Isolation driving system

Abstract

The utility model discloses an isolation driving system, and relates to the technical field of isolation driving circuit design. Comprising a dual-power circuit and an optical coupling isolation driving circuit, and the output end of the dual-power circuit is electrically connected with the input end of the optical coupling isolation driving circuit; the dual-power circuit comprises a waveform generation module, a half-bridge driving module, a transformer isolation module and a rectification output module; the output end of the waveform generation module is electrically connected with the input end of the half-bridge driving module, the output end of the half-bridge driving module is electrically connected with the input end of the transformer isolation module, and the output end of the transformer isolation module is electrically connected with the input end of the rectification output module. According to the system provided by the utility model, in the process of realizing positive and negative isolation power supply output, the damage to a device caused by overlarge negative voltage can be effectively avoided, the effective dual-power-supply driving of the driving chip is ensured, the use efficiency of the chip is improved, and the positive and negative isolation power supply output cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of isolation drive system design, in particular to an isolation drive system. Background Art

[0002] A MOSFET driver is a circuit specifically used to drive a MOSFET. Its main functions include providing a gate drive signal to drive the MOSFET and providing electrical isolation.

[0003] Currently, existing MOSFET drivers are categorized as isolated and non-isolated types. Using isolated driver technology to control MOSFETs offers advantages such as electrical isolation, safety, signal stability, and enhanced anti-interference performance, while also flexibly meeting diverse application requirements.

[0004] However, some circuits cannot use non-isolated drivers due to the floating source potential of the MOSFET. In addition, the existing MOSFET driver structure cannot effectively avoid damage to the device caused by excessive negative voltage during the process of driving the MOSFET device, resulting in low efficiency of the driver chip in the MOSFET driver, which in turn leads to high cost of driving the MOSFET device. Utility Model Content

[0005] In order to overcome the problem in the prior art that the existing MOSFET driver structure and the process of driving the MOSFET device cannot effectively avoid the damage to the device caused by excessive negative voltage, resulting in low chip utilization efficiency in the MOSFET driver, the utility model proposes an isolated drive system that can adopt dual power supply drive in the process of driving the MOSFET device, effectively avoid the damage to the device caused by excessive negative voltage, improve the utilization efficiency of the chip in the isolated drive system, and effectively reduce the cost of driving the MOSFET device.

[0006] The purpose of this utility model is achieved by the following technical solutions:

[0007] An isolated drive system includes: a dual power supply circuit and an optocoupler isolation drive circuit, wherein the output end of the dual power supply circuit is electrically connected to the input end of the optocoupler isolation drive circuit; the dual power supply circuit includes a waveform generation module, a half-bridge drive module, a transformer isolation module and a rectifier output module; the output end of the waveform generation module is electrically connected to the input end of the half-bridge drive module, the output end of the half-bridge drive module is electrically connected to the input end of the transformer isolation module, and the output end of the transformer isolation module is electrically connected to the input end of the rectifier output module.

[0008] In the above technical solution, a waveform generation module is used as a signal generation source, and a half-bridge drive module is combined with a transformer isolation module and a rectifier output module to realize positive and negative isolated power supply output, which can improve the voltage isolation effect and can adjust the negative voltage during negative voltage shutdown. Combined with the optocoupler isolation drive circuit, dual power supply drive is realized, thereby effectively avoiding damage to the device caused by excessive negative voltage during the process of driving the MOSFET device, improving the utilization efficiency of the chip in the isolation drive system, and effectively reducing the cost of driving the MOSFET device.

[0009] Preferably, the waveform generating module includes a timer chip U1, a diode D1, a diode D2 and an RC charge and discharge unit, the positive electrode of the diode D1 is electrically connected to the negative electrode of the diode D2 and pin 7 of the timer chip U1, respectively, the negative electrode of the diode D1 is electrically connected to the positive electrode of the diode D2, pin 2 of the timer chip U1, and pin 6 of the timer chip U1, pin 1 of the timer chip U1 is grounded, pin 8 of the timer chip U1 is connected to the positive electrode of the power supply VCC, and the RC charge and discharge unit is electrically connected to the timer chip U1, diode D1, and diode D2, respectively.

[0010] Preferably, the RC charge and discharge unit includes a resistor R1, a resistor R3, a capacitor C12 and a capacitor C14; the first end of the resistor R1 is electrically connected to the positive electrode of the diode D1, the first end of the resistor R3 and the pin 7 of the timer chip U1, the second end of the resistor R1 is electrically connected to the negative electrode of the diode D2, the first end of the resistor R3 is electrically connected to the pin 7 of the timer chip U1, the second end of the resistor R3 is electrically connected to the pin 8 of the timer chip U1 and the pin 4 of the timer chip U1, the first end of the capacitor C12 is electrically connected to the pin 5 of the timer chip, the second end of the capacitor C12 is electrically connected to the second end of the capacitor C14 and the pin 1 of the timer chip, and the first end of the capacitor C14 is electrically connected to the negative electrode of the diode D1, the positive electrode of the diode D2, the pin 2 of the timer chip U1 and the pin 6 of the timer chip U1.

[0011] In the above technical solution, pins 6 and 7 of the timer chip U1 are connected, and diode D1, diode D2, resistor R1, resistor R3, capacitor C12 and capacitor C14 are connected to form a multi-resonant oscillation circuit for generating the required square wave signal and keeping the oscillation frequency and duty cycle unchanged.

[0012] Preferably, the half-bridge drive module includes a transistor Q1 and a transistor Q2; pin 3 of the timer chip U1 is electrically connected to the base of the transistor Q1 and the base of the transistor Q2, respectively, the emitter of the transistor Q1 is electrically connected to the emitter of the transistor Q2, the collector of the transistor Q1 is electrically connected to the second end of the capacitor C12, the second end of the capacitor C14, and pin 1 of the timer chip U1, respectively, and the collector of the transistor Q2 is electrically connected to pin 4 of the timer chip U1.

[0013] Preferably, the transformer isolation module includes a transformer L1, a DC blocking capacitor C2 and a DC blocking capacitor C15; the first end of the DC blocking capacitor C2 is electrically connected to the emitter of the transistor Q1 and the emitter of the transistor Q2, respectively, and the second end of the DC blocking capacitor C2 is electrically connected to the first end of the transformer L1; the second end of the transformer L1 is electrically connected to the collector of the transistor 1, and the third end of the transformer L1 is electrically connected to the first end of the DC blocking capacitor C15.

[0014] Preferably, the rectifier output module includes a diode D3, a diode D5, a diode D4, a capacitor C5, a capacitor C6 and a resistor R6; the cathode of the diode D3 is electrically connected to the second end of the capacitor C15 and the anode of the diode D5, respectively; the second end of the capacitor C6 is connected to the cathode of the voltage output terminal, and is electrically connected to the anode of the diode D3, the fourth end of the transformer L1, and the first end of the resistor R6; the first end of the capacitor C5 is connected to the anode of the voltage output terminal, and is electrically connected to the cathode of the diode D5; the cathode of the diode D4 is grounded, and is electrically connected to the second end of the capacitor C5 and the first end of the capacitor C6; and the anode of the diode D4 is electrically connected to the second end of the resistor R6.

[0015] Preferably, the optocoupler isolation drive circuit includes a drive chip U3 and a resistor R5; pin 8 of the drive chip U3 is electrically connected to the positive pole of the voltage output end of the rectifier output module, pin 5 of the drive chip U3 is electrically connected to the negative pole of the voltage output end of the rectifier output module, pin 6 of the drive chip U3 is electrically connected to pin 7 and connected to the output end of the optocoupler isolation drive circuit, pin 2 of the drive chip U3 is electrically connected to the first end of the resistor R5, the second end of the resistor R5 is electrically connected to the input end of the optocoupler isolation drive circuit, and pin 3 of the drive chip U3 is grounded.

[0016] Preferably, the dual power supply circuit is a dual power supply circuit composed of 555.

[0017] Preferably, the timer chip U1 is a 555 timer chip.

[0018] Preferably, the transistor Q1 is a PNP transistor, and the transistor Q2 is an NPN transistor.

[0019] In the above technical solution, an isolated dual-power supply circuit is designed using a 555 timer module. This dual-power supply circuit provides isolated power to the optocoupler isolation driver chip, combining the two into an isolated driver circuit module. The waveform generation module uses the 555 timer as a multivibrator to generate the required square wave signal while maintaining a constant oscillation frequency and duty cycle. An RC charge-discharge circuit is also used to form the multivibrator circuit. The half-bridge driver circuit utilizes PNP transistors Q1 and NPN transistors Q2 to form a common base and common emitter circuit. The transformer isolation module utilizes DC blocking capacitors C2 and C15 to effectively prevent magnetic saturation. The rectifier output module can output a positive voltage of +12V and a negative voltage of -3.3V. Connecting the output to ground via voltage divider resistor R6 and Zener diode D4 effectively prevents damage to the device caused by excessive negative voltage. The optocoupler isolation driver circuit module enables dual-power drive, improving chip utilization efficiency.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] The utility model proposes an isolated drive system, which adopts a waveform generation module as a signal generation source, and uses a half-bridge drive module in combination with a transformer isolation module and a rectifier output module to realize positive and negative isolated power supply output, which can improve the voltage isolation effect and can adjust the negative voltage during negative voltage shutdown. Combined with an optocoupler isolation drive circuit, dual power supply drive is realized, so that in the process of driving MOSFET devices, damage to the devices caused by excessive negative voltage can be effectively avoided, the use efficiency of the chips in the isolated drive system can be improved, and the cost of driving MOSFET devices can be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic structural diagram of an isolation drive system provided by an embodiment of the present utility model;

[0023] Figure 2 A schematic diagram of the structure of a dual power supply circuit composed of 555 provided in an embodiment of the present utility model;

[0024] Figure 3 This is a schematic diagram of the structure of the optocoupler isolation drive circuit provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0025] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be provided below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to facilitate a more thorough and comprehensive understanding of the disclosure of the present invention.

[0026] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of this invention are intended only to describe specific embodiments and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] Example:

[0029] An isolated drive system, see 1, comprises: a dual power supply circuit and an optocoupler isolation drive circuit, wherein the output end of the dual power supply circuit is electrically connected to the input end of the optocoupler isolation drive circuit; the dual power supply circuit comprises a waveform generation module, a half-bridge drive module, a transformer isolation module, and a rectifier output module; the output end of the waveform generation module is electrically connected to the input end of the half-bridge drive module, the output end of the half-bridge drive module is electrically connected to the input end of the transformer isolation module, and the output end of the transformer isolation module is electrically connected to the input end of the rectifier output module; wherein the dual power supply circuit is a dual power supply circuit composed of 555. The waveform generation module is used as a signal generation source, and the half-bridge drive module is combined with the transformer isolation module and the rectifier output module to achieve positive and negative isolated power output, which can improve voltage isolation and enable negative voltage adjustment during negative voltage shutdown. In combination with the optocoupler isolation drive circuit, dual power supply drive is achieved, effectively avoiding damage to the MOSFET device caused by excessive negative voltage during the process of driving the device, improving the chip utilization efficiency in the isolated drive system, and effectively reducing the cost of driving the MOSFET device.

[0030] As a preferred embodiment, see Figure 2The waveform generation module includes a timer chip U1, a diode D1, a diode D2, and an RC charge-discharge unit. The anode of the diode D1 is electrically connected to the cathode of the diode D2 and pin 7 of the timer chip U1, respectively. The cathode of the diode D1 is electrically connected to the anode of the diode D2, pin 2 of the timer chip U1, and pin 6 of the timer chip U1, respectively. Pin 1 of the timer chip U1 is grounded, and pin 8 of the timer chip U1 is connected to the positive power supply VCC. The RC charge-discharge unit is electrically connected to the timer chip U1, diode D1, and diode D2, respectively. The timer chip U1 is a 555 timer chip.

[0031] As a preferred embodiment, see Figure 2 The RC charge and discharge unit includes a resistor R1, a resistor R3, a capacitor C12 and a capacitor C14; the first end of the resistor R1 is electrically connected to the positive electrode of the diode D1, the first end of the resistor R3 and the pin 7 of the timer chip U1, the second end of the resistor R1 is electrically connected to the negative electrode of the diode D2, the first end of the resistor R3 is electrically connected to the pin 7 of the timer chip U1, the second end of the resistor R3 is electrically connected to the pin 8 of the timer chip U1 and the pin 4 of the timer chip U1, the first end of the capacitor C12 is electrically connected to the pin 5 of the timer chip, the second end of the capacitor C12 is electrically connected to the second end of the capacitor C14 and the pin 1 of the timer chip, the first end of the capacitor C14 is electrically connected to the negative electrode of the diode D1, the positive electrode of the diode D2, the pin 2 of the timer chip U1 and the pin 6 of the timer chip U1. Among them, pin 6 and pin 7 of the timer chip U1 are connected, and diode D1, diode D2, resistor R1, resistor R3, capacitor C12 and capacitor C14 are connected to form a multi-resonant oscillation circuit for generating the required square wave signal and keeping the oscillation frequency and duty cycle unchanged.

[0032] As a preferred embodiment, see Figure 2 The half-bridge driver module includes a transistor Q1 and a transistor Q2. Pin 3 of the timer chip U1 is electrically connected to the base of the transistor Q1 and the base of the transistor Q2, respectively. The emitter of the transistor Q1 is electrically connected to the emitter of the transistor Q2. The collector of the transistor Q1 is electrically connected to the second end of the capacitor C12, the second end of the capacitor C14, and pin 1 of the timer chip U1, respectively. The collector of the transistor Q2 is electrically connected to pin 4 of the timer chip U1. The transistor Q1 is a PNP transistor, and the transistor Q2 is an NPN transistor.

[0033] As a preferred embodiment, see Figure 2The transformer isolation module includes a transformer L1, a DC blocking capacitor C2 and a DC blocking capacitor C15; the first end of the DC blocking capacitor C2 is electrically connected to the emitter of the transistor Q1 and the emitter of the transistor Q2, respectively, and the second end of the DC blocking capacitor C2 is electrically connected to the first end of the transformer L1; the second end of the transformer L1 is electrically connected to the collector of the transistor 1, and the third end of the transformer L1 is electrically connected to the first end of the DC blocking capacitor C15.

[0034] As a preferred embodiment, see Figure 2 The rectifier output module includes a diode D3, a diode D5, a diode D4, a capacitor C5, a capacitor C6, and a resistor R6; the cathode of the diode D3 is electrically connected to the second end of the capacitor C15 and the anode of the diode D5, respectively; the second end of the capacitor C6 is connected to the cathode of the voltage output terminal, and is electrically connected to the anode of the diode D3, the fourth end of the transformer L1, and the first end of the resistor R6; the first end of the capacitor C5 is connected to the anode of the voltage output terminal and is electrically connected to the cathode of the diode D5; the cathode of the diode D4 is grounded, and is electrically connected to the second end of the capacitor C5 and the first end of the capacitor C6; and the anode of the diode D4 is electrically connected to the second end of the resistor R6.

[0035] As a preferred embodiment, see Figure 3 The optocoupler isolation drive circuit includes a driver chip U3 and a resistor R5; pin 8 of the driver chip U3 is electrically connected to the positive voltage output terminal of the rectifier output module, pin 5 of the driver chip U3 is electrically connected to the negative voltage output terminal of the rectifier output module, pin 6 of the driver chip U3 is electrically connected to pin 7 and connected to the output terminal of the optocoupler isolation drive circuit, pin 2 of the driver chip U3 is electrically connected to the first end of the resistor R5, and the second end of the resistor R5 is electrically connected to the input terminal of the optocoupler isolation drive circuit, and pin 3 of the driver chip U3 is grounded. In addition, the optocoupler isolation drive circuit also includes pin headers J1 and J3. Pin 2 of the driver chip U3 is electrically connected to the pin header J1 connection interface, and pin 3 of the driver chip U3 is electrically connected to the pin header J3 connection interface.

[0036] The operating principle of this utility model is to design an isolated dual-power supply circuit using a 555 timer module. This dual-power supply circuit provides isolated power to an optocoupler isolation driver chip, combining the two to form an isolated driver circuit module. The waveform generation module uses a 555 timer as a multivibrator to generate the required square wave signal while maintaining a constant oscillation frequency and duty cycle. An RC charge-discharge circuit is also used to form a multivibrator circuit. The half-bridge driver circuit utilizes PNP transistors Q1 and NPN transistors Q2 to form a common base and common emitter circuit. The transformer isolation module utilizes DC blocking capacitors C2 and C15 to effectively prevent magnetic saturation. The rectifier output module can output a positive voltage of +12V and a negative voltage of -3.3V. Connecting the output to ground via voltage divider resistor R6 and Zener diode D4 effectively prevents damage to the device caused by excessive negative voltage. The optocoupler isolation driver circuit module enables dual-power drive, improving chip utilization efficiency.

[0037] In the present invention, a square wave with a duty cycle of 50% is generated by a waveform generation module, which is driven by a half-bridge drive module, transformed by a transformer and a DC blocking capacitor, and then rectified and filtered by a rectifier output module to output positive and negative voltages to power the optocoupler isolation driver chip, thereby driving the MOSFET device to work.

[0038] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An isolation drive system, characterized in that: include: A dual power supply circuit and an optocoupler isolation drive circuit, wherein the output end of the dual power supply circuit is electrically connected to the input end of the optocoupler isolation drive circuit; the dual power supply circuit includes a waveform generating module, a half-bridge drive module, a transformer isolation module and a rectifier output module; the output end of the waveform generating module is electrically connected to the input end of the half-bridge drive module, the output end of the half-bridge drive module is electrically connected to the input end of the transformer isolation module, and the output end of the transformer isolation module is electrically connected to the input end of the rectifier output module.

2. The isolation drive system according to claim 1, characterized in that: The waveform generating module includes a timer chip U1, a diode D1, a diode D2 and an RC charge and discharge unit. The positive electrode of the diode D1 is electrically connected to the negative electrode of the diode D2 and pin 7 of the timer chip U1, respectively. The negative electrode of the diode D1 is electrically connected to the positive electrode of the diode D2, pin 2 of the timer chip U1 and pin 6 of the timer chip U1, respectively. Pin 1 of the timer chip U1 is grounded, and pin 8 of the timer chip U1 is connected to the positive electrode of the power supply VCC. The RC charge and discharge unit is electrically connected to the timer chip U1, diode D1 and diode D2, respectively.

3. The isolation drive system according to claim 2, characterized in that: The RC charge and discharge unit includes a resistor R1, a resistor R3, a capacitor C12 and a capacitor C14; the first end of the resistor R1 is electrically connected to the positive electrode of the diode D1, the first end of the resistor R3 and the pin 7 of the timer chip U1, the second end of the resistor R1 is electrically connected to the negative electrode of the diode D2, the first end of the resistor R3 is electrically connected to the pin 7 of the timer chip U1, the second end of the resistor R3 is electrically connected to the pin 8 of the timer chip U1 and the pin 4 of the timer chip U1, the first end of the capacitor C12 is electrically connected to the pin 5 of the timer chip, the second end of the capacitor C12 is electrically connected to the second end of the capacitor C14 and the pin 1 of the timer chip, and the first end of the capacitor C14 is electrically connected to the negative electrode of the diode D1, the positive electrode of the diode D2, the pin 2 of the timer chip U1 and the pin 6 of the timer chip U1.

4. The isolation drive system according to claim 3, characterized in that: The half-bridge drive module includes a transistor Q1 and a transistor Q2; pin 3 of the timer chip U1 is electrically connected to the base of the transistor Q1 and the base of the transistor Q2, respectively, the emitter of the transistor Q1 is electrically connected to the emitter of the transistor Q2, the collector of the transistor Q1 is electrically connected to the second end of the capacitor C12, the second end of the capacitor C14, and pin 1 of the timer chip U1, respectively, and the collector of the transistor Q2 is electrically connected to pin 4 of the timer chip U1.

5. The isolation drive system according to claim 4, characterized in that: The transformer isolation module includes a transformer L1, a DC blocking capacitor C2 and a DC blocking capacitor C15; the first end of the DC blocking capacitor C2 is electrically connected to the emitter of the transistor Q1 and the emitter of the transistor Q2, respectively, and the second end of the DC blocking capacitor C2 is electrically connected to the first end of the transformer L1; the second end of the transformer L1 is electrically connected to the collector of the transistor 1, and the third end of the transformer L1 is electrically connected to the first end of the DC blocking capacitor C15.

6. The isolation drive system according to claim 5, characterized in that: The rectifier output module includes a diode D3, a diode D4, a diode D5, a capacitor C5, a capacitor C6 and a resistor R6; the cathode of the diode D3 is electrically connected to the second end of the capacitor C15 and the anode of the diode D5, respectively; the second end of the capacitor C6 is connected to the cathode of the voltage output terminal, and is electrically connected to the anode of the diode D3, the fourth end of the transformer L1, and the first end of the resistor R6; the first end of the capacitor C5 is connected to the anode of the voltage output terminal and is electrically connected to the cathode of the diode D5; the cathode of the diode D4 is grounded, and is electrically connected to the second end of the capacitor C5 and the first end of the capacitor C6; and the anode of the diode D4 is electrically connected to the second end of the resistor R6.

7. The isolation drive system according to claim 6, characterized in that: The optocoupler isolation drive circuit includes a drive chip U3 and a resistor R5; pin 8 of the drive chip U3 is electrically connected to the positive pole of the voltage output end of the rectifier output module, pin 5 of the drive chip U3 is electrically connected to the negative pole of the voltage output end of the rectifier output module, pin 6 of the drive chip U3 is electrically connected to pin 7 and connected to the output end of the optocoupler isolation drive circuit, pin 2 of the drive chip U3 is electrically connected to the first end of the resistor R5, the second end of the resistor R5 is electrically connected to the input end of the optocoupler isolation drive circuit, and pin 3 of the drive chip U3 is grounded.

8. The isolation drive system according to claim 1, characterized in that: The dual power supply circuit is a dual power supply circuit composed of 555.

9. The isolation drive system according to claim 2, characterized in that: The timer chip U1 is a 555 timer chip.

10. The isolation drive system according to claim 4, wherein: The transistor Q1 is a PNP transistor, and the transistor Q2 is an NPN transistor.

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