Low-ripple power conversion circuit, power supply device and test machine

Abstract

The utility model relates to a low-ripple power switching circuit, a power supply device and a test machine, the low-ripple power switching circuit comprises a Y capacitor, a transformer and a processing module, the first end of the Y capacitor is connected with a primary winding of the transformer, and the second end of the Y capacitor is connected with a grounding end; a primary winding of the transformer is connected with alternating current, a secondary winding of the transformer is connected with the processing module, the alternating current after voltage reduction is output to the processing module, and the processing module outputs direct current to a load. The primary winding of the transformer is connected with the Y capacitor, so that the ripple noise of alternating current transmitted to the secondary winding can be effectively reduced, and the output voltage is stabilized.

Description

Technical Field

[0001] This application relates to the field of semiconductor testing technology, and in particular to a low-ripple power conversion circuit, power supply device, and testing machine. Background Technology

[0002] Semiconductor automated testing refers to the use of Automatic Test Equipment (ATE) to inspect various parameters of the Device Under Test (DUT), eliminating defective products and controlling the quality of semiconductors before they leave the factory. The test equipment's resource boards need to convert AC power to DC power to supply the load. Traditional power supply modules use transformers to step down the input AC power before outputting DC power to the load. While traditional power supply modules use shielding layers around the transformer to reduce common-mode interference, this still fails to meet testing requirements, resulting in ripple noise in the output current. Utility Model Content

[0003] Therefore, it is necessary to provide a low-ripple power conversion circuit, power supply device, and tester that can reduce ripple noise to address the above problems.

[0004] The first aspect of this application provides a low-ripple power conversion circuit, including a Y capacitor, a transformer, and a processing module. The first end of the Y capacitor is connected to the primary winding of the transformer, and the second end of the Y capacitor is connected to the ground terminal. The primary winding of the transformer is connected to AC power, and the secondary winding of the transformer is connected to the processing module. The transformer outputs stepped-down AC power to the processing module, and the processing module outputs DC power to the load.

[0005] In one embodiment, the low-ripple power conversion circuit further includes an AC power supply connected to the primary winding of the transformer.

[0006] In one embodiment, the processing module includes a rectifier circuit connected to the secondary winding of the transformer and the load.

[0007] In one embodiment, the processing module further includes a power amplifier circuit, the rectifier circuit is connected to the power amplifier circuit, and the power amplifier circuit is connected to the load.

[0008] In one embodiment, the power amplifier circuit includes an operational amplifier, a sampling resistor, a subtractor, a first proportional amplifier, an adder, a second proportional amplifier, a switching switch, an integrator, and a digital-to-analog converter. The digital-to-analog converter is connected to the first input terminal of the operational amplifier. The power supply pin of the operational amplifier is connected to the rectifier circuit. The ground pin of the operational amplifier is connected to the ground terminal. The output pin of the operational amplifier is connected to the first terminal of the load through the sampling resistor. The subtractor is connected to both ends of the sampling resistor and to the switching switch through the first proportional amplifier. The adder is connected to the first and second terminals of the load and to the switching switch through the second proportional amplifier. The switching switch is connected to the integrator, and the integrator is connected to the second input terminal of the operational amplifier.

[0009] In one embodiment, the processing module further includes an energy storage capacitor, the first end of which is connected to the power supply pin of the rectifier circuit and the operational amplifier, and the second end of which is connected to the ground terminal.

[0010] In one embodiment, the rectifier circuit includes diodes D1, D2, D3, and D4. The anodes of diodes D1 and D2 are both connected to ground. The cathodes of diodes D1 and D3 are both connected to the first end of the secondary winding. The cathodes of diodes D2 and D4 are both connected to the second end of the secondary winding. The cathodes of diodes D3 and D4 are both connected to the power amplifier circuit.

[0011] In one embodiment, the transformer is a transformer in which the primary winding and the secondary winding are alternately wound.

[0012] A second aspect of this application provides a power supply device, including a load and the aforementioned low-ripple power conversion circuit.

[0013] A third aspect of this application provides a testing machine, including the power supply device described above.

[0014] The aforementioned low-ripple power conversion circuit, power supply device, and testing machine connect a Y capacitor to the primary winding of the transformer, which can effectively reduce the ripple noise transmitted from the AC power to the secondary winding, thereby stabilizing the output voltage. Attached Figure Description

[0015] Figure 1 This is a block diagram of a low-ripple power conversion circuit in one embodiment;

[0016] Figure 2 This is a schematic diagram of the primary and secondary windings of a transformer in one embodiment;

[0017] Figure 3 This is a circuit schematic of a low-ripple power conversion circuit in one embodiment;

[0018] Figure 4 This is an equivalent circuit diagram of a low-ripple power conversion circuit in one embodiment. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0021] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0022] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, operations, components, parts, or combinations thereof.

[0023] In one embodiment, such as Figure 1 As shown, a low-ripple power conversion circuit is provided, including a Y capacitor C1, a transformer T1, and a processing module 110. The first end of the Y capacitor C1 is connected to the primary winding of the transformer T1, and the second end of the Y capacitor C1 is connected to the ground terminal GND. The primary winding of the transformer T1 is connected to AC power AC Vin, and the secondary winding of the transformer T1 is connected to the processing module 110. The stepped-down AC power is output to the processing module 110, and the processing module 110 outputs DC power to the load R1.

[0024] The processing module 110, upon receiving the stepped-down AC power, can either rectify the AC power to obtain DC power as its internal power supply, and then supply DC power to the load R1 according to the input signal; or it can rectify the AC power and directly supply the obtained DC power to the load R1. The load R1 can be a controller or other device requiring power. The first end of the load R1 is connected to the processing module 110, and the second end of the load R1 can also be connected to the ground terminal GND. The capacitance value of the Y capacitor C1 is not unique and can be selected according to the actual needs of the scenario. Furthermore, the low-ripple power conversion circuit may also include an AC power supply 120, which is connected to the primary winding of the transformer T1 and outputs AC power AC Vin with a frequency of tens of kHz to the primary winding of the transformer T1.

[0025] The primary and secondary windings of transformer T1 can be wound separately or alternately. In this embodiment, as shown... Figure 2 As shown, transformer T1 is a transformer with its primary and secondary windings interleaved. Interleaving the primary and secondary windings reduces leakage inductance, thereby reducing losses and radiation.

[0026] The specific structure of the processing module 110 is not unique. In one embodiment, the processing module 110 includes a rectifier circuit connected to the secondary winding of the transformer T1 and the load R1. The rectifier circuit rectifies the stepped-down AC power to obtain DC power to supply power to the load R1. The rectifier circuit can be a full-bridge rectifier circuit or a half-bridge rectifier circuit; in this embodiment, the rectifier circuit is a full-bridge rectifier circuit.

[0027] Furthermore, such as Figure 3 As shown, the processing module 110 includes a rectifier circuit X1 and a power amplifier circuit 112. The rectifier circuit X1 is connected to the power amplifier circuit 112, and the power amplifier circuit 112 is connected to the load R1. The rectifier circuit X1 may include diodes D1, D2, D3, and D4. The anodes of diodes D1 and D2 are both connected to ground (GND). The cathodes of diodes D1 and D3 are both connected to the first terminal of the secondary winding. The cathodes of diodes D2 and D4 are both connected to the second terminal of the secondary winding. The cathodes of diodes D3 and D4 are both connected to the power amplifier circuit 112. The rectifier circuit X1 outputs DC power to supply the power amplifier circuit 112, and the power amplifier circuit 112 outputs DC power V+ of the required voltage value to supply the load R1, thus adapting to different power supply requirements.

[0028] like Figure 3As shown, the power amplifier circuit 112 specifically includes an operational amplifier U1, a sampling resistor Rs, a subtractor 21, a first proportional amplifier 22, an adder 23, a second proportional amplifier 24, a switching switch 25, an integrator 26, and a digital-to-analog converter (DAC). The DAC is connected to the first input terminal of the operational amplifier U1 and outputs an analog signal to the operational amplifier U1. The power supply pin of the operational amplifier U1 is connected to the rectifier circuit X1, and the ground pin of the operational amplifier U1 is connected to the ground terminal GND. The output pin of the operational amplifier U1 is connected to the first terminal of the load R1 through the sampling resistor Rs. The subtractor 21 is connected to both ends of the sampling resistor Rs and is connected to the switching switch 25 through the first proportional amplifier 22. The adder 23 is connected to the first and second terminals of the load R1 and is connected to the switching switch 25 through the second proportional amplifier 24. The switching switch 25 is connected to the integrator 26, and the integrator 26 is connected to the second input terminal of the operational amplifier U1. Here, MI+ and MI- are current sampling signals, and MV+ and MV- are voltage sampling signals across the load R1.

[0029] The operating mode of the power amplifier circuit 112 can be changed by altering the conduction state of the switch 25. When the switch 25 connects the first proportional amplifier 22 and the integrator 26, the power amplifier circuit 112 operates in FI (constant current) mode. The subtractor 21 subtracts the current sampling signal to obtain the voltage signal flowing through the sampling resistor Rs. The first proportional amplifier 22 amplifies the signal calculated by the subtractor 21. When the switch 25 connects the second proportional amplifier 24 and the integrator 26, the power amplifier circuit 112 operates in FV (constant voltage) mode. The adder 23 adds the voltage sampling signal to obtain the voltage signal across the load R1. The second proportional amplifier 24 amplifies the signal calculated by the adder 23. The integrator 26 integrates the signal input by the switch 25, and the processed signal is sent to the operational amplifier U1 to adjust the output voltage / current.

[0030] In addition, continue to refer to Figure 3 The processing module 110 may also include an energy storage capacitor C. O Energy storage capacitor C O The first terminal is connected to the power supply pins of the rectifier circuit X1 and the operational amplifier U1, and the energy storage capacitor C O The second end is connected to the ground terminal GND.

[0031] like Figure 4 The diagram shown is the equivalent circuit diagram of a low-ripple power conversion circuit, C sp C is the parasitic capacitance of the secondary winding to the primary winding of transformer T1. ps C is the parasitic capacitance between the primary winding and the secondary winding of transformer T1. GPC is the parasitic capacitance between the grounding terminal GND and the chassis (ground). OP This is the parasitic capacitance between the output of power amplifier circuit 112 and the chassis (ground). Without capacitor C1, the AC output AC Vin from AC power supply 120 passes through the parasitic capacitance C of transformer T1. ps With C sp The ripple transmitted to the secondary winding of transformer T1, after passing through rectifier circuit X1 and power amplifier circuit 112, results in a high AC frequency ripple between the output of power amplifier circuit 112 and ground terminal GND. Based on this, this application reduces the parasitic capacitance C of transformer T1 by connecting a suitable Y capacitor C1 in parallel across the primary and secondary windings. ps With C sp Parasitic capacitance C output by the processing module GP With C OP Since the Y capacitor C1 is small enough, the AC ripple transmitted to the secondary winding is absorbed by the Y capacitor C1, thereby reducing the ripple. The specific value of the Y capacitor C1 can be determined by actual testing according to the output ripple requirements.

[0032] In one embodiment, a power supply device is also provided, including a load and the aforementioned low-ripple power conversion circuit. The number of low-ripple power conversion circuits can be one or more. When there are multiple low-ripple power conversion circuits, each low-ripple power conversion circuit can supply power to its corresponding load.

[0033] In one embodiment, a testing machine is also provided, including the power supply device described above.

[0034] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0035] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A low-ripple power conversion circuit, characterized in that, The system includes a Y-capacitor, a transformer, and a processing module. The first end of the Y-capacitor is connected to the primary winding of the transformer, and the second end of the Y-capacitor is connected to the ground terminal. The primary winding of the transformer is connected to AC power, and the secondary winding of the transformer is connected to the processing module. The transformer outputs stepped-down AC power to the processing module, and the processing module outputs DC power to the load.

2. The circuit according to claim 1, characterized in that, It also includes an AC power supply connected to the primary winding of the transformer.

3. The circuit according to claim 2, characterized in that, The processing module includes a rectifier circuit, which is connected to the secondary winding of the transformer and the load.

4. The circuit according to claim 3, characterized in that, The processing module further includes a power amplifier circuit, the rectifier circuit is connected to the power amplifier circuit, and the power amplifier circuit is connected to the load.

5. The circuit according to claim 4, characterized in that, The power amplifier circuit includes an operational amplifier, a sampling resistor, a subtractor, a first proportional amplifier, an adder, a second proportional amplifier, a switching switch, an integrator, and a digital-to-analog converter. The digital-to-analog converter is connected to the first input terminal of the operational amplifier. The power supply pin of the operational amplifier is connected to the rectifier circuit. The ground pin of the operational amplifier is connected to the ground terminal. The output pin of the operational amplifier is connected to the first terminal of the load through the sampling resistor. The subtractor is connected to both ends of the sampling resistor and is connected to the switching switch through the first proportional amplifier. The adder is connected to the first and second terminals of the load and is connected to the switching switch through the second proportional amplifier. The switching switch is connected to the integrator, and the integrator is connected to the second input terminal of the operational amplifier.

6. The circuit according to claim 5, characterized in that, The processing module also includes an energy storage capacitor, the first end of which is connected to the power supply pin of the rectifier circuit and the operational amplifier, and the second end of which is connected to the ground terminal.

7. The circuit according to claim 4, characterized in that, The rectifier circuit includes diodes D1, D2, D3, and D4. The anodes of diodes D1 and D2 are both connected to ground. The cathodes of diodes D1 and D3 are both connected to the first end of the secondary winding. The cathodes of diodes D2 and D4 are both connected to the second end of the secondary winding. The cathodes of diodes D3 and D4 are both connected to the power amplifier circuit.

8. The circuit according to any one of claims 1-7, characterized in that, The transformer is a transformer in which the primary winding and the secondary winding are alternately wound.

9. A power supply device, characterized in that, Includes a load and the low-ripple power conversion circuit as described in any one of claims 1-8.

10. A testing machine, characterized in that, Includes the power supply device as described in claim 9.

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