC-MOS transistor drive power supply, the problems of LC oscillation and power supply voltage fluctuation are solved, realizing a switching power supply design with fast turn-on, anti-interference and high reliability, and reducing the system failure rate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHANGZHOU CHENGLIAN POWER SUPPLY MFG
- Filing Date
- 2025-06-23
- Publication Date
- 2026-06-26
AI Technical Summary
Existing switching power supplies based on SiC-MOS transistors fail to effectively consider the impact of parasitic inductance and capacitance on LC oscillations, core saturation, and power supply voltage fluctuations, leading to problems such as equipment damage or data loss.
Resistor R1 is used to suppress the parasitic inductance on the PCB board and the LC oscillation formed by capacitor C1. Transistors Q1 and Q2 are connected in parallel to improve the current supply capability. Overvoltage protection circuit is added to limit excessive voltage. Transformer T is used to drive the MOSFET to achieve electrical isolation and signal transmission efficiency. Combined with capacitor banks one and two, the conduction speed and anti-interference capability of SiC-MOSFET are improved.
It effectively prevents LC oscillation and core saturation, improves the conduction speed of SiC-MOS transistors, reduces high-frequency oscillation, lowers the system failure rate, ensures that SiC-MOS transistors operate within a safe voltage range, and prevents equipment damage and data loss.
Smart Images
Figure CN224418676U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a switching power supply based on SiC-MOS transistor driving, and particularly to a switching power supply based on SiC-MOS transistor driving, belonging to the field of SiC-MOS transistor driving technology. Background Technology
[0002] SiC-MOS transistors combine the high temperature and high frequency advantages of silicon carbide (SiC) materials with the low loss characteristics of metal oxide semiconductor field-effect transistors (MOSFETs), giving them significant advantages in switching power supplies.
[0003] When designing switching power supplies or motor drive circuits using MOSFETs, most people consider the MOSFET's on-resistance, maximum voltage, and maximum current. Many people only consider these factors. Such a circuit may work, but it is not excellent.
[0004] Therefore, it is urgent to improve the switching power supply based on SiC-MOS transistor drive to solve the above-mentioned problems. Utility Model Content
[0005] The purpose of this invention is to provide a switching power supply based on SiC-MOS transistor drive. Resistor R1 can suppress the LC oscillation formed by the parasitic inductance and capacitor C1 on the PCB board, thereby isolating DC and allowing AC to pass through. It can also prevent the magnetic core from saturating. The parallel transistor Q1 and transistor Q2 drive circuit is used to improve the current supply capability and quickly complete the charging process of the gate input capacitor. This topology increases the time required for conduction but reduces the turn-off time. The switching transistor can be turned on quickly and avoid high-frequency oscillation on the rising edge.
[0006] To achieve the above objectives, the main technical solutions adopted by this utility model include:
[0007] A switching power supply based on SiC-MOS transistor driving includes two SiC-MOS transistors arranged in parallel, and the two SiC-MOS transistors are electrically connected to a power supply IC through a transformer T.
[0008] A resistor R1 and a capacitor C1 are connected in series between the transformer T and the power supply IC. A diode D1 and a resistor R2 are connected in parallel with the resistor R1. The diode D1 and the resistor R2 are connected in series.
[0009] The VCC terminals of the two SiC-MOS transistors are electrically connected to the collector power supply voltage.
[0010] Preferably, one end of the transformer T near the power supply IC is electrically connected to the capacitor C1, and the other end is fed back to the power supply IC.
[0011] Preferably, transistors Q1 and Q2 are connected in parallel between the power supply IC and the resistor R1.
[0012] Preferably, resistors R3 and R4 are connected in parallel on the gate G of the SiC-MOS transistor and electrically connected to the transformer T;
[0013] A resistor R5 and a resistor R6 are connected in parallel on the gate G of the SiC-MOS transistor described below and are electrically connected to the transformer T.
[0014] Preferably, a capacitor bank one is provided on the SiC-MOS transistor mentioned above, and the capacitor bank one includes capacitor C1, capacitor C2 and capacitor C2;
[0015] The SiC-MOS transistor described below is provided with a second capacitor group, which includes capacitors C5, C6 and C7.
[0016] Preferably, an overvoltage protection circuit is electrically connected between the power supply IC and the resistor R1. The overvoltage protection circuit includes a transistor Q3 and a PMOS transistor Q4 that are electrically connected. Resistors R7 and R8 are electrically connected to the base B of the transistor Q3. The emitter of the transistor Q3 is electrically connected to the source S of the PMOS transistor Q4 and connected to Vin. Resistors R7 and R8 are connected in parallel and then grounded through diode D2.
[0017] Preferably, a resistor R9 is electrically connected between the gate G and source S of the PMOS transistor Q4, and is electrically connected to the collector C of the transistor Q3.
[0018] Preferably, a resistor R10 is electrically connected between the gate G of the PMOS transistor Q4 and the ground of the diode D2.
[0019] This utility model has at least the following beneficial effects:
[0020] 1. Resistor R1 can suppress the LC oscillation formed by the parasitic inductance and capacitor C1 on the PCB board, thus isolating DC and allowing AC to pass through. It can also prevent the magnetic core from saturating. The parallel transistors Q1 and Q2 drive circuit is used to improve the current supply capability and quickly complete the charging process of the gate input capacitor. This topology increases the time required for conduction but reduces the turn-off time. The switching transistors can be turned on quickly and avoid high-frequency oscillations on the rising edge.
[0021] 2. When the power supply voltage rises abnormally, the overvoltage circuit can respond quickly and limit the excessive voltage to a safe range, thereby preventing the SiC-MOS transistor from being damaged due to excessive voltage. By adding an overvoltage protection circuit, the system failure rate caused by power supply voltage fluctuations can be effectively reduced, ensuring that the SiC-MOS transistor operates within a safe voltage range, thereby preventing equipment damage or data loss due to malfunctions. Attached Figure Description
[0022] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:
[0023] Figure 1 This is the circuit diagram of this utility model;
[0024] Figure 2 This is the overvoltage protection circuit diagram of this utility model. Detailed Implementation
[0025] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.
[0026] like Figures 1-2 As shown, the switching power supply based on SiC-MOS transistor driving provided in this embodiment includes two SiC-MOS transistors connected in parallel. The two SiC-MOS transistors are electrically connected to a power supply IC through a transformer T. One end of the coil of the transformer T near the power supply IC is electrically connected to a capacitor C1, and the other end is fed back to the power supply IC. Resistors R3 and R4 are connected in parallel on the gate G of the upper SiC-MOS transistor and are electrically connected to the transformer T. Resistors R5 and R6 are connected in parallel on the gate G of the lower SiC-MOS transistor and are electrically connected to the transformer T. In order to meet the driving requirements of the MOS transistors, transformer T is used for driving. Using transformer T to drive the MOS transistors has advantages such as electrical isolation, flexible voltage matching, high signal transmission efficiency, strong anti-interference ability, and suitability for special scenarios. These advantages make the transformer driving scheme widely used in power electronic systems that require high safety, high efficiency, and high reliability.
[0027] A resistor R1 and a capacitor C1 are connected in series between the transformer T and the power IC. A diode D1 and a resistor R2 are connected in parallel with the resistor R1. The diode D1 and the resistor R2 are connected in series. The purpose of the resistor R1 is to suppress the LC oscillation formed by the parasitic inductance on the PCB board and the capacitor C1. The purpose of the capacitor C1 is to block DC and allow AC to pass through, while also preventing the magnetic core from saturating.
[0028] The VCC terminals of the two SiC-MOS transistors are electrically connected to the collector power supply voltage, resulting in a simple structure and significantly reducing production costs.
[0029] Meanwhile, transistors Q1 and Q2 are connected in parallel between the power IC and resistor R1. If the parasitic capacitance of the selected SiC-MOS transistor is relatively large and the driving capability inside the power IC is insufficient, the driving capability needs to be enhanced in the driving circuit. Totem pole circuits are often used to increase the driving capability of the power IC. The function of the parallel transistors Q1 and Q2 driving circuit is to improve the current supply capability and quickly complete the charging process of the gate input capacitor. This topology increases the time required for conduction but reduces the turn-off time. The switching transistors can be turned on quickly and avoid high-frequency oscillations on the rising edge.
[0030] Additionally, a capacitor bank one is located on the upper SiC-MOS transistor, consisting of capacitors C1, C2, and C3. A capacitor bank two is located on the lower SiC-MOS transistor, consisting of capacitors C5, C6, and C7. If the values of capacitors C1, C2, C5, and C6 are relatively large, the energy required for the SiC-MOS transistor to turn on will be relatively large. If the power supply IC does not have a large peak drive current, the SiC-MOS transistor will turn on relatively slowly. If the drive capability is insufficient, high-frequency oscillations may occur on the rising edge. Even if the resistor R1 is reduced, it cannot solve the problems of the power supply IC's drive capability, the size of the parasitic capacitance of the SiC-MOS transistor, and the switching speed of the SiC-MOS transistor. All these factors affect the selection of the drive resistor value, so the resistor R1 cannot be reduced indefinitely.
[0031] Furthermore, such as Figure 2 As shown, an overvoltage protection circuit is electrically connected between the power supply IC and resistor R1. The overvoltage protection circuit includes a transistor Q3 and a PMOS transistor Q4 that are electrically connected. Resistors R7 and R8 are electrically connected to the base B of transistor Q3. The emitter of transistor Q3 is electrically connected to the source S of PMOS transistor Q4 and connected to Vin. Resistors R7 and R8 are connected in parallel and grounded through diode D2. When the power supply voltage rises abnormally, the overvoltage circuit can respond quickly and limit the excessive voltage to a safe range, thereby preventing the SiC-MOS transistor from being damaged due to excessive voltage. By adding an overvoltage protection circuit, the system failure rate caused by power supply voltage fluctuations can be effectively reduced, and the SiC-MOS transistor can be ensured to operate within a safe voltage range, thereby preventing equipment damage or data loss caused by malfunction.
[0032] A resistor R9 is electrically connected between the gate (G) and source (S) of PMOS transistor Q4, and is also electrically connected to the collector (C) of transistor Q3. A resistor R10 is electrically connected between the gate (G) of PMOS transistor Q4 and the ground of diode D2. When Vin is at a normal input voltage, transistor Q3 does not break down in reverse, the current through resistors R7 and R8 is essentially zero, and transistor Q3 is not conducting. The voltage Vgs of PMOS transistor Q4 is determined by the voltage division through resistors R9 and R10, and PMOS transistor Q4 is conducting, meaning the power supply is working normally.
[0033] When the input Vin is greater than the normal input voltage, Vin>Vbr, the Zener diode breaks down, and its voltage is Vbr. Transistor Q3 turns on, VCE≈0, that is, Vgs≈0 for PMOS transistor Q4, PMOS transistor Q4 does not turn on, the circuit is open, and overvoltage protection is achieved.
[0034] like Figures 1-2 As shown, the principle of the switching power supply based on SiC-MOS transistor driving provided in this embodiment is as follows:
[0035] To drive MOSFETs, transformer T is used. Transformer T-driven MOSFETs have advantages such as electrical isolation, flexible voltage matching, high signal transmission efficiency, strong anti-interference ability, and suitability for special scenarios. These advantages make transformer drive solutions widely used in power electronic systems that require high safety, high efficiency, and high reliability.
[0036] A resistor R1 and a capacitor C1 are connected in series between the transformer T and the power IC. A diode D1 and a resistor R2 are connected in parallel with the resistor R1. The diode D1 and the resistor R2 are connected in series. The purpose of the resistor R1 is to suppress the LC oscillation formed by the parasitic inductance on the PCB board and the capacitor C1. The purpose of the capacitor C1 is to block DC and allow AC to pass through, while also preventing the magnetic core from saturating.
[0037] The VCC terminals of the two SiC-MOS transistors are electrically connected to the collector power supply voltage, resulting in a simple structure and significantly reducing production costs.
[0038] Meanwhile, transistors Q1 and Q2 are connected in parallel between the power supply IC and resistor R1. If the parasitic capacitance of the selected SiC-MOS transistor is relatively large and the internal driving capability of the power supply IC is insufficient, the driving capability needs to be enhanced in the driving circuit. Totem pole circuits are often used to increase the driving capability of the power supply IC. The function of the parallel transistors Q1 and Q2 driving circuit is to improve the current supply capability and quickly complete the charging process of the gate input capacitor. This topology increases the time required for conduction but reduces the turn-off time. The switching transistors can be turned on quickly and avoid high-frequency oscillations on the rising edge.
[0039] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" as used throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.
[0040] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes that element.
[0041] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.
Claims
1. A switching power supply based on SiC-MOS transistor driving, comprising two SiC-MOS transistors connected in parallel, characterized in that, The two parallel SiC-MOS transistors are electrically connected to a power supply IC via a transformer T; A resistor R1 and a capacitor C1 are connected in series between the transformer T and the power supply IC. A diode D1 and a resistor R2 are connected in parallel with the resistor R1. The diode D1 and the resistor R2 are connected in series. The VCC terminals of the two SiC-MOS transistors are electrically connected to the collector power supply voltage.
2. The switching power supply based on SiC-MOS transistor driving according to claim 1, characterized in that: One end of the transformer T, near the power supply IC, is electrically connected to the capacitor C1, while the other end is fed back to the power supply IC.
3. A switching power supply based on SiC-MOS transistor driving according to claim 1, characterized in that: Transistor Q1 and transistor Q2 are connected in parallel between the power supply IC and the resistor R1.
4. A switching power supply based on SiC-MOS transistor driving according to claim 1, characterized in that: Resistors R3 and R4 are connected in parallel on the gate G of the SiC-MOS transistor mentioned above and are electrically connected to the transformer T. A resistor R5 and a resistor R6 are connected in parallel on the gate G of the SiC-MOS transistor described below and are electrically connected to the transformer T.
5. A switching power supply based on SiC-MOS transistor driving according to claim 1, characterized in that: A capacitor bank is provided on the SiC-MOS transistor mentioned above. The capacitor bank includes capacitor C1, capacitor C2 and capacitor C2. The SiC-MOS transistor described below is provided with a second capacitor group, which includes capacitors C5, C6 and C7.
6. A switching power supply based on SiC-MOS transistor driving according to claim 1, characterized in that: An overvoltage protection circuit is electrically connected between the power supply IC and the resistor R1. The overvoltage protection circuit includes a transistor Q3 and a PMOS transistor Q4 that are electrically connected. Resistors R7 and R8 are electrically connected to the base B of the transistor Q3. The emitter of the transistor Q3 is electrically connected to the source S of the PMOS transistor Q4 and connected to Vin. Resistors R7 and R8 are connected in parallel and then grounded through diode D2.
7. A switching power supply based on SiC-MOS transistor driving according to claim 6, characterized in that: The gate G and source S of the PMOS transistor Q4 are electrically connected by a resistor R9, and are also electrically connected to the collector C of the transistor Q3.
8. A switching power supply based on SiC-MOS transistor driving according to claim 6, characterized in that: A resistor R10 is electrically connected between the gate G of the PMOS transistor Q4 and the ground of the diode D2.