In-phase driving level conversion circuit with zero starting power consumption

Abstract

The invention provides an in-phase driving level conversion circuit with zero starting power consumption, which comprises a silicon carbide field effect transistor, a two-stage level inversion circuit used for controlling level inversion and connected to the silicon carbide field effect transistor, and a driving current amplification circuit used for driving the silicon carbide field effect transistor and connected to the two-stage level inversion circuit, the positive electrode of the circuit is connected to the driving current amplifying circuit; the two-stage level inversion circuit comprises a first field effect transistor and a second field effect transistor, the drain electrode of the first field effect transistor is connected with the grid electrode of the second field effect transistor, and the source electrode of the first field effect transistor and the source electrode of the second field effect transistor are jointly connected to the negative electrode of the circuit. The drain electrode of the second field effect transistor is connected to the grid electrode of the silicon carbide field effect transistor, and the source electrode of the second field effect transistor is connected with the source electrode of the silicon carbide field effect transistor; according to the invention, the level conversion function is ensured, and the standby energy consumption with zero power consumption is realized.

Description

Technical Field

[0001] The present invention relates to the field of drive circuits, and more particularly to a in-phase drive level conversion circuit with zero startup power consumption. Background Art

[0002] Silicon carbide has inherent advantages in the field of high-voltage technology. With the development of new energy technologies, the application scenarios of silicon carbide are becoming more and more extensive. The application of high-voltage silicon carbide reduces the technical difficulty of the design of high-voltage products. For example, in the application scenario of AC600V, after calculating the voltage fluctuation, the rectified voltage reaches 950V. It is undoubtedly difficult to design a stable and reliable auxiliary power supply at this voltage. However, high-voltage silicon carbide devices provide excellent alternative solutions. The mosfet with a breakdown voltage of 1700V provides a safe design margin for the auxiliary power supply. Together with an offline controller, a reliable auxiliary power supply can be designed.

[0003] However, the drive voltage of a conventional offline controller is generally 8V - 10V, while the drive voltage requirement of silicon carbide is 15 - 18V. Therefore, an intermediate level conversion circuit is needed. Although there are chips that can perform level conversion, the standby power consumption of the chips is basically greater than 300uA, which brings great design difficulties to the design of the startup circuit of the offline controller. Summary of the Invention

[0004] The purpose of the present invention is to provide a in-phase drive level conversion circuit that not only ensures the level conversion function but also realizes zero standby power consumption and zero startup power consumption.

[0005] To solve the above technical problems, the present invention provides a in-phase drive level conversion circuit with zero startup power consumption, including a silicon carbide field effect transistor, a two-stage level inversion circuit for controlling level inversion and connected to the silicon carbide field effect transistor, and a drive current amplification circuit for driving the silicon carbide field effect transistor and connected to the two-stage level inversion circuit. The positive pole of the circuit is connected to the drive current amplification circuit; the two-stage level inversion circuit includes a first field effect transistor and a second field effect transistor. The drain of the first field effect transistor is connected to the gate of the second field effect transistor. The source of the first field effect transistor and the source of the second field effect transistor are commonly connected to the negative pole of the circuit, and the drain of the second field effect transistor is connected to the gate of the silicon carbide field effect transistor. The source of the second field effect transistor is connected to the source of the silicon carbide field effect transistor, so that when the first field effect transistor is turned off and the second field effect transistor is turned on, the silicon carbide field effect transistor is in the cut-off state, and when the first field effect transistor is turned on and the second field effect transistor is turned off, the silicon carbide field effect transistor is in the conduction state.

[0006] Further, the drive current amplification circuit includes a first triode. The base of the first triode is connected to the drain of the first field effect transistor through a fourth resistor. The collector of the first triode is connected to the gate of the silicon carbide field effect transistor through a fifth resistor. And a second resistor is provided between the base and the emitter of the first triode, so that when the first field effect transistor is turned on and the second field effect transistor is turned off, the second resistor and the fourth resistor apply a voltage and turn on the first triode.

[0007] Further, it further includes a fast turn-off circuit. The fast turn-off circuit includes a second triode. The collector of the second triode is connected to the base of the first triode. The emitter of the second triode is connected to the positive pole of the circuit. And the base of the second triode is connected to the gate of the first field effect transistor and the offline controller through a third resistor and a capacitor.

[0008] Further, a first resistor is connected between the base and the emitter of the second triode.

[0009] Further, a diode is connected between the third resistor and the capacitor, and the positive pole of the diode is connected to the positive pole or the negative pole of the circuit.

[0010] Further, the third resistor and the capacitor form an RC time constant, and the RC time constant is 200 ns.

[0011] The beneficial effects of the present invention are as follows: Through the two-stage level inversion circuit to control the level inversion control, cooperate with the drive current amplification circuit to amplify the drive turn-on signal to drive the silicon carbide field effect transistor to conduct. At the same time, a fast turn-off circuit is also provided to control the fast turn-off of the first triode in the drive current amplification circuit to control the turn-off of the silicon carbide field effect transistor. And in the standby state of the silicon carbide field effect transistor, zero-power standby energy consumption can be achieved. Description of the Drawings

[0012] Figure 1 is the circuit diagram of the present invention. Detailed Embodiments

[0013] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present invention.

[0014] Those skilled in the art should understand that in the disclosure of the present invention, the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on the present invention.

[0015] It can be understood that the term "one" should be understood as "at least one" or "one or more". That is, in one embodiment, the number of an element can be one, while in other embodiments, the number of this element can be multiple. The term "one" should not be construed as a limitation on the quantity.

[0016] As Figure 1 described above, the present invention provides a zero-startup-power-consumption in-phase drive level conversion circuit, including a silicon carbide field-effect transistor Q5, a two-stage level inversion circuit for controlling level inversion and connected to the silicon carbide field-effect transistor Q5, a drive current amplification circuit for driving the silicon carbide field-effect transistor Q5 and connected to the two-stage level inversion circuit, and a fast turn-off circuit. The positive pole VCC of the circuit is connected to the drive current amplification circuit.

[0017] Among them, the two-stage level inversion circuit includes a first field-effect transistor Q3 and a second field-effect transistor Q4. The drain of the first field-effect transistor Q3 is connected to the gate of the second field-effect transistor Q4. The source of the first field-effect transistor Q3 and the source of the second field-effect transistor Q4 are commonly connected to the negative pole GND of the circuit. And the drain of the second field-effect transistor Q4 is connected to the gate of the silicon carbide field-effect transistor Q5. The source of the second field-effect transistor Q4 is connected to the source of the silicon carbide field-effect transistor Q5, so that when the first field-effect transistor Q3 is turned off and the second field-effect transistor Q4 is turned on, the silicon carbide field-effect transistor Q5 is in the cut-off state. When the first field-effect transistor Q3 is turned on and the second field-effect transistor Q4 is turned off, the silicon carbide field-effect transistor Q5 is in the on state.

[0018] The drive current amplification circuit includes a first triode Q1. The base of the first triode Q1 is connected to the drain of the first field-effect transistor Q3 through a fourth resistor R4. The collector of the first triode Q1 is connected to the gate of the silicon carbide field-effect transistor Q5 through a fifth resistor R5. And a second resistor R2 is arranged between the base and the emitter of the first triode Q1, so that when the first field-effect transistor Q3 is turned on and the second field-effect transistor Q4 is turned off, the second resistor R2 and the fourth resistor R4 apply voltage and turn on the first triode Q1.

[0019] The fast turn-off circuit includes a second triode Q2. The collector of the second triode Q2 is connected to the base of the first triode Q1. The emitter of the second triode Q2 is connected to the positive power supply VCC of the circuit. And the base of the second triode Q2 is connected to the gate of the first field-effect transistor Q3 and the offline controller 1 through a third resistor R3 and a capacitor C1.

[0020] Wherein, a first resistor R1 is connected between the base and the emitter of the second triode Q2; a diode D1 is connected between the third resistor R3 and the capacitor C1, and the positive electrode of the diode D1 is connected to the positive power supply VCC or the negative power supply GND of the circuit.

[0021] In a preferred embodiment of this solution, the third resistor R3 and the capacitor C1 form an RC time constant, and the RC time constant is 200 ns.

[0022] The usage mode of this solution is carried out according to the following three steps: I. Standby startup: During the standby startup time period, the offline controller 1 is at a low level, Q3 is turned off, Q4 is turned on, and the silicon carbide field-effect transistor drive is pulled low; at this time, all devices are in a cut-off state, and there are no power-consuming components, so the purpose of zero-power standby energy consumption can be achieved; II. Drive on: As the startup voltage VCC rises, since the offline controller will not start before reaching the startup voltage of 18V, the offline controller pin6 outputs a low voltage, and Q3 is in the off state. After the VCC voltage rises to 2V, Q4 starts to conduct, the silicon carbide field-effect transistor Q5 is turned off. After the VCC voltage reaches 18V, the offline driver starts to output a PWM waveform. When the output is at a high level, Q3 starts to conduct, Q4 is turned off, and at the same time, voltages are applied to R4 and R2, Q1 starts to conduct, and the silicon carbide field-effect transistor is driven through the resistor R5. The turn-on level is approximately equal to VCC, not limited by the PWM drive waveform. The amplitude of the PWM can be greater than when Q3 is fully turned on, usually 4.5V; III. Drive off: When the PWM is at a low level, Q3 is turned off, Q4 is turned on, and the silicon carbide field-effect transistor is turned off. At this time, Q2 is turned on under the RC time constant formed by C1 and R3 (usually the RC time constant is designed to be 200 ns). Q2 controls Q1 to turn off quickly, reducing the drive power consumption. When the next pwm waveform is turned on, C1 is quickly discharged through the diode D1, and usually the discharge is completed in 50 ns, preparing for the next turn-off to provide a suitable time for the turn-on of Q2.

[0023] The present invention is not limited to the above best embodiment. Anyone can obtain other various forms of products under the inspiration of the present invention. However, no matter what changes are made in its shape or structure, as long as it has a technical solution identical or similar to the present application, it falls within the protection scope of the present invention.

Claims

1. A same-phase drive level conversion circuit with zero startup power consumption, characterized in that: It includes a silicon carbide field-effect transistor Q5, a two-stage level inversion circuit for controlling level inversion and connected to the silicon carbide field-effect transistor Q5, and a drive current amplification circuit for driving the silicon carbide field-effect transistor Q5 and connected to the two-stage level inversion circuit. The positive pole VCC of the circuit is connected to the drive current amplification circuit; the two-stage level inversion circuit includes a first field-effect transistor Q3 and a second field-effect transistor Q4. The drain of the first field-effect transistor Q3 is connected to the gate of the second field-effect transistor Q4. The source of the first field-effect transistor Q3 and the source of the second field-effect transistor Q4 are commonly connected to the negative pole GND of the circuit. And the drain of the second field-effect transistor Q4 is connected to the gate of the silicon carbide field-effect transistor Q5. The source of the second field-effect transistor Q4 is connected to the source of the silicon carbide field-effect transistor Q5, so that when the first field-effect transistor Q3 is turned off and the second field-effect transistor Q4 is turned on, the silicon carbide field-effect transistor Q5 is in the cut-off state, and when the first field-effect transistor Q3 is turned on and the second field-effect transistor Q4 is turned off, the silicon carbide field-effect transistor Q5 is in the conducting state.

2. The in-phase drive level conversion circuit with zero startup power consumption according to claim 1, characterized in that: The drive current amplification circuit includes a first triode Q1. The base of the first triode Q1 is connected to the drain of the first field-effect transistor Q3 through a fourth resistor R4. The collector of the first triode Q1 is connected to the gate of the silicon carbide field-effect transistor Q5 through a fifth resistor R5. And a second resistor R2 is arranged between the base and the emitter of the first triode Q1, so that when the first field-effect transistor Q3 is turned on and the second field-effect transistor Q4 is turned off, the second resistor R2 and the fourth resistor R4 apply voltage and turn on the first triode Q1.

3. The in-phase drive level conversion circuit with zero startup power consumption according to claim 2, wherein: It further includes a fast turn-off circuit. The fast turn-off circuit includes a second triode Q2. The collector of the second triode Q2 is connected to the base of the first triode Q1. The emitter of the second triode Q2 is connected to the positive pole VCC of the circuit. And the base of the second triode Q2 is connected to the gate of the first field-effect transistor Q3 and the offline controller (1) through a third resistor R3 and a capacitor C1.

4. The in-phase drive level conversion circuit with zero startup power consumption according to claim 3, characterized in that: A first resistor R1 is connected between the base and the emitter of the second triode Q2.

5. The in-phase drive level conversion circuit with zero startup power consumption according to claim 3, characterized in that: A diode D1 is connected between the third resistor R3 and the capacitor C1, and the positive pole of the diode D1 is connected to the positive pole VCC or the negative pole GND of the circuit.

6. The in-phase drive level conversion circuit with zero startup power consumption according to claim 3, characterized in that: The third resistor R3 and the capacitor C1 form an RC time constant, and the RC time constant is 200 ns.

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