Power supply of gallium nitride power chip

Abstract

The invention relates to the technical field of power supply circuits, and discloses a gallium nitride power chip power supply which comprises an AC input, an EMI filter circuit, a gallium nitride power switch, a switch transformer, a rectification filter circuit, a DC output, a voltage detection feedback circuit, a PWM control circuit, a current limiting circuit and a temperature protection circuit. The AC input, the EMI filter circuit, the gallium nitride power switch, the switch transformer, the rectification filter circuit and the DC output are connected in sequence; the rectification filter circuit is also connected with the voltage detection feedback circuit, and the voltage detection feedback circuit is connected with the PWM control circuit. The output end of the gallium nitride power switch is further connected with the circuit limiting circuit, and the current limiting circuit is connected with the PWM control circuit through the temperature protection circuit. The power supply of the gallium nitride power chip provided by the invention has the advantages of more stable output, larger adjustment range, stronger anti-interference capability and better overload and temperature protection performance.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply circuits, and in particular to a power supply for a gallium nitride power chip. Background Art

[0002] Gallium nitride power chip (GaN) is a new type of semiconductor material with excellent power and high-frequency characteristics. It is widely used in high-efficiency, high-frequency and high-temperature power electronic applications. For power applications, gallium nitride power chips can significantly reduce the size and weight of the system while providing high efficiency and high density.

[0003] However, the power supply of traditional GaN power chips has the following problems: 1. The EMI noise is large, which causes great interference to the surrounding circuits; 2. The output voltage is unstable and the adjustment range is small; 3. The output current cannot be monitored and limited in real time, which easily leads to overload protection; 4. The temperature detection is inaccurate and the chip cannot be protected from high temperature damage in time.

[0004] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0005] In view of the problems in the related art, the present invention proposes a power supply of a gallium nitride power chip to overcome the above technical problems existing in the existing related art.

[0006] To this end, the specific technical solution adopted by the present invention is as follows:

[0007] A power supply for a gallium nitride power chip, comprising an AC input, an EMI filter circuit, a gallium nitride power switch, a switching transformer, a rectifier filter circuit, a DC output, a voltage detection feedback circuit, a PWM control circuit, a current limiting circuit and a temperature protection circuit; wherein the AC input, the EMI filter circuit, the gallium nitride power switch, the switching transformer, the rectifier filter circuit and the DC output are connected in sequence; the rectifier filter circuit is also connected to the voltage detection feedback circuit, and the voltage detection feedback circuit is connected to the PWM control circuit; the output end of the gallium nitride power switch is also connected to the current limiting circuit, and the current limiting circuit is connected to the PWM control circuit through the temperature protection circuit.

[0008] Furthermore, the EMI filtering circuit includes capacitor C1, capacitor C2, capacitor C3, inductor L1 and inductor L2, and common-mode inductor L3; wherein, one end of the inductor L1 is respectively connected to one end of the capacitor C1 and the input end of the common-mode inductor L3, and the other end of the capacitor C1 is respectively connected to one end of the inductor L2 and the other input end of the common-mode inductor L3; the output end of the common-mode inductor L3 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to one end of the capacitor C3 and is grounded, and the other end of the capacitor C3 is connected to the other output end of the common-mode inductor L3.

[0009] Furthermore, the voltage detection feedback circuit includes a feedback sub-circuit and a voltage detection sampling sub-circuit, the output end of the feedback sub-circuit is connected to the input end of the PWM control circuit, the input end of the feedback sub-circuit is connected to the output end of the voltage detection sampling sub-circuit, and the input end of the voltage detection sampling sub-circuit is connected to the output end of the rectifier and filter circuit.

[0010] Furthermore, the PWM control circuit includes an operational amplifier U1, a capacitor C4, a resistor R1, a resistor R2, a resistor R3, an adjustable resistor R4, a diode D1 and a diode D2; wherein the first pin of the operational amplifier U1 is respectively connected to one end of the resistor R2 and one end of the resistor R3, the second pin of the operational amplifier U1 is respectively connected to the other end of the resistor R2 and one end of the resistor R1, and the other end of the resistor R1 is grounded; the third pin of the operational amplifier U1 is respectively connected to the cathode of the diode D1, the anode of the diode D2 and one end of the capacitor C4, the other end of the capacitor C4 is grounded, the anode of the diode D1 is connected to one end of the adjustable resistor R4, the other end of the adjustable resistor R4 is connected to the cathode of the diode D2, and the sliding end of the adjustable resistor R4 is connected to the other end of the resistor R3.

[0011] Furthermore, the model of the operational amplifier U1 is LF353D.

[0012] Further, the current limiting circuit includes a MOS tube Q1, a MOS tube Q2, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a capacitor C5, a capacitor C6 and a diode D3; wherein the gate of the MOS tube Q1 is respectively connected to one end of the capacitor C5 and one end of the resistor R6, the source of the MOS tube Q1 is respectively connected to the other end of the capacitor C5, one end of the capacitor C6, the source of the MOS tube Q2 and one end of the resistor R7, the drain of the MOS tube Q1 is respectively connected to one end of the resistor R5, the other end of the capacitor C6 and the gate of the MOS tube Q2, and the other end of the resistor R5 is grounded; the drain of the MOS tube Q2 is respectively connected to the other end of the resistor R6, one end of the resistor R8, the other end of the resistor R7 and the positive electrode of the diode D3, and the other end of the resistor R8 is grounded.

[0013] Furthermore, the MOS transistor Q1 and the MOS transistor Q2 are both N-channel MOS transistors.

[0014] Furthermore, the temperature protection circuit includes a thermistor Rntc1, a thermistor Rntc2, a resistor R9, a resistor R10, a diode D4, a diode D5 and a transistor Q3; wherein one end of the resistor R9 is connected to one end of the thermistor Rntc2, the other end of the resistor R9 is respectively connected to one end of the thermistor Rntc1 and the positive electrode of the diode D4, the other end of the thermistor Rntc1 is respectively connected to one end of the resistor R10 and the emitter of the transistor Q3 and is grounded; the base of the transistor Q3 is respectively connected to the negative electrode of the diode D5 and the negative electrode of the diode D4, and the positive electrode of the diode D5 is respectively connected to the other end of the resistor R10 and the other end of the thermistor Rntc2.

[0015] Furthermore, the transistor Q3 is an NPN transistor.

[0016] Furthermore, the rectification and filtering circuit includes a rectifier bridge DB and a capacitor C7, and the capacitor is connected in parallel with the rectifier bridge DB.

[0017] The beneficial effects of the present invention are as follows: electromagnetic interference is effectively suppressed by the EMI filter circuit, and interference to surrounding circuits is reduced; the voltage detection feedback circuit realizes real-time detection and adjustment of the output voltage, and the output voltage is more stable and has a larger adjustable range; the current limiting circuit realizes real-time monitoring and limitation of the output current, effectively preventing overload; the temperature protection circuit accurately detects the chip temperature and quickly cuts off the power supply to protect the chip when the temperature is too high. The power supply of the gallium nitride power chip provided by the present invention has more stable output, a larger adjustment range, stronger anti-interference ability, and better overload and temperature protection performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 is a circuit principle block diagram of a power supply of a gallium nitride power chip according to an embodiment of the present invention;

[0020] Figure 2 is a circuit diagram of an EMI filter circuit in a power supply of a gallium nitride power chip according to an embodiment of the present invention;

[0021] Figure 3 is a circuit diagram of a PWM control circuit in a power supply of a gallium nitride power chip according to an embodiment of the present invention;

[0022] Figure 4 is a circuit diagram of a current limiting circuit in a power supply of a gallium nitride power chip according to an embodiment of the present invention;

[0023] Figure 5 is a circuit diagram of a temperature protection circuit in a power supply of a gallium nitride power chip according to an embodiment of the present invention;

[0024] Figure 6 The present invention is a circuit diagram of a rectifier and filter circuit in a power supply of a gallium nitride power chip according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention and are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in the field should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0026] According to an embodiment of the present invention, a power supply for a gallium nitride power chip is provided.

[0027] The present invention is further described with reference to the accompanying drawings and specific embodiments. Figure 1-Figure 6 As shown, the power supply of the gallium nitride power chip according to the embodiment of the present invention includes an AC input, an EMI filter circuit, a gallium nitride power switch, a switching transformer, a rectifier filter circuit, a DC output, a voltage detection feedback circuit, a PWM control circuit, a current limiting circuit and a temperature protection circuit;

[0028] The AC input, the EMI filter circuit, the gallium nitride power switch, the switching transformer, the rectifier filter circuit and the DC output are connected in sequence; the rectifier filter circuit is also connected to the voltage detection feedback circuit, and the voltage detection feedback circuit is connected to the PWM control circuit; the output end of the gallium nitride power switch is also connected to the current limiting circuit, and the current limiting circuit is connected to the PWM control circuit through the temperature protection circuit.

[0029] The EMI filter circuit includes capacitor C1, capacitor C2, capacitor C3, inductor L1 and inductor L2, and common mode inductor L3;

[0030] Among them, one end of the inductor L1 is respectively connected to one end of the capacitor C1 and the input end of the common-mode inductor L3, and the other end of the capacitor C1 is respectively connected to one end of the inductor L2 and the other input end of the common-mode inductor L3; the output end of the common-mode inductor L3 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to one end of the capacitor C3 and grounded, and the other end of the capacitor C3 is connected to the other output end of the common-mode inductor L3.

[0031] Specifically, the principle of the EMI filter circuit is as follows: one end of the capacitor C1 is connected to one end of the inductor L1, and is also connected to the input end of the common mode inductor L3. The other end of the capacitor C1 is connected to one end of the inductor L2, and is also connected to the other input end of the common mode inductor L3. Such a connection forms a low-pass filter for filtering out high-frequency common mode noise; the common mode inductor L3 is connected to the capacitor C3 through the capacitor C2, and the output end of the common mode inductor L3 is connected to one end of the capacitor C2. The other output end of the common mode inductor L3 is connected to the other end of the capacitor C3 and is grounded. The common mode inductor L3 plays a role in suppressing common mode noise in the circuit. The capacitor C2 and the capacitor C3 are connected together through the common mode inductor L3, and the other end of the capacitor C3 is grounded. Such a connection forms a high-frequency filter for filtering out low-frequency common mode noise.

[0032] The voltage detection feedback circuit includes a feedback subcircuit and a voltage detection sampling subcircuit, the output end of the feedback subcircuit is connected to the input end of the PWM control circuit, the input end of the feedback subcircuit is connected to the output end of the voltage detection sampling subcircuit, and the input end of the voltage detection sampling subcircuit is connected to the output end of the rectifier and filter circuit.

[0033] Specifically, a feedback circuit is a circuit that compares the output signal with the input signal and feeds the comparison result back to the system as a control signal. Its function is to adjust the input of the system according to the difference in the output signal so that the output signal is as close to the desired reference signal as possible. It usually consists of the following components:

[0034] Comparator: used to compare the difference between the output signal and the reference signal;

[0035] Error amplifier: amplifies the comparator output signal and processes it with other signals;

[0036] Controller: According to the output signal of the error amplifier, adjust the input of the system to achieve a stable control effect;

[0037] The voltage detection sampling circuit is used to monitor and measure the voltage value in the circuit to achieve voltage protection and control. It usually consists of the following components:

[0038] Voltage sensor: used to detect the voltage in the circuit and convert it into a corresponding electrical signal;

[0039] Sampling circuit: samples and processes the electrical signal output by the voltage sensor to obtain an accurate voltage value;

[0040] Comparator: compares the voltage value output by the sampling circuit with the preset threshold value to determine whether the voltage exceeds the set range;

[0041] Controller: Performs corresponding protection or control operations based on the output signal of the comparator, such as triggering an alarm, cutting off the circuit, or adjusting the power output.

[0042] The PWM control circuit includes an operational amplifier U1, a capacitor C4, a resistor R1, a resistor R2, a resistor R3, an adjustable resistor R4, a diode D1 and a diode D2;

[0043] Among them, the first pin of the operational amplifier U1 is respectively connected to one end of the resistor R2 and one end of the resistor R3, the second pin of the operational amplifier U1 is respectively connected to the other end of the resistor R2 and one end of the resistor R1, and the other end of the resistor R1 is grounded; the third pin of the operational amplifier U1 is respectively connected to the cathode of the diode D1, the anode of the diode D2 and one end of the capacitor C4, the other end of the capacitor C4 is grounded, the anode of the diode D1 is connected to one end of the adjustable resistor R4, the other end of the adjustable resistor R4 is connected to the cathode of the diode D2, and the sliding end of the adjustable resistor R4 is connected to the other end of the resistor R3.

[0044] Specifically, the principle of the PWM control circuit is as follows: the operational amplifier U1 compares the input signal with the feedback signal through negative feedback and outputs a control signal; the resistors R1, R2 and R3, and the adjustable resistor R4 constitute a voltage divider circuit to divide the input signal; by adjusting the sliding end of the adjustable resistor R4, the voltage divider ratio can be changed, thereby adjusting the feedback signal of the operational amplifier U1; the diodes D1 and D2 play a role in limiting the feedback signal to ensure the correct polarity of the output signal.

[0045] By adjusting the sliding end of the adjustable resistor R4, the voltage divider ratio can be changed, thereby changing the feedback signal of the operational amplifier U1. According to the change of the feedback signal, the PWM control circuit can generate a pulse width analog signal with different duty cycles. This signal can be used to control various circuits, such as driving motors, adjusting power supply output, etc.

[0046] The current limiting circuit includes a MOS transistor Q1, a MOS transistor Q2, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a capacitor C5, a capacitor C6 and a diode D3;

[0047] The gate of the MOS tube Q1 is respectively connected to one end of the capacitor C5 and one end of the resistor R6, the source of the MOS tube Q1 is respectively connected to the other end of the capacitor C5, one end of the capacitor C6, the source of the MOS tube Q2 and one end of the resistor R7, the drain of the MOS tube Q1 is respectively connected to one end of the resistor R5, the other end of the capacitor C6 and the gate of the MOS tube Q2, and the other end of the resistor R5 is grounded; the drain of the MOS tube Q2 is respectively connected to the other end of the resistor R6, one end of the resistor R8, the other end of the resistor R7 and the positive electrode of the diode D3, and the other end of the resistor R8 is grounded.

[0048] Specifically, the principle of the current limiting circuit is as follows: when the input current exceeds the limiting threshold, the MOS tube Q1 will start to conduct, and after conducting, a feedback voltage will be generated through R5, and the conduction of the MOS tube Q2 will be controlled through the gate of the MOS tube Q2; after the MOS tube Q2 is conducted, the current flows through the diode D3 through the resistor R8, so that the current flows through the limiting circuit; when the input current is lower than the limiting threshold, the MOS tube Q1 is not conducted, the MOS tube Q2 is also not conducted, and the current is not limited.

[0049] By adjusting the values ​​of resistors R5, R6, R7 and R8, the current limiting threshold can be set. When the input current exceeds the set threshold, the circuit will limit the flow of current to protect the circuit or device.

[0050] The temperature protection circuit includes a thermistor Rntc1, a thermistor Rntc2, a resistor R9, a resistor R10, a diode D4, a diode D5 and a transistor Q3;

[0051] Among them, one end of the resistor R9 is connected to one end of the thermistor Rntc2, the other end of the resistor R9 is respectively connected to one end of the thermistor Rntc1 and the positive electrode of the diode D4, the other end of the thermistor Rntc1 is respectively connected to one end of the resistor R10 and the emitter of the transistor Q3 and is grounded; the base of the transistor Q3 is respectively connected to the negative electrode of the diode D5 and the negative electrode of the diode D4, and the positive electrode of the diode D5 is respectively connected to the other end of the resistor R10 and the other end of the thermistor Rntc2.

[0052] Specifically, the principle of the temperature protection circuit is as follows: when the temperature rises, the resistance values ​​of thermistors Rntc1 and Rntc2 will change, which will cause the voltage in the voltage divider circuit to change; when the voltage exceeds the set threshold, transistor Q3 will start to conduct, at which time, a conduction path is formed between the collector and emitter of Q3 to trigger subsequent protection measures; the protection measures may be turning off the power supply, triggering an alarm or other related operations to prevent the temperature from continuing to rise and causing damage.

[0053] The rectification and filtering circuit includes a rectifier bridge DB and a capacitor C7, and the capacitor is connected in parallel with the rectifier bridge DB.

[0054] Specifically, the rectifier bridge DB is composed of four diodes, usually four diodes connected in quadrature. It is used to convert the AC input signal into a unidirectional DC signal. When the input signal is in the positive half cycle, the current flows from the AC input to the load through the conduction path of two diodes. When the input signal is in the negative half cycle, the current still flows from the AC input to the load through the conduction path of the other two diodes. In this way, the rectifier bridge can convert the AC input signal into a unidirectional DC output;

[0055] Capacitor C7 is connected in parallel with the rectifier bridge DB to filter out the ripple in the rectified DC signal. When the DC signal output by the rectifier bridge has ripples, capacitor C7 will act as an energy storage device to absorb the energy of the ripple part. In this way, the ripple in the output voltage can be reduced through the charging and discharging process of the capacitor.

[0056] Specifically, the operational amplifier U1 is of model LF353D. Both the MOS transistor Q1 and the MOS transistor Q2 are N-channel MOS transistors. The transistor Q3 is an NPN transistor.

[0057] In summary, with the help of the above technical solutions of the present invention, electromagnetic interference is effectively suppressed through the EMI filter circuit, reducing interference to surrounding circuits; the voltage detection feedback circuit realizes real-time detection and adjustment of the output voltage, and the output voltage is more stable and has a larger adjustable range; the current limiting circuit realizes real-time monitoring and limitation of the output current, effectively preventing overload; the temperature protection circuit accurately detects the chip temperature and quickly cuts off the power supply to protect the chip when the temperature is too high. The power supply of the gallium nitride power chip provided by the present invention has more stable output, a larger adjustment range, stronger anti-interference ability, and better overload and temperature protection performance.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A power supply for a gallium nitride power chip, characterized in that: Including AC input, EMI filter circuit, GaN power switch, switching transformer, rectifier filter circuit, DC output, voltage detection feedback circuit, PWM control circuit, current limiting circuit and temperature protection circuit; The AC input, the EMI filter circuit, the GaN power switch, the switch transformer, the rectifier filter circuit and the DC output are connected in sequence; The rectifier filter circuit is also connected to the voltage detection feedback circuit, and the voltage detection feedback circuit is connected to the PWM control circuit; The output end of the gallium nitride power switch is also connected to the current limiting circuit, and the current limiting circuit is connected to the PWM control circuit through the temperature protection circuit.

2. A gallium nitride power chip power supply according to claim 1, characterized in that: The EMI filter circuit includes capacitor C1, capacitor C2, capacitor C3, inductor L1 and inductor L2, and common mode inductor L3; One end of the inductor L1 is connected to one end of the capacitor C1 and the input end of the common-mode inductor L3, and the other end of the capacitor C1 is connected to one end of the inductor L2 and the other input end of the common-mode inductor L3. The output end of the common-mode inductor L3 is connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to one end of the capacitor C3 and is grounded, and the other end of the capacitor C3 is connected to the other output end of the common-mode inductor L3.

3. The power supply of a gallium nitride power chip according to claim 1, characterized in that: The voltage detection feedback circuit includes a feedback subcircuit and a voltage detection sampling subcircuit, the output end of the feedback subcircuit is connected to the input end of the PWM control circuit, the input end of the feedback subcircuit is connected to the output end of the voltage detection sampling subcircuit, and the input end of the voltage detection sampling subcircuit is connected to the output end of the rectifier and filter circuit.

4. The power supply of a gallium nitride power chip according to claim 1, characterized in that: The PWM control circuit includes an operational amplifier U1, a capacitor C4, a resistor R1, a resistor R2, a resistor R3, an adjustable resistor R4, a diode D1 and a diode D2; The first pin of the operational amplifier U1 is connected to one end of the resistor R2 and one end of the resistor R3 respectively, the second pin of the operational amplifier U1 is connected to the other end of the resistor R2 and one end of the resistor R1 respectively, and the other end of the resistor R1 is grounded; The third pin of the operational amplifier U1 is respectively connected to the cathode of the diode D1, the anode of the diode D2 and one end of the capacitor C4, the other end of the capacitor C4 is grounded, the anode of the diode D1 is connected to one end of the adjustable resistor R4, the other end of the adjustable resistor R4 is connected to the cathode of the diode D2, and the sliding end of the adjustable resistor R4 is connected to the other end of the resistor R3.

5. The power supply of a gallium nitride power chip according to claim 4, characterized in that: The model of the operational amplifier U1 is LF353D.

6. The power supply of a gallium nitride power chip according to claim 1, characterized in that: The current limiting circuit includes a MOS transistor Q1, a MOS transistor Q2, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a capacitor C5, a capacitor C6 and a diode D3; The gate of the MOS transistor Q1 is respectively connected to one end of the capacitor C5 and one end of the resistor R6, the source of the MOS transistor Q1 is respectively connected to the other end of the capacitor C5, one end of the capacitor C6, the source of the MOS transistor Q2 and one end of the resistor R7, the drain of the MOS transistor Q1 is respectively connected to one end of the resistor R5, the other end of the capacitor C6 and the gate of the MOS transistor Q2, and the other end of the resistor R5 is grounded; The drain of the MOS transistor Q2 is respectively connected to the other end of the resistor R6, one end of the resistor R8, the other end of the resistor R7 and the anode of the diode D3, and the other end of the resistor R8 is grounded.

7. The power supply of a gallium nitride power chip according to claim 6, characterized in that: The MOS transistor Q1 and the MOS transistor Q2 are both N-channel MOS transistors.

8. The power supply of a gallium nitride power chip according to claim 1, characterized in that: The temperature protection circuit includes a thermistor Rntc1, a thermistor Rntc2, a resistor R9, a resistor R10, a diode D4, a diode D5 and a transistor Q3; One end of the resistor R9 is connected to one end of the thermistor Rntc2, the other end of the resistor R9 is respectively connected to one end of the thermistor Rntc1 and the positive electrode of the diode D4, and the other end of the thermistor Rntc1 is respectively connected to one end of the resistor R10 and the emitter of the transistor Q3 and is grounded; The base of the transistor Q3 is connected to the cathode of the diode D5 and the cathode of the diode D4 respectively, and the anode of the diode D5 is connected to the other end of the resistor R10 and the other end of the thermistor Rntc2 respectively.

9. The power supply of a gallium nitride power chip according to claim 8, characterized in that: The transistor Q3 is an NPN transistor.

10. The power supply of a gallium nitride power chip according to claim 1, characterized in that: The rectification and filtering circuit includes a rectifier bridge DB and a capacitor C7, and the capacitor is connected in parallel with the rectifier bridge DB.

Images