Anti-overshoot circuit of power supply and control method

Abstract

The anti-overshoot circuit is applied to the output end of the power supply, the power supply comprises an output capacitor, the total capacity of the output capacitor is not larger than 60 nf, the anti-overshoot circuit further comprises an energy storage device, a discharging circuit and a control circuit, the output capacitor and the energy storage device are connected to form a charging loop, the energy storage device is connected with the discharging circuit, and the discharging circuit is connected with the control circuit. The control circuit is connected with the discharging circuit. The total capacity of the output capacitor is not larger than 60 nf, the rapid response of the output voltage of the power supply can be met, the energy storage device does not participate in the main power output of the power supply, the effect of delaying the change of the output voltage is achieved, when the output voltage is overcharged, the energy storage device is charged through a charging loop formed by the output capacitor and the energy storage device, and the energy storage device is charged. The discharge loop releases electric quantity for the energy storage device, so that output voltage overshoot is restrained, loop response can meet the upper limit value of the output voltage, and the direct-current magnetron sputtering power source outputs fast response and can prevent the overshoot difficulty.

Description

Technical Field

[0001] The invention relates to a voltage stabilizing circuit for output of a magnetron sputtering power supply, and more specifically to an overshoot prevention circuit and a control method for the power supply. Background Art

[0002] High-power DC magnetron sputtering power supply is a very important core component in vacuum coating equipment, and plays a key role in providing high quality, high efficiency and high reliability. One of the difficulties in technical implementation is the requirement for adaptive control capability, which is very high. The power supply needs to have microsecond response capability. However, after the output voltage responds quickly, it is easy for the output voltage to overshoot when the load is switched. Summary of the invention

[0003] In order to overcome the problem that after the output voltage of the existing power supply responds quickly, the output voltage easily overshoots when the load is switched, the present invention provides an anti-overshoot circuit and control method of a power supply.

[0004] The technical solution of the present invention is as follows:

[0005] A power supply overshoot prevention circuit is applied to the output end of the power supply, the power supply includes an output capacitor, the total capacity of the output capacitor is not more than 60nf, the overshoot prevention circuit also includes an energy storage device, a discharge circuit and a control circuit, the output capacitor is connected to the energy storage device to form a charging loop, the energy storage device is connected to the discharge circuit, and the control circuit is connected to the discharge circuit to control the opening and closing of the discharge circuit.

[0006] According to the above-mentioned solution of the present invention, a diode is provided between the output capacitor and the energy storage device, the output capacitor is connected to the positive electrode of the diode, and the negative electrode of the diode is connected to the energy storage device.

[0007] According to the above-mentioned solution of the present invention, the discharge circuit includes an energy dissipation device and a first switch device, the energy dissipation device is connected to the energy storage device, and the energy dissipation device is connected to the first switch device.

[0008] According to the above-mentioned scheme of the present invention, the control circuit includes a second switching device and a control signal terminal, the second switching device is connected to the first switching device and is connected to the control signal terminal, and the second switching device controls the conduction and cutoff of the first switching device through the control signal input to the control signal terminal.

[0009] According to the above scheme of the present invention, the first switching device is the sixth MOS tube Q6, the second switching device is an optocoupler, the energy consumption devices are in two groups, one end of the energy consumption devices in one group is connected to the drain of the sixth MOS tube Q6, and the other end is connected to one end of the energy storage device, one end of the energy consumption devices in the other group is connected to the gate of the sixth MOS tube Q6, and the other end is connected to one end of the energy storage device, the source of the sixth MOS tube Q6 is connected to the other end of the energy storage device, the third pin of the optocoupler is connected to the source of the sixth MOS tube Q6, and the fourth pin of the optocoupler is connected to the gate of the sixth MOS tube Q6.

[0010] According to the above scheme of the present invention, the control circuit also includes a seventh resistor R7, an eighth resistor R8, a seventh transistor Q7 and a ninth resistor R9, the first pin of the optocoupler is connected to one end of the seventh resistor R7, the second pin of the optocoupler, the other end of the seventh resistor R7 and one end of the eighth resistor R8 are interconnected, the other end of the eighth resistor R8 is connected to the collector of the seventh transistor Q7, the two ends of the ninth resistor R9 are respectively connected to the base and emitter of the seventh transistor, and the base of the seventh transistor is connected to the control signal CONTR-DSP.

[0011] According to the present invention of the above scheme, the energy dissipation device is a resistor.

[0012] According to the above scheme of the present invention, the control circuit further includes an eighth capacitor C8 and a voltage regulator diode, one end of the eighth capacitor C8 is connected to the gate of the sixth MOS tube Q6, the other end of the eighth capacitor C8 is connected to the source of the sixth MOS tube Q6, one end of the voltage regulator diode is connected to the gate of the sixth MOS tube Q6, and the other end of the voltage regulator diode is connected to the source of the sixth MOS tube Q6.

[0013] According to the present invention of the above scheme, the energy storage device is an energy storage capacitor.

[0014] According to the above scheme of the present invention, the power supply includes an LLC circuit and a full-bridge rectifier circuit, the LLC circuit is connected to the full-bridge rectifier circuit, and the full-bridge rectifier circuit is the energy storage device.

[0015] A power supply overshoot prevention control method includes: when the output voltage is normal, a control circuit controls a discharge circuit to close, and the voltage of an energy storage device is maintained consistent with the output voltage; when the output voltage overshoots, the control circuit controls the discharge circuit to open, an output capacitor is connected to the energy storage device to form a charging loop, the output capacitor discharges to charge the energy storage device, and the discharge circuit discharges the energy storage device.

[0016] According to the above scheme of the present invention, the discharge circuit includes an energy-consuming device, a first switching device, a second switching device and a control signal terminal, the energy-consuming device is connected to the energy storage device, and the energy-consuming device is connected to the first switching device, the second switching device is connected to the first switching device and is connected to the control signal terminal, and the second switching device controls the conduction and cutoff of the first switching device through the control signal input to the control signal terminal.

[0017] The present invention according to the above scheme has the beneficial effect that the total capacity of the output capacitor of the present invention is not more than 60nf, which can meet the rapid response of the output voltage of the power supply, and the energy storage device does not participate in the main power output of the power supply, which plays a role in delaying the change of the output voltage. When the output voltage overshoots, the charging circuit composed of the output capacitor and the energy storage device charges the energy storage device, and the discharge circuit releases electricity for the energy storage device, thereby suppressing the output voltage overshoot, so that the loop response can meet the upper limit value of the output voltage, and realize the rapid response of the DC magnetron sputtering power supply output while preventing the difficulty of overshoot. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a circuit schematic diagram of the present invention;

[0019] Figure 2 It is a schematic diagram of the circuit structure of the present invention.

[0020] In the drawings, the reference numerals are as follows:

[0021] 10. Power supply; 11. Output capacitor; 20. Energy storage device; 30. Discharge circuit; 40. Control circuit. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0023] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices. Terms such as "disposed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "bottom", etc. are based on the directions or positions shown in the drawings, which are only for the convenience of description and cannot be understood as limitations on the present technical solution.

[0024] It should be noted that high-power DC magnetron sputtering power supply is a very important core component in vacuum coating equipment, and plays a key role in providing high quality, high efficiency and high reliability. One of the difficulties in technical implementation is the very high requirements for adaptive control capabilities, and the power supply must have microsecond response capabilities. However, after the output voltage responds quickly, when the load is switched, the output voltage is easy to overshoot.

[0025] Since the DC magnetron sputtering power supply has a wide output voltage range, one of which is in the range of 300Vdc-1000Vdc. In order to achieve a fast response of the output voltage in microseconds, the capacitor at the output end of the power supply needs to have low storage energy, less than 1mJ for every 1kW output. For a 30kW power supply, the output capacitance needs to be less than 60nf. In order to meet this application environment, a circuit is designed that can achieve voltage regulation and prevent output overshoot during load switching.

[0026] like Figure 1-Figure 2 As shown, this embodiment provides an overshoot prevention circuit for a power supply, the total capacity of the output capacitor 11 is not greater than 60nf, which can meet the rapid response of the output voltage of the power supply 10, and the energy storage device 20 does not participate in the main power output of the power supply 10, which plays a role in delaying the change of the output voltage. When the output voltage overshoots, the charging circuit formed by the output capacitor 11 and the energy storage device 20 charges the energy storage device 20, and the discharge circuit releases electricity for the energy storage device 20, thereby suppressing the output voltage overshoot, so that the loop response can meet the upper limit value of the output voltage, and the DC magnetron sputtering power supply 10 can achieve rapid output response and prevent overshoot difficulties.

[0027] The anti-overshoot circuit of the power supply is applied to the output end of the power supply 10. The power supply 10 includes an output capacitor 11. The total capacity of the output capacitor 11 is not more than 60nf. The anti-overshoot circuit also includes an energy storage device 20, a discharge circuit 30 and a control circuit 40. The output capacitor 11 is connected to the energy storage device 20 to form a charging loop, the energy storage device 20 is connected to the discharge circuit 30, and the control circuit 40 is connected to the discharge circuit 30 to control the opening and closing of the discharge circuit 30.

[0028] In one embodiment, a diode is provided between the output capacitor 11 and the energy storage device 20, the output capacitor 11 is connected to the anode of the diode, and the cathode of the diode is connected to the energy storage device 20. The diode is a fourth diode D4, one end of the output capacitor 11 is connected to the anode of the fourth diode D4, the cathode of the fourth diode D4 is connected to one end of the energy storage device 20, and the other end of the energy storage device 20 is connected to the other end of the output capacitor 11. When the output voltage overshoots, the output capacitor 11, the fourth diode D4 and the energy storage device 20 form a charging loop to suppress the output voltage overshoot so that the loop response can meet the upper limit value of the output voltage.

[0029] In one embodiment, the discharge circuit 30 includes an energy dissipation device and a first switch device, the energy dissipation device is connected to the energy storage device 20, and the energy dissipation device is connected to the first switch device.

[0030] The control circuit 40 includes a second switch device and a control signal terminal. The second switch device is connected to the first switch device and to the control signal terminal. The second switch device controls the conduction and cutoff of the first switch device through a control signal input to the control signal terminal.

[0031] Specifically, the first switching device is the sixth MOS tube Q6, the second switching device is an optocoupler, the energy storage device 20 is an energy storage capacitor, and the energy consumption devices are two groups, one end of one group of energy consumption devices is connected to the drain of the sixth MOS tube Q6, and the other end is connected to one end of the energy storage device 20, one end of the other group of energy consumption devices is connected to the gate of the sixth MOS tube Q6, and the other end is connected to one end of the energy storage device 20, the source of the sixth MOS tube Q6 is connected to the other end of the energy storage device 20, the third pin of the optocoupler is connected to the source of the sixth MOS tube Q6, and the fourth pin of the optocoupler is connected to the gate of the sixth MOS tube Q6.

[0032] The control signal end is the control signal CONTR-DSP. The control circuit 40 also includes a seventh resistor R7, an eighth resistor R8, a seventh transistor Q7 and a ninth resistor R9, a first pin of the optocoupler is connected to one end of the seventh resistor R7, a second pin of the optocoupler, the other end of the seventh resistor R7 and one end of the eighth resistor R8 are interconnected, the other end of the eighth resistor R8 is connected to the collector of the seventh transistor Q7, two ends of the ninth resistor R9 are respectively connected to the base and emitter of the seventh transistor, and the base of the seventh transistor is connected to the control signal CONTR-DSP.

[0033] The sixth MOS transistor Q6 and the optical coupler discharge the energy storage device 20. When working in a normal steady state, the control signal CONTR-DSP outputs a high level, controls the optical coupler U1 to be turned on, the sixth MOS transistor Q6 does not work, and the voltage on the energy storage capacitor is maintained consistent with the output voltage; when shutting down or the output voltage is adjusted from a high voltage to a low voltage, the control signal CONTR-DSP outputs a low level, the optical coupler is not turned on, and the sixth MOS transistor Q6 is driven to be turned on by another group of energy consumption devices (a first resistor R1, a second resistor R2 and a third resistor R3, the first resistor R1, the second resistor R2 and the third resistor R3 are connected in series in sequence), and the energy on the energy storage capacitor is discharged through a loop formed by a group of energy consumption devices (a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are connected in series in sequence) and the sixth MOS transistor Q6.

[0034] In one embodiment, the control circuit 40 further includes an eighth capacitor C8 and a voltage regulator diode, one end of the eighth capacitor C8 is connected to the gate of the sixth MOS tube Q6, the other end of the eighth capacitor C8 is connected to the source of the sixth MOS tube Q6, one end of the voltage regulator diode is connected to the gate of the sixth MOS tube Q6, and the other end of the voltage regulator diode is connected to the source of the sixth MOS tube Q6.

[0035] In one embodiment, the power supply 10 includes an LLC circuit and a full-bridge rectifier circuit, the LLC circuit is connected to the full-bridge rectifier circuit, and the full-bridge rectifier circuit has an energy storage device 20. The first MOS tube Q1, the second MOS tube Q2, the third MOS tube Q3, the fourth MOS tube Q4, the first capacitor C1, the first inductor L1, and the T1-A device constitute the LLC circuit, the first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 constitute the secondary full-bridge rectifier circuit, the second capacitor C2, the third capacitor C3 are the output capacitor 11, and the seventh diode D7 is the main output anti-backflow diode, and the above devices constitute a complete main power circuit. In order to meet the fast response of the output voltage, the second capacitor C2 and the third capacitor C3 are the output capacitor 11, and the total capacity of the constituted can only be less than 60nf.

[0036] The present embodiment provides an overshoot prevention control method for a power supply 10, comprising: when the output voltage is normal, the control circuit 40 controls the discharge circuit 30 to be closed, and the voltage of the energy storage device 20 is maintained consistent with the output voltage; when the output voltage overshoots, the control circuit 40 controls the discharge circuit 30 to be opened, the output capacitor 11 is connected to the energy storage device 20 to form a charging loop, the output capacitor 11 discharges to charge the energy storage device 20, and the discharge circuit 30 discharges the energy storage device 20.

[0037] In this embodiment, the discharge circuit 30 includes an energy-consuming device, a first switching device, a second switching device and a control signal terminal. The energy-consuming device is connected to the energy storage device 20, and the energy-consuming device is connected to the first switching device. The second switching device is connected to the first switching device and is connected to the control signal terminal. The second switching device controls the conduction and cutoff of the first switching device through the control signal input to the control signal terminal.

[0038] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

[0039] The above is an exemplary description of the present invention in conjunction with the accompanying drawings. It is obvious that the implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made by adopting the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A power supply overshoot prevention circuit, applied to the output end of the power supply, the power supply including an output capacitor, characterized in that: The total capacity of the output capacitor is no more than 60nf. The anti-overshoot circuit also includes an energy storage device, a discharge circuit and a control circuit. The output capacitor is connected to the energy storage device to form a charging loop, the energy storage device is connected to the discharge circuit, and the control circuit is connected to the discharge circuit to control the opening and closing of the discharge circuit.

2. The anti-overshoot circuit of a power supply according to claim 1, characterized in that: A diode is provided between the output capacitor and the energy storage device, the output capacitor is connected to the anode of the diode, and the cathode of the diode is connected to the energy storage device.

3. A power supply overshoot prevention circuit according to claim 1 or 2, characterized in that: The discharge circuit includes an energy dissipation device and a first switch device. The energy dissipation device is connected to the energy storage device, and the energy dissipation device is connected to the first switch device.

4. The power supply overshoot prevention circuit according to claim 3, characterized in that: The control circuit includes a second switch device and a control signal terminal. The second switch device is connected to the first switch device and to the control signal terminal. The second switch device controls the conduction and cutoff of the first switch device through a control signal input to the control signal terminal.

5. The power supply overshoot prevention circuit according to claim 4, characterized in that: The first switching device is the sixth MOS tube Q6, the second switching device is an optocoupler, the energy consumption devices are in two groups, one end of the energy consumption devices in one group is connected to the drain of the sixth MOS tube Q6, and the other end is connected to one end of the energy storage device, one end of the energy consumption devices in the other group is connected to the gate of the sixth MOS tube Q6, and the other end is connected to one end of the energy storage device, the source of the sixth MOS tube Q6 is connected to the other end of the energy storage device, the third pin of the optocoupler is connected to the source of the sixth MOS tube Q6, and the fourth pin of the optocoupler is connected to the gate of the sixth MOS tube Q6.

6. The power supply overshoot prevention circuit according to claim 5, characterized in that: The control circuit also includes a seventh resistor R7, an eighth resistor R8, a seventh transistor Q7 and a ninth resistor R9, the first pin of the optocoupler is connected to one end of the seventh resistor R7, the second pin of the optocoupler, the other end of the seventh resistor R7 and one end of the eighth resistor R8 are interconnected, the other end of the eighth resistor R8 is connected to the collector of the seventh transistor Q7, the two ends of the ninth resistor R9 are respectively connected to the base and emitter of the seventh transistor, and the base of the seventh transistor is connected to the control signal CONTR-DSP.

7. A power supply overshoot prevention circuit according to claim 4, 5 or 6, characterized in that: The energy dissipation device is a resistor.

8. A power supply overshoot prevention circuit according to claim 4, 5 or 6, characterized in that: The control circuit also includes an eighth capacitor C8 and a voltage regulator diode, one end of the eighth capacitor C8 is connected to the gate of the sixth MOS tube Q6, the other end of the eighth capacitor C8 is connected to the source of the sixth MOS tube Q6, one end of the voltage regulator diode is connected to the gate of the sixth MOS tube Q6, and the other end of the voltage regulator diode is connected to the source of the sixth MOS tube Q6.

9. A power supply overshoot prevention control method, characterized in that: include: The output voltage is normal, the control circuit controls the discharge circuit to close, and the voltage of the energy storage device is maintained consistent with the output voltage; When the output voltage overshoots, the control circuit controls the discharge circuit to open, the output capacitor is connected to the energy storage device to form a charging loop, the output capacitor discharges to charge the energy storage device, and the discharge circuit discharges the energy storage device.

10. The power supply overshoot prevention control method according to claim 9, characterized in that: The discharge circuit includes an energy-consuming device, a first switching device, a second switching device and a control signal terminal. The energy-consuming device is connected to the energy storage device, and the energy-consuming device is connected to the first switching device. The second switching device is connected to the first switching device and is connected to the control signal terminal. The second switching device controls the conduction and cutoff of the first switching device through the control signal input to the control signal terminal.

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