Self-powered dual complementary magnetic isolation driving circuit and working method thereof

Abstract

The application relates to a self-powered double-path complementary magnetic isolation driving circuit and a working method thereof. The circuit comprises a first totem pole circuit, a second totem pole circuit, a magnetic isolation transmission circuit, a first signal adjusting circuit, a second signal adjusting circuit and a power supply circuit. The input end of the first totem pole circuit is connected with a first PWM signal, and the output end is connected with the first input end of the magnetic isolation transmission circuit. The input end of the second totem pole circuit is connected with a second PWM signal, and the output end is connected with the second input end of the magnetic isolation transmission circuit. The first output end of the magnetic isolation transmission circuit is connected with the input end of the first signal adjusting circuit, and the second output end is connected with the input end of the second signal adjusting circuit. The power supply circuit is used for providing a power supply voltage. Different switch driving controls can be realized by selecting different bridge drivers, and a self-powered circuit structure is adopted, so that a separate power supply is not needed to provide the power supply voltage for the bridge driver.

Description

Technical Field

[0001] This invention relates to the field of isolated DC / DC power supply circuit technology, specifically to a self-powered dual-path complementary magnetic isolation drive circuit and its operating method. Background Technology

[0002] Phase-shifted full-bridge and LLC resonant topologies, due to the soft-switching operation of the switching transistors, exhibit high conversion efficiency and excellent EMI characteristics, making them preferred topologies for high-power isolated power supplies. In isolated DC / DC power supplies, isolation drive circuits are widely used to achieve primary-secondary isolation. Currently, the commonly used isolation drive solutions mainly include dedicated isolation drive chips and magnetic isolation drives.

[0003] Figure 1 A typical application circuit for the TI UCC21520 is presented. The UCC21520 is a dedicated capacitor-isolated dual-channel gate driver. Isolation driving functionality can be achieved by configuring appropriate peripheral circuitry. The circuit structure is relatively simple. Figure 1 As can be seen, the primary and secondary sides require power supplies VCC and VDD respectively to provide two isolated power supply voltages. Due to the limitations of the chip itself, it is only suitable for driving MOSFETs, IGBTs, and SiC MOSFETs, and not for GaN drivers. Currently, there are no dedicated GaN isolated driver chips available domestically or internationally.

[0004] Figure 2 The invention described is a magnetically isolated drive circuit disclosed in Chinese patent CN109742952B. This magnetically isolated drive circuit adopts a transformer winding direct drive method, and the circuit structure is relatively simple. However, the drive level cannot be precisely controlled, and it is only suitable for MOSFET and IGBT drives, not GaN drives.

[0005] Figure 3 Another existing magnetically isolated drive circuit is presented. The magnetic isolation transformer only provides signal isolation and transmission. The complementary PWM signal obtained after transformer isolation is sent to the bridge driver N1, which performs the driving function. This circuit has strong functional expandability; by selecting bridge drivers with different functions, it can drive MOSFET, IGBT, and GaN devices. Figure 3 N1 in the diagram is an IR2110 driver, capable of driving MOSFETs and IGBTs. For driving GaN devices, a dedicated GaN bridge driver, such as the NCP51820, should be selected for N1. Figure 3 It is evident that the primary circuit requires a separate power supply VDD to provide power to chip N1.

[0006] In the above circuit, Figure 1As a dedicated isolated driver chip, it is limited by the chip's own functions and cannot implement GaN driving, resulting in poor functional expandability; Figure 2 The transformer winding direct drive method cannot achieve precise control of the drive level, and it is also not suitable for GaN drive, resulting in poor functional expandability. Figure 3 Using magnetic isolation + bridge driver, different switching transistors can be driven and controlled by selecting different bridge drivers, which has strong functional expandability. However, the primary side requires a separate power supply to provide power voltage to the bridge driver. Summary of the Invention

[0007] The purpose of this invention is to provide a self-powered dual-path complementary magnetic isolation drive circuit and its working method. This circuit can overcome the shortcomings of the prior art. Different switching transistor drive controls can be achieved by selecting different bridge drivers. At the same time, it adopts a self-powered circuit structure, eliminating the need for a single-ended power supply to provide power voltage to the bridge driver.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect of the invention, a self-powered dual-path complementary magnetic isolation drive circuit is provided.

[0009] Specifically, the circuit includes: a first totem pole circuit, a second totem pole circuit, a magnetically isolated transmission circuit, a first signal adjustment circuit, a second signal adjustment circuit, and a power supply circuit.

[0010] The input terminal of the first totem pole circuit is connected to the first PWM signal, and the output terminal is connected to the first input terminal of the magnetically isolated transmission circuit.

[0011] The input terminal of the second totem pole circuit is connected to the second PWM signal, and the output terminal is connected to the second input terminal of the magnetically isolated transmission circuit.

[0012] The first output terminal of the magnetically isolated transmission circuit is connected to the input terminal of the first signal adjustment circuit, and the second output terminal is connected to the input terminal of the second signal adjustment circuit.

[0013] The power supply circuit is used to provide the power supply voltage.

[0014] Furthermore, the circuit also includes a first input terminal Vi1, a second input terminal Vi2, a first output terminal Vo1, a second output terminal Vo2, and a third output terminal Vo3.

[0015] The first PWM signal is input to the first totem pole circuit via the first input terminal Vi1, and the second PWM signal is input to the second totem pole circuit via the second input terminal Vi2.

[0016] The first PWM signal and the second PWM signal are two complementary PWM signals output by the PWM controller. The two complementary PWM signals are sent to the magnetically isolated transmission circuit after being enhanced by the first totem pole circuit and the second totem pole circuit, respectively.

[0017] The magnetically isolated transmission circuit is used for the isolated transmission of two complementary PWM signals. The output terminal of the first signal adjustment circuit is connected to the first output terminal Vo1, and the output terminal of the second signal adjustment circuit is connected to the second output terminal Vo2; the first output terminal Vo1 and the second output terminal Vo2 are respectively connected to the two input terminals of the bridge driver chip.

[0018] The first signal adjustment circuit and the second signal adjustment circuit are used to ensure that the output PWM signal follows the two complementary input PWM signals in real time.

[0019] The output terminal of the power supply circuit is connected to the third output terminal Vo3. This circuit is used to implement the voltage doubler rectification function to provide DC voltage to the bridge driver chip to achieve isolated self-powered operation.

[0020] Furthermore, the first totem pole circuit includes transistor V1, transistor V2, and resistor R1.

[0021] The collector of transistor V1 is connected to the power supply VCC. The base of transistor V1 is connected to the first input terminal Vi1, one end of the resistor R1, and the base of transistor V2. The emitter of transistor V1 is connected to the collector of transistor V2 as the output terminal of the first totem pole circuit. The emitter of transistor V2 is connected to the second reference ground, and the other end of the resistor R1 is connected to the second reference ground.

[0022] The transistor V1 is an NPN transistor.

[0023] The transistor V2 is a PNP type transistor.

[0024] Furthermore, the second totem pole circuit includes transistor V3, transistor V4, and resistor R2; The collector of transistor V3 is connected to the power supply VCC. The base of transistor V3 is connected to the second input terminal Vi2, one end of resistor R2, and the base of transistor V4. The emitter of transistor V3 is connected to the collector of transistor V4 as the output terminal of the second totem pole circuit. The emitter of transistor V4 is connected to the second reference ground, and the other end of resistor R2 is connected to the second reference ground.

[0025] The transistor V3 is an NPN transistor.

[0026] The transistor V4 is a PNP type transistor.

[0027] Furthermore, the magnetically isolated transmission circuit includes a DC blocking capacitor C1, a transformer T1, a diode D1, and a diode D2.

[0028] The transformer T1 includes a primary winding Np, a secondary winding Ns1, and a secondary winding Ns2.

[0029] One end of the DC blocking capacitor C1 is connected to the output terminal of the first totem pole circuit, and the other end of the DC blocking capacitor C1 is connected to the same-name terminal of the primary winding Np. The opposite-name terminal of the primary winding Np is connected to the output terminal of the second totem pole circuit. The same-name terminal of the secondary winding Ns1 is connected to the cathode of the diode D2 and the input terminal of the first signal adjustment circuit. The opposite-name terminal of the secondary winding Ns1 is connected to the cathode of the diode D1 and the input terminal of the second signal adjustment circuit. The anode of the diode D1 is connected to the first reference ground, and the anode of the diode D2 is connected to the first reference ground.

[0030] Furthermore, the first signal adjustment circuit includes diode D3, resistor R3, resistor R4, resistor R5, capacitor C2, capacitor C3, and transistor V5.

[0031] The anode of diode D3 is connected to one end of resistor R4, one end of resistor R5, and the corresponding terminal of secondary winding Ns1. The cathode of diode D3 is connected to one end of resistor R3. The other end of resistor R3 is connected to the emitter of transistor V5, one end of capacitor C3, and the first output terminal Vo1. The other end of resistor R4 is connected to one end of capacitor C2 and the base of transistor V5. The other end of resistor R5 is connected to the other end of capacitor C2. The collector of transistor V5 is connected to the first reference ground, and the other end of capacitor C3 is connected to the first reference ground.

[0032] The transistor V5 is a PNP type transistor.

[0033] Furthermore, the second signal adjustment circuit includes diode D4, resistors R6, R7, and R8, capacitors C4 and C5, and transistor V6.

[0034] The anode of diode D4 is connected to one end of resistor R7, one end of resistor R8, and the opposite terminal of secondary winding Ns1. The cathode of diode D4 is connected to one end of resistor R6. The other end of resistor R6 is connected to the emitter of transistor V6, one end of capacitor C5, and the second output terminal Vo2. The other end of resistor R7 is connected to one end of capacitor C4 and the base of transistor V6. The other end of resistor R8 is connected to the other end of capacitor C4. The collector of transistor V6 is connected to the first reference ground, and the other end of capacitor C5 is connected to the first reference ground.

[0035] The transistor V6 is a PNP type transistor.

[0036] Furthermore, the power supply circuit includes diode D5, diode D6, capacitor C6, and capacitor C7. The anode of diode D5 is connected to the cathode of diode D6 and the same-name terminal of the secondary winding Ns2, respectively. The cathode of diode D5 is connected to one end of capacitor C6 and the third output terminal Vo3, respectively. The anode of diode D6 is connected to the first reference ground. The other end of capacitor C6 is connected to one end of capacitor C7 and the opposite-name terminal of the secondary winding Ns2, respectively. The other end of capacitor C7 is connected to the first reference ground.

[0037] In a second aspect of the present invention, a method for operating the above-described self-powered dual-path complementary magnetic isolation drive circuit is also disclosed.

[0038] Specifically, the method includes: S1, Enhanced Load Capacity The two complementary PWM signals are enhanced and processed by the first totem pole circuit and the second totem pole circuit respectively before being sent to the magnetically isolated transmission circuit.

[0039] S2, isolated transmission and signal following The magnetic isolation transmission circuit isolates and transmits the two PWM signals. After isolation and transmission, the two signals are adjusted by the first signal adjustment circuit and the second signal adjustment circuit respectively, and then output to follow the two complementary PWM signals in real time.

[0040] S3, Isolated self-powered The first totem pole circuit and the second totem pole circuit provide power supply current to the power supply circuit. The power supply circuit performs voltage doubler rectification on the power supply current to provide DC voltage to the bridge driver chip to achieve isolated self-powered operation.

[0041] Furthermore, the enhanced load-bearing capacity includes: The first input terminal Vi1 and the second input terminal Vi2 are two complementary PWM signals, which are enhanced and processed by the first totem pole circuit and the second totem pole circuit respectively before being sent to the magnetic isolation transmission circuit.

[0042] Furthermore, the isolated transmission and signal following include: When the first input terminal Vi1 is high, transistor V1 in the first totem pole circuit is turned on, transistor V2 is turned off, transistor V3 in the second totem pole circuit is turned off, and transistor V4 is turned on. The voltage of the primary winding Np of transformer T1 is positive at the top and negative at the bottom. The voltage induced in the secondary winding Ns1 of transformer T1 is also positive at the top and negative at the bottom. At this time, diodes D1 and D3 are turned on, and diodes D2 and D4 are turned off. The PWM signal of the first input terminal Vi1 is sent to the bridge driver chip through the first signal adjustment circuit. Resistor R3 and capacitor C3 form an RC charging network to adjust the rising edge of the input signal of the first input terminal Vi1. Transistor V5, resistor R4, resistor R5 and capacitor C2 form a fast discharge circuit. When the input signal of the first input terminal Vi1 becomes low, it provides a fast discharge circuit for the input signal of the first input terminal Vi1, ensuring that the output signal of the first output terminal Vo1 follows the falling edge of the input signal of the first input terminal Vi1.

[0043] When the second input terminal Vi2 is high, transistor V1 in the first totem pole circuit is turned off, transistor V2 is turned on, transistor V3 in the second totem pole circuit is turned on, and transistor V4 is turned off. The voltage of the primary winding Np of transformer T1 is negative at the top and positive at the bottom. The voltage induced in the secondary winding Ns1 of transformer T1 is also negative at the top and positive at the bottom. At this time, diodes D2 and D4 are turned on, and diodes D1 and D3 are turned off. The PWM signal of the second input terminal Vi2 is sent to the bridge driver chip through the second signal adjustment circuit. Resistor R6 and capacitor C5 form an RC charging network to adjust the rising edge of the input signal of the second input terminal Vi2. Transistor V6, resistor R7, resistor R8 and capacitor C4 form a fast discharge circuit. When the input signal of the second input terminal Vi2 becomes low, it provides a fast discharge circuit for the input signal of the second input terminal Vi2, ensuring that the output signal of the second output terminal Vo2 follows the falling edge of the input signal of the second input terminal Vi2.

[0044] Furthermore, the isolated self-powered system includes: The voltage induced in the secondary winding Ns2 of transformer T1 is periodically positive and negative. After being rectified by the power supply circuit, the output voltage Vo3 provides the power supply voltage for the bridge driver chip. The power supply current required by the power supply circuit is provided by the totem pole driver circuit and the totem pole circuit. When the voltage of the secondary winding Ns2 of transformer T1 is positive at the top and negative at the bottom, diode D5 conducts. The first totem pole circuit charges capacitor C6 through diode D5 and supplies power to the bridge driver chip. When the voltage of the secondary winding Ns2 of transformer T1 is negative at the top and positive at the bottom, diode D6 conducts. The second totem pole circuit charges capacitor C7 through diode D6 and supplies power to the bridge driver chip. The power supply circuit constitutes a voltage doubler rectifier circuit for standby rectification. The power supply voltage output from the third output terminal Vo3 is the sum of the positive and negative values ​​of the induced voltage of the secondary winding Ns2 of transformer T1.

[0045] Compared with the prior art, the advantages of the present invention are: (1) While realizing the PWM signal isolation transmission function, the present invention can provide DC voltage to realize isolated self-powered power supply without the need for an additional isolated power supply, and has the advantages of simple circuit structure and low cost. By setting diodes D1 and D2 in the magnetic isolation transmission circuit, dual complementary PWM signals can be transmitted through a single winding on the secondary side; by setting a secondary totem pole structure (first totem pole circuit and second totem pole circuit), primary isolated self-powered power supply is realized, and the primary side does not need a single-ended power supply to provide power supply voltage for the bridge driver.

[0046] (2) This invention achieves isolated self-powered operation by setting up a first totem pole circuit and a second totem pole circuit to enhance the load-carrying capacity of the subsequent stage; and by setting up diodes D1 and D2, it achieves the transmission of dual complementary PWM signals through a single winding. Compared with the existing technical solutions, the primary stage does not require a separate power supply to provide power to the bridge driver, and realizes the transmission of dual complementary PWM signals through a single winding of the magnetic isolation transformer. Without increasing the winding of the magnetic isolation transformer, it can simultaneously achieve dual PWM signal transmission and isolated self-powered operation.

[0047] (3) This invention utilizes the enhanced load-carrying capacity of totem-pole circuits and combines them with magnetically isolated transmission circuits to achieve isolated self-powered bridge drivers. As DC / DC power supplies develop towards higher power density and higher integration, in existing technologies, both the primary and secondary power supply voltages of the DC / DC power supply are provided by an auxiliary power supply. This auxiliary power supply provides both primary and secondary power supply voltages simultaneously. During layout design, the power supply layout must consider both primary and secondary power supplies, often leading to difficulties in layout and routing. This situation is particularly prominent in high-reliability thick-film hybrid integrated DC / DC power supplies that can only be mounted in a single layer. The magnetically isolated self-powered circuit provided by this invention can effectively solve this problem. During layout design, the self-powered circuit can be placed near the bridge driver, which is more conducive to high-density integration.

[0048] (4) The present invention has strong functional expandability. By selecting different bridge drivers, it can drive a variety of power devices such as MOSFET, IGBT, and GaN. Furthermore, if the bridge driver is a dedicated radiation-resistant driver, the circuit can be applied to the field of radiation-resistant power supplies. Attached Figure Description

[0049] Figure 1 This is a typical application circuit diagram of TI's UCC21520; Figure 2 The diagram shows the magnetic isolation drive circuit in Chinese patent CN109742952B. Figure 3 This is a magnetically isolated drive circuit disclosed in the prior art; Figure 4-1 This is a schematic diagram of a self-powered dual-path complementary magnetic isolation drive circuit according to an embodiment of the present invention; Figure 4-2 This is an equivalent scheme one of the schematic diagrams of the self-powered dual-path complementary magnetic isolation drive circuit of this invention. Figure 4-3 This is the second equivalent scheme of the schematic diagram of the self-powered dual-path complementary magnetic isolation drive circuit of the present invention; Figure 5 The waveform diagrams are for key nodes in an embodiment of the present invention. Detailed Implementation

[0050] The present invention will be further described below with reference to the accompanying drawings: like Figure 1 The diagram shows a self-powered dual-path complementary magnetic isolation drive circuit. The circuit includes: a first totem pole circuit 1, a second totem pole circuit 2, a magnetic isolation transmission circuit 3, a first signal adjustment circuit 4, a second signal adjustment circuit 5, and a power supply circuit 6.

[0051] Specifically, the main function of the first totem-pole circuit 1 and the second totem-pole circuit 2 is to control the time-division multiplexing of transistors V1, V2, V3, and V4 by controlling the timing of the two complementary PWM signals at the first input terminal Vi1 and the second input terminal Vi2, providing a current path for the power supply VCC, and thus providing the required supply current for the isolated power supply voltage Vo3. The main function of the magnetic isolation transmission circuit 3 is to transfer energy to the power supply voltage Vo3 while realizing the isolated transmission of the complementary PWM signals. The main function of the first signal adjustment circuit 4 and the second signal adjustment circuit 5 is to realize that the output PWM signal follows the two complementary input PWM signals in real time, and at the same time, the rise and fall times of the output PWM signal can be modulated by adjusting the parameters. The main function of the power supply circuit 6 is to realize the voltage doubler rectification function, and the output voltage provides the power supply voltage for the bridge isolation driver. The first signal adjustment circuit 4 and the second signal adjustment circuit 5 are used to ensure that the output PWM signal follows the two complementary input PWM signals in real time; the output terminal of the power supply circuit 6 is connected to the third output terminal Vo3. This circuit is used to implement the voltage doubler rectification function to provide DC voltage for the bridge driver chip to achieve isolated self-powered operation.

[0052] The input terminal of the first totem pole circuit 1 is connected to the first PWM signal, and the output terminal is connected to the first input terminal of the magnetically isolated transmission circuit 3; the input terminal of the second totem pole circuit 2 is connected to the second PWM signal, and the output terminal is connected to the second input terminal of the magnetically isolated transmission circuit 3; the first output terminal of the magnetically isolated transmission circuit 3 is connected to the input terminal of the first signal adjustment circuit 4, and the second output terminal is connected to the input terminal of the second signal adjustment circuit 5; the power supply circuit 6 is used to provide the power supply voltage.

[0053] Furthermore, the circuit also includes a first input terminal Vi1, a second input terminal Vi2, a first output terminal Vo1, a second output terminal Vo2, and a third output terminal Vo3. The first input terminal Vi1 and the second input terminal Vi2 are respectively connected to two complementary PWM signals output by the PWM controller. The first PWM signal is input to the first totem pole circuit 1 via the first input terminal Vi1, and the second PWM signal is input to the second totem pole circuit 2 via the second input terminal Vi2. The first PWM signal and the second PWM signal are two complementary PWM signals output by the PWM controller. The two complementary PWM signals are sent to the magnetically isolated transmission circuit 3 after their load-carrying capacity is enhanced by the first totem pole circuit 1 and the second totem pole circuit 2, respectively. The magnetically isolated transmission circuit 3 is used for the isolated transmission of the two complementary PWM signals. The output terminal of the first signal adjustment circuit 4 is connected to the first output terminal Vo1, and the output terminal of the second signal adjustment circuit 5 is connected to the second output terminal Vo2. The first output terminal Vo1 and the second output terminal Vo2 are respectively connected to the two input terminals of the bridge driver chip.

[0054] Furthermore, the first totem pole circuit 1 includes transistors V1 and V2 and resistor R1. The collector of transistor V1 is connected to the power supply VCC, and the base of transistor V1 is connected to the first input terminal Vi1, one end of resistor R1, and the base of transistor V2. The emitter of transistor V1 is connected to the collector of transistor V2 as the output terminal of the first totem pole circuit 1. The emitter of transistor V2 is connected to the second reference ground, and the other end of resistor R1 is connected to the second reference ground. Transistor V1 is an NPN transistor, and transistor V2 is a PNP transistor.

[0055] Furthermore, the second totem pole circuit 2 includes transistors V3 and V4 and resistor R2. The collector of transistor V3 is connected to the power supply VCC. The base of transistor V3 is connected to the second input terminal Vi2, one end of resistor R2, and the base of transistor V4. The emitter of transistor V3 is connected to the collector of transistor V4 as the output terminal of the second totem pole circuit 2. The emitter of transistor V4 is connected to the second reference ground, and the other end of resistor R2 is connected to the second reference ground. Transistor V3 is an NPN transistor; transistor V4 is a PNP transistor.

[0056] Furthermore, the magnetically isolated transmission circuit 3 includes a DC blocking capacitor C1, a transformer T1, a diode D1, and a diode D2; the transformer T1 includes a primary winding Np, a secondary winding Ns1, and a secondary winding Ns2; one end of the DC blocking capacitor C1 is connected to the output terminal of the first totem pole circuit 1, the other end of the DC blocking capacitor C1 is connected to the same-name terminal of the primary winding Np, the opposite-name terminal of the primary winding Np is connected to the output terminal of the second totem pole circuit 2, the same-name terminal of the secondary winding Ns1 is connected to the cathode of the diode D2 and the input terminal of the first signal adjustment circuit 4, the opposite-name terminal of the secondary winding Ns1 is connected to the cathode of the diode D1 and the input terminal of the second signal adjustment circuit 5, the anode of the diode D1 is connected to the first reference ground, and the anode of the diode D2 is connected to the first reference ground.

[0057] Furthermore, the first signal adjustment circuit 4 includes a diode D3, resistors R3, R4, and R5, capacitors C2 and C3, and a transistor V5. The anode of the diode D3 is connected to one end of resistor R4, one end of resistor R5, and the corresponding terminal of the secondary winding Ns1. The cathode of the diode D3 is connected to one end of resistor R3. The other end of resistor R3 is connected to the emitter of transistor V5, one end of capacitor C3, and the first output terminal Vo1. The other end of resistor R4 is connected to one end of capacitor C2 and the base of transistor V5. The other end of resistor R5 is connected to the other end of capacitor C2. The collector of transistor V5 is connected to the first reference ground, and the other end of capacitor C3 is connected to the first reference ground. Transistor V5 is a PNP transistor.

[0058] Furthermore, the second signal adjustment circuit 5 includes a diode D4, resistors R6, R7, and R8, capacitors C4 and C5, and a transistor V6. The anode of the diode D4 is connected to one end of resistor R7, one end of resistor R8, and the opposite-named terminal of the secondary winding Ns1. The cathode of the diode D4 is connected to one end of resistor R6. The other end of resistor R6 is connected to the emitter of transistor V6, one end of capacitor C5, and the second output terminal Vo2. The other end of resistor R7 is connected to one end of capacitor C4 and the base of transistor V6. The other end of resistor R8 is connected to the other end of capacitor C4. The collector of transistor V6 is connected to the first reference ground, and the other end of capacitor C5 is connected to the first reference ground. Transistor V6 is a PNP transistor.

[0059] Furthermore, the power supply circuit 6 includes diode D5, diode D6, capacitor C6, and capacitor C7. The anode of diode D5 is connected to the cathode of diode D6 and the same-name terminal of the secondary winding Ns2, respectively. The cathode of diode D5 is connected to one end of capacitor C6 and the third output terminal Vo3, respectively. The anode of diode D6 is connected to the first reference ground. The other end of capacitor C6 is connected to one end of capacitor C7 and the opposite-name terminal of the secondary winding Ns2, respectively. The other end of capacitor C7 is connected to the first reference ground.

[0060] In a second aspect of the present invention, a method for operating the above-described self-powered dual-path complementary magnetic isolation drive circuit is also disclosed.

[0061] Specifically, the method includes: S1, Enhanced Load Capacity The two complementary PWM signals are enhanced and processed by the first totem pole circuit 1 and the second totem pole circuit 2 respectively before being sent to the magnetically isolated transmission circuit 3. S2, isolated transmission and signal following The magnetic isolation transmission circuit 3 isolates and transmits the two PWM signals. After isolation and transmission, the two signals are adjusted by the first signal adjustment circuit 4 and the second signal adjustment circuit respectively and then output, which follow the two complementary PWM signals in real time. S3, Isolated self-powered The first totem pole circuit 1 and the second totem pole circuit 2 provide power supply current to the power supply circuit 6. The power supply circuit 6 performs voltage doubler rectification on the power supply current to provide DC voltage to the bridge driver chip to achieve isolated self-powered operation.

[0062] Furthermore, the enhanced load-bearing capacity includes: The first input terminal Vi1 and the second input terminal Vi2 are two complementary PWM signals, which are enhanced and processed by the first totem pole circuit 1 and the second totem pole circuit 2 respectively before being sent to the magnetic isolation transmission circuit 3.

[0063] Furthermore, the isolated transmission and signal following include: When the first input terminal Vi1 is high, transistor V1 in the first totem pole circuit 1 is turned on and transistor V2 is turned off. Transistor V3 in the second totem pole circuit 2 is turned off and transistor V4 is turned on. The voltage of the primary winding Np of transformer T1 is positive at the top and negative at the bottom. The voltage induced in the secondary winding Ns1 of transformer T1 is also positive at the top and negative at the bottom. At this time, diodes D1 and D3 are turned on and diodes D2 and D4 are turned off. The PWM signal of the first input terminal Vi1 is sent to the bridge driver chip through the first signal adjustment circuit 4. Resistor R3 and capacitor C3 form an RC charging network to adjust the rising edge of the input signal of the first input terminal Vi1. Transistor V5, resistor R4, resistor R5 and capacitor C2 form a fast discharge circuit. When the input signal of the first input terminal Vi1 becomes low, it provides a fast discharge circuit for the input signal of the first input terminal Vi1, ensuring that the output signal of the first output terminal Vo1 follows the falling edge of the input signal of the first input terminal Vi1.

[0064] When the second input terminal Vi2 is high, transistor V1 in the first totem pole circuit 1 is turned off and transistor V2 is turned on. Transistor V3 in the second totem pole circuit 2 is turned on and transistor V4 is turned off. The voltage of the primary winding Np of transformer T1 is negative at the top and positive at the bottom. The voltage induced in the secondary winding Ns1 of transformer T1 is also negative at the top and positive at the bottom. At this time, diodes D2 and D4 are turned on and diodes D1 and D3 are turned off. The PWM signal of the second input terminal Vi2 is sent to the bridge driver chip through the second signal adjustment circuit 5. Resistor R6 and capacitor C4 form an RC charging network to adjust the rising edge of the input signal of the second input terminal Vi2. Transistor V6, resistor R7, resistor R8 and capacitor C5 form a fast discharge circuit. When the input signal of the second input terminal Vi2 becomes low, it provides a fast discharge circuit for the input signal of the second input terminal Vi2, ensuring that the output signal of the second output terminal Vo2 follows the falling edge of the input signal of the second input terminal Vi2.

[0065] Furthermore, the isolated self-powered system includes: The voltage induced in the secondary winding Ns2 of transformer T1 is periodically positive and negative. After being rectified by the power supply circuit 6, the output voltage Vo3 provides the power supply voltage for the bridge driver chip. The power supply current required by the power supply circuit 6 is provided by the totem pole driver circuit 1 and the totem pole circuit 2. When the voltage of the secondary winding Ns2 of transformer T1 is positive at the top and negative at the bottom, diode D5 conducts. The first totem pole circuit 1 charges capacitor C6 through diode D5 and supplies power to the bridge driver chip. When the voltage of the secondary winding Ns2 of transformer T1 is negative at the top and positive at the bottom, diode D6 conducts. The second totem pole circuit 2 charges capacitor C7 through diode D6 and supplies power to the bridge driver chip. The power supply circuit 6 forms a voltage doubler rectifier circuit for standby rectification. The power supply voltage output from the third output terminal Vo3 is the sum of the positive and negative values ​​of the induced voltage of the secondary winding Ns2 of transformer T1.

[0066] Figure 4-1 The bridge driver chip can be selected according to the different types of driving devices. For example, the IR2110 bridge driver can be selected to drive MOSFETs and IGBTs. If GaN devices need to be driven, a dedicated GaN bridge driver, such as the NCP51820, can be selected. Figure 4-2 This is an equivalent scheme one of the schematic diagrams of the self-powered dual-path complementary magnetic isolation drive circuit of this invention, and... Figure 4-1 The difference is that removing Figure 4-1 The diodes D1 and D2 in the circuit, the secondary side of the magnetic isolation transformer T1 adopts a three-winding structure, the secondary windings Ns1 and Ns2 realize dual-channel complementary PWM signal transmission, and the secondary winding Ns3 realizes isolated self-powered supply. Figure 4-3 This is the second equivalent scheme of the schematic diagram of the self-powered dual-path complementary magnetic isolation drive circuit of the present invention, and... Figure 4-1 The difference lies in the swapping of the same-name and different-name terminals of the secondary winding Ns2. Similar to... Figure 4-3 There are several different combinations of equivalent schemes for swapping the same-name terminals of transformer T1 winding. The working principles of these equivalent schemes are... Figure 4-1 The same applies, so I won't go into details here.

[0067] Figure 5 The waveform diagrams for key nodes in the embodiments of the present invention are as follows: Vi1 is the waveform of the first input terminal, Vi2 is the waveform of the second input terminal, ip is the waveform of the transformer primary current, Vp is the waveform of the transformer primary winding terminal voltage, Vo1 is the waveform of the first output terminal, Vo2 is the waveform of the second output terminal, and Vo3 is the waveform of the third output terminal.

[0068] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A self-powered dual-channel complementary magnetic isolation drive circuit, characterized in that, The driving circuit includes: a first totem pole circuit (1), a second totem pole circuit (2), a magnetic isolation transmission circuit (3), a first signal adjustment circuit (4), a second signal adjustment circuit (5), and a power supply circuit (6); The input terminal of the first totem pole circuit (1) is connected to the first PWM signal, and the output terminal is connected to the first input terminal of the magnetic isolation transmission circuit (3); The input terminal of the second totem pole circuit (2) is connected to the second PWM signal, and the output terminal is connected to the second input terminal of the magnetic isolation transmission circuit (3); The first output terminal of the magnetic isolation transmission circuit (3) is connected to the input terminal of the first signal adjustment circuit (4), and the second output terminal is connected to the input terminal of the second signal adjustment circuit (5). The power supply circuit (6) is used to provide the power supply voltage; The driving circuit also includes a first input terminal Vi1, a second input terminal Vi2, a first output terminal Vo1, a second output terminal Vo2, and a third output terminal Vo3; The first PWM signal is input to the first totem pole circuit (1) via the first input terminal Vi1, and the second PWM signal is input to the second totem pole circuit (2) via the second input terminal Vi2. The first PWM signal and the second PWM signal are two complementary PWM signals output by the PWM controller. The two complementary PWM signals are sent to the magnetic isolation transmission circuit (3) after the load-carrying capacity is enhanced by the first totem pole circuit (1) and the second totem pole circuit (2). The magnetic isolation transmission circuit (3) is used for the isolated transmission of two complementary PWM signals. The output terminal of the first signal adjustment circuit (4) is connected to the first output terminal Vo1, and the output terminal of the second signal adjustment circuit (5) is connected to the second output terminal Vo2; the first output terminal Vo1 and the second output terminal Vo2 are respectively connected to the two input terminals of the bridge driver chip; The first signal adjustment circuit (4) and the second signal adjustment circuit (5) are used to ensure that the output PWM signal follows the two complementary input PWM signals in real time. The output terminal of the power supply circuit (6) is connected to the third output terminal Vo3. The power supply circuit (6) is used to realize the voltage doubler rectification function and provide DC voltage for the bridge driver chip to realize isolated self-power supply.

2. The self-powered dual-path complementary magnetic isolation drive circuit according to claim 1, characterized in that, The first totem pole circuit (1) includes transistor V1, transistor V2 and resistor R1; The collector of transistor V1 is connected to the power supply VCC. The base of transistor V1 is connected to the first input terminal Vi1, one end of resistor R1, and the base of transistor V2. The emitter of transistor V1 is connected to the collector of transistor V2 as the output terminal of the first totem pole circuit (1). The emitter of transistor V2 is connected to the first reference ground, and the other end of resistor R1 is connected to the first reference ground. The transistor V1 is an NPN type transistor; The transistor V2 is a PNP type transistor.

3. The self-powered dual-path complementary magnetic isolation drive circuit according to claim 2, characterized in that, The second totem pole circuit (2) includes transistor V3, transistor V4 and resistor R2; The collector of transistor V3 is connected to the power supply VCC. The base of transistor V3 is connected to the second input terminal Vi2, one end of resistor R2, and the base of transistor V4. The emitter of transistor V3 is connected to the collector of transistor V4 as the output terminal of the second totem pole circuit (2). The emitter of transistor V4 is connected to the first reference ground, and the other end of resistor R2 is connected to the first reference ground. The transistor V3 is an NPN type transistor; The transistor V4 is a PNP type transistor.

4. The self-powered dual-path complementary magnetic isolation drive circuit according to claim 3, characterized in that, The magnetically isolated transmission circuit (3) includes a DC blocking capacitor C1, a transformer T1, a diode D1, and a diode D2; The transformer T1 includes a primary winding Np, a secondary winding Ns1, and a secondary winding Ns2; One end of the DC blocking capacitor C1 is connected to the output terminal of the first totem pole circuit (1), and the other end of the DC blocking capacitor C1 is connected to the same-name terminal of the primary winding Np. The opposite-name terminal of the primary winding Np is connected to the output terminal of the second totem pole circuit (2). The same-name terminal of the secondary winding Ns1 is connected to the cathode of the diode D2 and the input terminal of the first signal adjustment circuit (4). The opposite-name terminal of the secondary winding Ns1 is connected to the cathode of the diode D1 and the input terminal of the second signal adjustment circuit (5). The anode of the diode D1 is connected to the second reference ground, and the anode of the diode D2 is connected to the second reference ground.

5. The self-powered dual-path complementary magnetic isolation drive circuit according to claim 4, characterized in that, The first signal adjustment circuit (4) includes diode D3, resistor R3, resistor R4, resistor R5, capacitor C2, capacitor C3 and transistor V5; The anode of diode D3 is connected to one end of resistor R4, one end of resistor R5, and the same-name terminal of secondary winding Ns1. The cathode of diode D3 is connected to one end of resistor R3. The other end of resistor R3 is connected to the emitter of transistor V5, one end of capacitor C3, and the first output terminal Vo1. The other end of resistor R4 is connected to one end of capacitor C2 and the base of transistor V5. The other end of resistor R5 is connected to the other end of capacitor C2. The collector of transistor V5 is connected to the second reference ground. The other end of capacitor C3 is connected to the second reference ground. The transistor V5 is a PNP type transistor.

6. The self-powered dual-path complementary magnetic isolation drive circuit according to claim 5, characterized in that, The second signal adjustment circuit (5) includes diode D4, resistor R6, resistor R7, resistor R8, capacitor C4, capacitor C5 and transistor V6; The anode of diode D4 is connected to one end of resistor R7, one end of resistor R8, and the opposite terminal of secondary winding Ns1. The cathode of diode D4 is connected to one end of resistor R6. The other end of resistor R6 is connected to the emitter of transistor V6, one end of capacitor C5, and the second output terminal Vo2. The other end of resistor R7 is connected to one end of capacitor C4 and the base of transistor V6. The other end of resistor R8 is connected to the other end of capacitor C4. The collector of transistor V6 is connected to the second reference ground. The other end of capacitor C5 is connected to the second reference ground. The transistor V6 is a PNP type transistor.

7. The self-powered dual-path complementary magnetic isolation drive circuit according to claim 6, characterized in that, The power supply circuit (6) includes diode D5, diode D6, capacitor C6 and capacitor C7. The anode of diode D5 is connected to the cathode of diode D6 and the same-name terminal of secondary winding Ns2. The cathode of diode D5 is connected to one end of capacitor C6 and the third output terminal Vo3. The anode of diode D6 is connected to the second reference ground. The other end of capacitor C6 is connected to one end of capacitor C7 and the opposite-name terminal of secondary winding Ns2. The other end of capacitor C7 is connected to the second reference ground.

8. A method for operating the self-powered dual-path complementary magnetic isolation drive circuit according to claim 7, characterized in that, The method includes: S1, Enhanced Load Capacity The two complementary PWM signals are enhanced and loaded through the first totem pole circuit (1) and the second totem pole circuit (2) respectively, and then sent to the magnetic isolation transmission circuit (3). S2, isolated transmission and signal following The magnetic isolation transmission circuit (3) isolates and transmits two complementary PWM signals. After isolation and transmission, the two signals are adjusted by the first signal adjustment circuit (4) and the second signal adjustment circuit (5) respectively and then output, following the two complementary PWM signals in real time. S3, Isolated self-powered The first totem pole circuit (1) and the second totem pole circuit (2) provide power supply current to the power supply circuit (6). The power supply circuit (6) performs voltage doubler rectification on the power supply current to provide DC voltage to the bridge driver chip to achieve isolated self-power supply.

9. The working method according to claim 8, characterized in that, The enhanced load capacity includes: The first input terminal Vi1 and the second input terminal Vi2 are two complementary PWM signals, which are enhanced and processed by the first totem pole circuit (1) and the second totem pole circuit (2) respectively before being sent to the magnetic isolation transmission circuit (3). The isolated transmission and signal following include: When the first input terminal Vi1 is high, transistor V1 in the first totem pole circuit (1) is turned on and transistor V2 is turned off. Transistor V3 in the second totem pole circuit (2) is turned off and transistor V4 is turned on. The voltage of the primary winding Np of transformer T1 is positive at the top and negative at the bottom. The voltage induced by the secondary winding Ns1 of transformer T1 is also positive at the top and negative at the bottom. At this time, diodes D1 and D3 are turned on and diodes D2 and D4 are turned off. The PWM signal of the first input terminal Vi1 is sent to the bridge driver chip through the first signal adjustment circuit (4). Resistor R3 and capacitor C3 form an RC charging network to adjust the rising edge of the input signal of the first input terminal Vi1. Transistor V5, resistor R4, resistor R5 and capacitor C2 form a fast discharge circuit. When the input signal of the first input terminal Vi1 becomes low, it provides a fast discharge circuit for the output signal of the first output terminal Vo1, ensuring that the output signal of the first output terminal Vo1 follows the falling edge of the input signal of the first input terminal Vi1. When the second input terminal Vi2 is high, transistor V1 in the first totem pole circuit (1) is turned off and transistor V2 is turned on. Transistor V3 in the second totem pole circuit (2) is turned on and transistor V4 is turned off. The voltage of the primary winding Np of transformer T1 is negative at the top and positive at the bottom. The voltage induced by the secondary winding Ns1 of transformer T1 is also negative at the top and positive at the bottom. At this time, diodes D2 and D4 are turned on and diodes D1 and D3 are turned off. The PWM signal of the second input terminal Vi2 is sent to the bridge driver chip through the second signal adjustment circuit (5). Resistor R6 and capacitor C5 form an RC charging network to adjust the rising edge of the input signal of the second input terminal Vi2. Transistor V6, resistor R7, resistor R8 and capacitor C4 form a fast discharge circuit. When the input signal of the second input terminal Vi2 becomes low, it provides a fast discharge circuit for the output signal of the second output terminal Vo2, ensuring that the output signal of the second output terminal Vo2 follows the falling edge of the input signal of the second input terminal Vi2. The isolated self-powered system includes: The voltage induced by the secondary winding Ns2 of transformer T1 is periodically positive and negative. After being rectified by the power supply circuit (6), the output voltage Vo3 is provided to supply the bridge drive chip. The power supply current required by the power supply circuit (6) is provided by the first totem pole circuit (1) and the second totem pole circuit (2). When the voltage of the secondary winding Ns2 of transformer T1 is positive at the top and negative at the bottom, the diode D5 is turned on. The first totem pole circuit (1) charges the capacitor C6 through the diode D5 and supplies power to the bridge drive chip. When the voltage of the secondary winding Ns2 of transformer T1 is negative at the top and positive at the bottom, the diode D6 is turned on. The second totem pole circuit (2) charges the capacitor C7 through the diode D6 and supplies power to the bridge drive chip. The power supply circuit (6) constitutes a voltage doubler rectifier circuit and performs voltage doubler rectification. The power supply voltage output by the third output terminal Vo3 is the sum of the positive and negative values ​​of the induced voltage of the secondary winding Ns2 of transformer T1.

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