A 400 kHz power supply driving circuit

Abstract

The utility model relates to a kind of 400kHz power source drive circuit, including the input signal processing circuit, comparison control circuit and drive output circuit that are sequentially connected, the drive output circuit is according to chip selection signal output high level, low level or high resistance three kinds of states, to drive power transistor;Input signal processing circuit includes voltage follower U1A, inverter U1B, single-path pulse is divided into complementary double pulse with phase difference 180 °;Comparison control circuit obtains 0~500ns continuous adjustable dead zone by rotating potentiometer VR1 to output pulse;Drive output circuit includes drive chip U13, U14 and power decoupling, output resistance network, two chips are controlled output high level, low level or high resistance by chip selection, when abnormal, it is converted into high resistance protection;Circuit uses symmetrical modularization layout, it is suitable for 400kHz high-frequency power transistor drive, and the embodiment provides a kind of compact structure, dead zone controllable, protection perfect drive power supply, while reducing cost, efficiency and reliability are improved.

Description

Technical Field

[0001] This utility model relates to the field of high-frequency high-power power supply technology, and in particular to a 400kHz power source drive circuit. Background Technology

[0002] In high-end manufacturing fields such as semiconductors, solar photovoltaics, industrial coating, plasma cleaning, nanomaterials processes, and material surface modification, 400kHz sinusoidal high-power power supplies have become the core power source for critical process equipment. These power supplies typically need to be continuously adjustable within a wide power range of 5KW to 50KW, and must simultaneously meet stringent requirements such as frequency stability better than ±0.05%, total harmonic distortion less than 2%, peak-to-peak voltage ripple not exceeding 0.5%, voltage regulation within 50µs when the load increases by 10%–90%, and overall efficiency not less than 92%. More importantly, they must also pass SEMI S2 / S8, CE, and UL certifications, and possess multiple protection capabilities against overvoltage, overcurrent, overtemperature, and arcing. However, existing drive technologies generally struggle to balance dead-time accuracy, adjustability, three-state protection, and electromagnetic compatibility performance at such high switching frequencies.

[0003] For a long time, the industry has generally adopted half-bridge or full-bridge hard-switching topologies with gate transformers for driving. This approach results in a sharp increase in core losses at 400kHz, with turn-off spike voltages caused by leakage inductance reaching hundreds of volts. This necessitates the addition of an absorption network, leading to a 3%–5% decrease in efficiency. Furthermore, it results in poor gate signal consistency and easy magnetization of the bridge arms. Some manufacturers have switched to LLC, LCC, or series-parallel resonant topologies supplemented with general-purpose half-bridge driver chips such as IR2110 and UCC27714. Although soft switching reduces switching losses, these chips have a maximum operating frequency of only 500kHz, and their internal fixed dead time is set by on-chip resistors and cannot be adjusted online. When the ambient temperature or power device parameters drift, the dead time error can reach ±20%, which can easily cause SiC MOSFETs to shoot through. In addition, traditional chips can only output two levels, high and low, and lack high-impedance protection. Once arc discharge or load short circuit occurs during the process, the power transistor is very likely to be damaged twice.

[0004] With the commercialization of third-generation semiconductor devices (SiC, GaN), the demand for ultra-high-speed drives at 400kHz or even 2MHz is rapidly increasing. SiC MOSFETs can achieve dv / dt of 50V / ns at a switching frequency of 400kHz and an 800V bus, placing stringent requirements on the common-mode transient immunity (CMTI) of the driver chip at no less than 100KV / µs. At the same time, in order to reduce the reverse recovery loss of the body diode, the dead time needs to be precisely controlled within 50ns–200ns and dynamically fine-tuned as the device ages and temperature drifts. Existing analog solutions mostly use general-purpose PWM controllers such as NE555 and TL494, which have a frequency temperature drift of up to ±3% and a dead time determined by the RC network with a temperature drift of ±20%, which cannot meet the narrow dead time requirement at all. Although digital control solutions can generate complementary PWM with the help of FPGA or CPLD, the high-speed ADC, DAC and isolator links cause the system delay to exceed 100ns, and the dead time accuracy can only rely on software compensation. Moreover, digital signals are very easy to be falsely triggered in strong electromagnetic interference environments. On the other hand, process equipment also places higher demands on the size, reliability, and maintainability of drive circuits. Traditional discrete component layouts are scattered and the wiring is asymmetrical. The difference in drive delay between the upper and lower transistors due to parasitic inductance can reach more than 10ns, which can easily lead to bias magnetism in the magnetic core or resonant cavity, causing overheating failure. At the same time, the lack of integrated and modular design leads to excessive EM, and the whole machine needs additional shielding, which increases cost and size. Therefore, the existing technology has obvious shortcomings in high-frequency dead-time accuracy, online adjustability, three-state protection, and layout parasitic suppression. There is an urgent need for a new type of drive circuit that is compact, has adjustable dead time, has high impedance protection, and is suitable for high-frequency and high-power applications at 400kHz. Utility Model Content

[0005] In view of this, the present invention provides a 400kHz power source drive circuit, which effectively solves the technical pain points of high-frequency power supply switching loss and poor anti-interference. It is suitable for industrial equipment such as photovoltaic and plasma cleaning equipment, and provides a 400kHz power source drive circuit with compact structure, complementary phase, adjustable dead time and high impedance protection function.

[0006] To achieve the above objectives, this utility model provides a 400kHz power source driving circuit, including an input signal processing circuit, a comparison control circuit, and a drive output circuit; the input signal processing circuit is connected to the comparison control circuit, the comparison control circuit is connected to the drive output circuit, and the drive output circuit outputs three states—high level, low level, or high impedance—according to the chip select signal to drive the power transistor. The comparison control circuit includes a U5A comparator, a U6A comparator, a 49th resistor R49, a 53rd resistor R53, a 65th resistor R65, a 66th resistor R66, and a potentiometer VR1. The 1IN- terminal of the U5A comparator is connected to the 1IN- terminal of the U6A comparator. The 49th resistor R49 is connected to the connection point of the 1IN- terminal of the U5A comparator and the 1IN+ terminal of the U6A comparator. The 53rd resistor R53 and the potentiometer VR1 are connected in parallel and are connected to the connection point of the 1IN- terminal of the U5A comparator and the 1IN- terminal of the U6A comparator. The 1OUT terminal of the U5A comparator is connected to one end of the sixty-fifth resistor R65, and the 1OUT terminal of the U6A comparator is connected to one end of the sixty-sixth resistor R66.

[0007] Preferably, the input signal processing circuit includes a voltage follower U1A, an inverter U1B, a first resistor R1, a second resistor R2, a ninth resistor R9, a thirteenth resistor R13, a fourteenth resistor R14, a twenty-first resistor R21, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a thirty-third resistor R33, a thirty-fourth resistor R34, a forty-first resistor R41, a forty-second resistor R42, an eighty-first capacitor C81, and an eighty-second resistor R82. The second resistor R2 and the ninth resistor R9 are connected in series. The second resistor R2 and the ninth resistor R9 are connected in parallel with the first resistor R1. One end of the thirteenth resistor R13 and the fourteenth resistor R14 is connected to the connection point of the second resistor R2 and the ninth resistor R9. The other end of the thirteenth resistor R13 is connected to the 1IN+ terminal of the U1A voltage follower. The 1IN- terminal of the U1A voltage follower is connected to the twenty-fifth resistor R25. The other end of the twenty-fifth resistor R25 is connected to the 1OUT terminal of the U1A voltage follower. One end of the thirty-third resistor R33 is connected to the connection point of the twenty-fifth resistor R25 and the U1A voltage follower. The other end of the thirty-third resistor R33 is connected to the connection point of the forty-first resistor R41 and the eighty-first capacitor C81. The forty-first resistor R41 and the eighty-first capacitor C81 are connected in parallel. The other end of the fourteenth resistor R14 is connected to the 2IN- terminal of the U1B inverter. One end of the twenty-sixth resistor R26 is connected to the connection point of the fourteenth resistor R14 and the 2IN- terminal of the U1B inverter. The other end of the twenty-sixth resistor is connected to the 2OUT terminal of the U1B inverter. The twenty-first resistor R21 is connected to the 2IN+ terminal of the U1B inverter. The 2OUT terminal of the U1B inverter is connected to the thirty-fourth resistor R34. The other end of the thirty-fourth resistor R34 is connected to the connection point of the forty-second resistor R42 and the eighty-second capacitor C82. The forty-second resistor R42 and the eighty-second capacitor C82 are connected in parallel.

[0008] Preferably, the 1IN+ terminal of the U5A comparator is connected to the connection point of the 33rd resistor R33, the 41st resistor R41, and the 81st capacitor C81, and the 1IN+ terminal of the U6A comparator is connected to the connection point of the 42nd resistor R42, the 34th resistor R34, and the 82nd capacitor C82.

[0009] Preferably, the drive output circuit includes a U13 drive chip, a U14 drive chip, a 33rd capacitor C33, a 34th capacitor C34, a 49th capacitor C49, a 50th capacitor C50, a 73rd resistor R73, an 81st resistor R81, an 82nd resistor R82, an 89th resistor R89, a 90th resistor R90, a 113th resistor R113, a 114th resistor R114, a 121st resistor R121, and a 122nd resistor R122. The U13 driver chip's terminals 10, 11, 12, 13, 14, 15, 16, and 17 are connected to the connection point of the U5A comparator's 1OUT terminal and the sixty-fifth resistor R65. The U13 driver chip's OE1# terminal is connected to the seventy-third resistor R73. The U13 driver chip's VCC terminal is connected to the connection point of the thirty-third capacitor C33 and the forty-ninth capacitor C49. The thirty-third capacitor C33 and the forty-ninth capacitor C49 are connected in parallel. The U13 driver chip's terminals O0, O1, O2, and O3 are connected to the eighty-first resistor R... 81 are connected together. One end of the first 113 resistor R113 is connected to the connection point of the 81st resistor R81 and the O0, O1, O2 and O3 terminals of the U13 driver chip. The other end of the first 113 resistor R113 is connected to the 114th resistor R114. The other end of the first 114th resistor R114 is connected to the O4, O5, O6 and O7 terminals of the U13 driver chip. One end of the 82nd resistor R82 is connected to the connection point of the 114th resistor R114 and the O4, O5, O6 and O7 terminals of the U13 driver chip. The U14 driver chip's terminals 10, 11, 12, 13, 14, 15, 16, and 17 are connected to the connection point of the U6A comparator's 1OUT terminal and the sixty-sixth resistor R66. The U14 driver chip's VCC terminal is connected to the connection point of the thirty-fourth capacitor C34 and the fiftieth capacitor C50. The thirty-fourth capacitor C34 and the fiftieth capacitor C50 are connected in parallel. The U14 driver chip's terminals O0, O1, O2, and O3 are connected to the eighty-ninth resistor R89, and the one hundred and twenty-first resistor... One end of R121 is connected to the connection point of the 89th resistor R89 ​​and the O0, O1, O2 and O3 terminals of the U14 driver chip. The other end of the 121st resistor R121 is connected to the 122nd resistor R122. The other end of the 122nd resistor R122 is connected to the O4, O5, O6 and O7 terminals of the U14 driver chip. One end of the 90th resistor R90 is connected to the connection point of the 122nd resistor R122 and the O4, O5, O6 and O7 terminals of the U14 driver chip.

[0010] Preferably, the other end of the eighty-first resistor R81 is connected to the output terminal, the other end of the eighty-second resistor R82 is connected to the output terminal, the other end of the eighty-ninth resistor R89 ​​is connected to the output terminal, and the other end of the ninetieth resistor R90 is connected to the output terminal.

[0011] Compared with the prior art, the beneficial effects of this utility model are: This utility model, through the cooperation of voltage follower U1A and inverter U1B, directly splits a single pulse signal into two drive pulses with strictly complementary phases, eliminating the need for independent complementary PWM generators and complex logic circuits in traditional solutions, significantly reducing control complexity; the VR1 potentiometer connected in series with the +5V reference voltage can operate from 0–500... The stepless adjustment of the dead time within the nanosecond range not only meets the process requirements of narrow dead time for new power devices such as SiC and GaN, but also compensates for parameter changes caused by temperature drift and device aging, ensuring long-term system stability. The U13 and U14 driver chips support high, low, and high impedance tri-state output. When the load changes suddenly or an arc short circuit occurs, they immediately switch to the high impedance state, effectively suppressing bridge arm shoot-through and secondary breakdown, and significantly reducing the power tube failure rate. The overall symmetrical and modular layout, with equal-length traces and partitioned grounding design, reduces parasitic inductance and electromagnetic interference simultaneously, maintaining excellent EMC performance and reliability even at 400kHz high frequency. The 400kHz power source drive circuit provided by this invention offers a cost-effective solution for high-end process equipment in photovoltaic, semiconductor, and plasma cleaning industries. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of a 400kHz power source drive circuit according to the present invention. Detailed Implementation

[0014] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0015] This utility model provides the following technical solution: a 400kHz power source driving circuit, including an input signal processing circuit, a comparison control circuit, and a driving output circuit; the input signal processing circuit is connected to the comparison control circuit, the comparison control circuit is connected to the driving output circuit, and the driving output circuit outputs three states—high level, low level, or high impedance—according to the chip select signal to drive the power transistor; The input signal processing circuit includes a voltage follower U1A, an inverter U1B, a first resistor R1, a second resistor R2, a ninth resistor R9, a thirteenth resistor R13, a fourteenth resistor R14, a twenty-first resistor R21, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a thirty-third resistor R33, a thirty-fourth resistor R34, a forty-first resistor R41, a forty-second resistor R42, an eighty-first capacitor C81, and an eighty-second resistor R82. The second resistor R2 and the ninth resistor R9 are connected in series. The second resistor R2 and the ninth resistor R9 are connected in parallel with the first resistor R1. One end of the thirteenth resistor R13 and the fourteenth resistor R14 is connected to the connection point of the second resistor R2 and the ninth resistor R9. The other end of the thirteenth resistor R13 is connected to the 1IN+ terminal of the U1A voltage follower. The 1IN- terminal of the U1A voltage follower is connected to the twenty-fifth resistor R25. The other end of the twenty-fifth resistor R25 is connected to the 1OUT terminal of the U1A voltage follower. One end of the thirty-third resistor R33 is connected to the connection point of the twenty-fifth resistor R25 and the U1A voltage follower. The other end of the thirty-third resistor R33 is connected to the connection point of the forty-first resistor R41 and the eighty-first capacitor C81. The forty-first resistor R41 and the eighty-first capacitor C81 are connected in parallel. The other end of the fourteenth resistor R14 is connected to the 2IN- terminal of the U1B inverter. One end of the twenty-sixth resistor R26 is connected to the connection point of the fourteenth resistor R14 and the 2IN- terminal of the U1B inverter. The other end of the twenty-sixth resistor is connected to the 2OUT terminal of the U1B inverter. The twenty-first resistor R21 is connected to the 2IN+ terminal of the U1B inverter. The 2OUT terminal of the U1B inverter is connected to the thirty-fourth resistor R34. The other end of the thirty-fourth resistor R34 is connected to the connection point of the forty-second resistor R42 and the eighty-second capacitor C82. The forty-second resistor R42 and the eighty-second capacitor C82 are connected in parallel. The pulse signal passes through the resistor voltage and enters the U1A follower and U1B inverter respectively. The U1A follower and U1B inverter convert the signal into a pulse signal with a phase difference of 180 degrees.

[0016] The comparison control circuit includes comparator U5A, comparator U6A, resistor R49 (49th), resistor R53 (53rd), resistor R65 (65th), resistor R66 (66th), and potentiometer VR1. The 1IN- terminal of comparator U5A is connected to the 1IN- terminal of comparator U6A. Resistor R49 is connected to the connection point of the 1IN- terminal of comparator U5A and the 1IN+ terminal of comparator U6A. Resistor R53 and potentiometer VR1 are connected in parallel and connected to the connection point of the 1IN- terminal of comparator U5A and the 1IN- terminal of comparator U6A. Potentiometer VR1 is connected to the reference voltage +5V. The sliding terminal of VR1 outputs an adjustable reference voltage. The 1OUT terminal of comparator U5A is connected to one end of resistor R65 (the sixty-fifth resistor), and the 1OUT terminal of comparator U6A is connected to one end of resistor R66 (the sixty-sixth resistor). The 1IN+ terminal of the U5A comparator is connected to the connection point of the 33rd resistor R33, the 41st resistor R41, and the 81st capacitor C81. The 1IN+ terminal of the U6A comparator is connected to the connection point of the 42nd resistor R42, the 34th resistor R34, and the 82nd capacitor C82. The reference voltage +5V signal is divided to obtain VREF. After being compared with pulse signals A and B in comparators U5A and U6A, a narrow pulse with dead time is generated, which is then fed into driver chips U13 and U14 respectively. The dead time can be continuously adjusted by rotating VR1 to avoid power transistor shoot-through.

[0017] The drive output circuit includes driver chip U13, driver chip U14, capacitor C33 (33rd), capacitor C34 (34th), capacitor C49 (49th), capacitor C50 (50th), resistor R73 (73rd), resistor R81 (81st), resistor R82 (82nd), resistor R89 ​​(89th), resistor R90 (90th), resistor R113 (113th), resistor R114 (114th), resistor R121 (121st), and resistor R122 (122nd). The U13 driver chip's terminals L0, L1, L2, L3, L4, L5, L6, and L7 are connected to the connection point of the U5A comparator's 1OUT terminal and the 65th resistor R65. The U13 driver chip's OE1# terminal is connected to the 73rd resistor R73. The U13 driver chip's VCC terminal is connected to the connection point of the 33rd capacitor C33 and the 49th capacitor C49, which are connected in parallel. The U13 driver chip's terminals O0, O1, O2, and O3 are connected to the 81st resistor R8. 1. Connect one end of the 113th resistor R113 to the connection point of the 81st resistor R81 and the O0, O1, O2 and O3 terminals of the U13 driver chip; connect the other end of the 113th resistor R113 to the 114th resistor R114; connect the other end of the 114th resistor R114 to the O4, O5, O6 and O7 terminals of the U13 driver chip; connect one end of the 82nd resistor R82 to the connection point of the 114th resistor R114 and the O4, O5, O6 and O7 terminals of the U13 driver chip. The L0, L1, L2, L3, L4, L5, L6, and L7 terminals of the U14 driver chip are connected to the 1OUT terminal of the U6A comparator and the connection point of the sixty-sixth resistor R66. The VCC terminal of the U14 driver chip is connected to the connection point of the thirty-fourth capacitor C34 and the fiftieth capacitor C50. The thirty-fourth capacitor C34 and the fiftieth capacitor C50 are connected in parallel. The O0, O1, O2, and O3 terminals of the U14 driver chip are connected to the eighty-ninth resistor R89. One end of resistor eleven, R121, is connected to the connection point of resistor eighty-ninth, R89, and driver chip U14. The other end of resistor one hundred and twenty-first, R121, is connected to resistor one hundred and twenty-second, R122. The other end of resistor one hundred and twenty-second, R122, is connected to terminals O4, O5, O6, and O7 of driver chip U14. One end of resistor ninety, R90, is connected to the connection point of resistor one hundred and twenty-second, R122, and driver chip U14, O4, O5, O6, and O7. The other end of resistor R81 (eighty-first) is connected to the output terminal; the other end of resistor R82 (eighty-second) is connected to the output terminal; the other end of resistor R89 ​​(eighty-ninth) is connected to the output terminal; and the other end of resistor R90 (ninetieth) is connected to the output terminal. Driver chips U13 and U14 control the chip select signal and, based on the different chip select signals received, can output three different signal states: high level, low level, and high impedance, which are then output to the amplifying transistor to control the driving transistor.

[0018] The circuit inputs and outputs are shown in Table 1: Table 1

Claims

1. A 400kHz power source drive circuit, characterized in that, It includes an input signal processing circuit, a comparison control circuit, and a drive output circuit; the input signal processing circuit is connected to the comparison control circuit, the comparison control circuit is connected to the drive output circuit, and the drive output circuit outputs three states—high level, low level, or high impedance—according to the chip select signal to drive the power transistor. The comparison control circuit includes a U5A comparator, a U6A comparator, a 49th resistor R49, a 53rd resistor R53, a 65th resistor R65, a 66th resistor R66, and a potentiometer VR1. The 1IN- terminal of the U5A comparator is connected to the 1IN- terminal of the U6A comparator. The 49th resistor R49 is connected to the connection point of the 1IN- terminal of the U5A comparator and the 1IN+ terminal of the U6A comparator. The 53rd resistor R53 and the potentiometer VR1 are connected in parallel and are connected to the connection point of the 1IN- terminal of the U5A comparator and the 1IN- terminal of the U6A comparator. The 1OUT terminal of the U5A comparator is connected to one end of the sixty-fifth resistor R65, and the 1OUT terminal of the U6A comparator is connected to one end of the sixty-sixth resistor R66.

2. The 400kHz power source drive circuit according to claim 1, characterized in that, The input signal processing circuit includes a voltage follower U1A, an inverter U1B, a first resistor R1, a second resistor R2, a ninth resistor R9, a thirteenth resistor R13, a fourteenth resistor R14, a twenty-first resistor R21, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a thirty-third resistor R33, a thirty-fourth resistor R34, a forty-first resistor R41, a forty-second resistor R42, an eighty-first capacitor C81, and an eighty-second resistor R82. The second resistor R2 and the ninth resistor R9 are connected in series. The second resistor R2 and the ninth resistor R9 are connected in parallel with the first resistor R1. One end of the thirteenth resistor R13 and the fourteenth resistor R14 is connected to the connection point of the second resistor R2 and the ninth resistor R9. The other end of the thirteenth resistor R13 is connected to the 1IN+ terminal of the U1A voltage follower. The 1IN- terminal of the U1A voltage follower is connected to the twenty-fifth resistor R25. The other end of the twenty-fifth resistor R25 is connected to the 1OUT terminal of the U1A voltage follower. One end of the thirty-third resistor R33 is connected to the connection point of the twenty-fifth resistor R25 and the U1A voltage follower. The other end of the thirty-third resistor R33 is connected to the connection point of the forty-first resistor R41 and the eighty-first capacitor C81. The forty-first resistor R41 and the eighty-first capacitor C81 are connected in parallel. The other end of the fourteenth resistor R14 is connected to the 2IN- terminal of the U1B inverter. One end of the twenty-sixth resistor R26 is connected to the connection point of the fourteenth resistor R14 and the 2IN- terminal of the U1B inverter. The other end of the twenty-sixth resistor is connected to the 2OUT terminal of the U1B inverter. The twenty-first resistor R21 is connected to the 2IN+ terminal of the U1B inverter. The 2OUT terminal of the U1B inverter is connected to the thirty-fourth resistor R34. The other end of the thirty-fourth resistor R34 is connected to the connection point of the forty-second resistor R42 and the eighty-second capacitor C82. The forty-second resistor R42 and the eighty-second capacitor C82 are connected in parallel.

3. The 400kHz power source drive circuit according to claim 2, characterized in that, The 1IN+ terminal of the U5A comparator is connected to the connection point of the 33rd resistor R33, the 41st resistor R41, and the 81st capacitor C81. The 1IN+ terminal of the U6A comparator is connected to the connection point of the 42nd resistor R42, the 34th resistor R34, and the 82nd capacitor C82.

4. The 400kHz power source drive circuit according to claim 1, characterized in that, The drive output circuit includes a U13 drive chip, a U14 drive chip, a 33rd capacitor C33, a 34th capacitor C34, a 49th capacitor C49, a 50th capacitor C50, a 73rd resistor R73, an 81st resistor R81, an 82nd resistor R82, an 89th resistor R89, a 90th resistor R90, a 113th resistor R113, a 114th resistor R114, a 121st resistor R121, and a 122nd resistor R122. The U13 driver chip's terminals 10, 11, 12, 13, 14, 15, 16, and 17 are connected to the connection point of the U5A comparator's 1OUT terminal and the sixty-fifth resistor R65. The U13 driver chip's OE1# terminal is connected to the seventy-third resistor R73. The U13 driver chip's VCC terminal is connected to the connection point of the thirty-third capacitor C33 and the forty-ninth capacitor C49. The thirty-third capacitor C33 and the forty-ninth capacitor C49 are connected in parallel. The U13 driver chip's terminals O0, O1, O2, and O3 are connected to the eighty-first resistor R... 81 are connected together. One end of the first 113 resistor R113 is connected to the connection point of the 81st resistor R81 and the O0, O1, O2 and O3 terminals of the U13 driver chip. The other end of the first 113 resistor R113 is connected to the 114th resistor R114. The other end of the first 114th resistor R114 is connected to the O4, O5, O6 and O7 terminals of the U13 driver chip. One end of the 82nd resistor R82 is connected to the connection point of the 114th resistor R114 and the O4, O5, O6 and O7 terminals of the U13 driver chip. The U14 driver chip's terminals 10, 11, 12, 13, 14, 15, 16, and 17 are connected to the connection point of the U6A comparator's 1OUT terminal and the sixty-sixth resistor R66. The U14 driver chip's VCC terminal is connected to the connection point of the thirty-fourth capacitor C34 and the fiftieth capacitor C50. The thirty-fourth capacitor C34 and the fiftieth capacitor C50 are connected in parallel. The U14 driver chip's terminals O0, O1, O2, and O3 are connected to the eighty-ninth resistor R89, and the one hundred and twenty-first resistor... One end of R121 is connected to the connection point of the 89th resistor R89 ​​and the O0, O1, O2 and O3 terminals of the U14 driver chip. The other end of the 121st resistor R121 is connected to the 122nd resistor R122. The other end of the 122nd resistor R122 is connected to the O4, O5, O6 and O7 terminals of the U14 driver chip. One end of the 90th resistor R90 is connected to the connection point of the 122nd resistor R122 and the O4, O5, O6 and O7 terminals of the U14 driver chip.

5. The 400kHz power source drive circuit according to claim 4, characterized in that, The other end of the eighty-first resistor R81 is connected to the output terminal, the other end of the eighty-second resistor R82 is connected to the output terminal, the other end of the eighty-ninth resistor R89 ​​is connected to the output terminal, and the other end of the ninetieth resistor R90 is connected to the output terminal.

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