A source-sink mode implementation in a digital source meter and a circuit switching method thereof

Abstract

This invention discloses a source-well mode implementation and circuit switching method in a digital source meter. First, the AC power supply is converted to DC power greater than 250V by a PFC (Power Factor Correction) circuit. Then, it is output through a two-stage composite voltage regulator circuit: the first stage is a programmable composite method of switching regulation and linear regulation, and the second stage is a source / well circuit. A comparator compares the output with a preset threshold, and the logic control circuit generates a drive signal accordingly to control the on / off state of the corresponding power MOSFET combination, thereby achieving the switching between source and well modes. This allows for precise output of (source mode) voltage or current, simultaneous measurement of (well mode) current or voltage, and fast, smooth, and overshoot-free automatic or programmable switching between source and well modes.

Description

Technical Field

[0001] This invention relates to digital source tables, and more particularly to a source-sink mode implementation in a digital source table and a method for switching its circuit. Background Technology

[0002] A digital source meter is a sophisticated, comprehensive testing instrument that can accurately output (source mode) voltage or current while simultaneously measuring (sink mode) current or voltage.

[0003] Traditional digital source meters rely on mechanical relays or simple electronic switches when switching between source (output power) and sink (absorb power) modes. This results in problems such as slow switching speed, voltage / current overshoot or glitches, and limited relay lifespan. Existing technology

[0004] Existing source-sink mode switching schemes in digital source meters mostly employ hysteresis control based on voltage comparators. This method determines the operating mode by monitoring the output voltage and comparing it with a preset reference voltage threshold. However, this method suffers from slow response speed due to the propagation delay inherent in the comparator and the need for a large hysteresis window to suppress noise. During mode switching, the power control loop needs to re-establish stability, which can easily lead to output voltage overshoot. Slow switching can also render the signal ineffective during the transition period.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a source-sink mode implementation in a digital source table and a method for switching its circuit, so as to solve the above-mentioned technical problems existing in the prior art.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A source-sink mode implementation in a digital source table and its circuit switching method, comprising:

[0009] First, the AC power supply is converted into DC power greater than 250V through the PFC power factor correction circuit.

[0010] Then, the output is obtained after passing through a two-stage composite voltage regulator circuit:

[0011] The first stage is a programmable composite method of switching regulation and linear regulation. Based on the absolute value of the programmable signal setpoint, it generates a preliminary regulated voltage / current unipolar output, which is greater than the voltage drop generated by each subsequent stage.

[0012] The second stage is the source / sink circuit, which achieves linear regulated output based on the final set value and the sampling result of the sampling circuit.

[0013] A push-pull circuit is used as the polarity switching circuit for the source / well circuit.

[0014] Compared with the prior art, the source-sink mode implementation and circuit switching method of the digital source meter provided by the present invention can be used in the switching between source mode and sink mode in the digital source meter, realizing the accurate output of (source mode) voltage or current in the source meter, while simultaneously measuring (sink mode) current or voltage, and realizing fast, smooth, and overshoot-free automatic or programmable switching between source mode and sink mode. Attached Figure Description

[0015] Figure 1 This is the source mode circuit of an embodiment of the present invention;

[0016] Figure 2 This is a well-mode circuit according to an embodiment of the present invention;

[0017] Figure 3 This is a polarity switching circuit according to an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them, and do not constitute a limitation on the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0019] First, the following explanations are provided for the terms that may be used in this article:

[0020] The terms “including,” “contains,” “comprising,” “having,” or other similar semantic descriptions shall be interpreted as non-exclusive inclusion.

[0021] The term "composed of" excludes any technical features not expressly listed. When used in a claim, it closes the claim to exclude all technical features other than those expressly listed, except for associated conventional impurities. If the term appears only in a clause of a claim, it limits the claim to the elements expressly listed in that clause; elements recited in other clauses are not excluded from the overall claim.

[0022] The technical solution provided by this invention will be described in detail below. Contents not described in detail in the embodiments of this invention are prior art known to those skilled in the art. Where specific conditions are not specified in the embodiments of this invention, they shall be performed according to conventional conditions in the art or conditions recommended by the manufacturer. Reagents or instruments used in the embodiments of this invention whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0023] like Figures 1 to 3 As shown, a source-sink mode implementation and its circuit switching method in a digital source table include:

[0024] First, the AC power supply is converted into DC power greater than 250V through the PFC power factor correction circuit.

[0025] Then, the output is obtained after passing through a two-stage composite voltage regulator circuit:

[0026] The first stage is a programmable composite method of switching regulation and linear regulation. Based on the absolute value of the programmable signal setpoint, it generates a preliminary regulated voltage / current unipolar output, which is greater than the voltage drop generated by each subsequent stage.

[0027] The second stage is the source / sink circuit, which achieves linear regulated output based on the final set value and the sampling result of the sampling circuit.

[0028] A push-pull circuit is used as the polarity switching circuit for the source / well circuit.

[0029] The polarity switching circuit monitors the voltage or current flowing into / out of the device under test in real time, compares it with a preset threshold through a comparator, and the logic control circuit generates a drive signal accordingly to control the conduction and cutoff of the corresponding power MOSFET combination, thereby realizing the switching between source mode and sink mode.

[0030] The source / well circuit switches the source / well output and compensates for errors in subsequent stages, thereby achieving a precise 4-quadrant source / well output.

[0031] The polarity switching circuit changes the unidirectional output of the source / well circuit to a bidirectional source / well output according to the control signal, ultimately achieving 4-quadrant testing.

[0032] When the source is operating in waveform output mode, the two-stage composite voltage / current regulator circuit will output a pre-regulated voltage signal. The digital waveform output by the FPGA is synthesized into a waveform signal through a waveform DAC, which controls the source / sink circuit to generate waveform output.

[0033] In summary, the source-sink mode implementation and circuit switching method of the digital source meter in this embodiment of the invention can accurately output (source mode) voltage or current, while simultaneously measuring (sink mode) current or voltage, and achieve fast, smooth, and overshoot-free automatic or programmable switching between source and sink modes. This solves the problems of traditional digital source meters that rely on mechanical relays or simple electronic switches for source and sink mode switching, resulting in slow switching speeds, voltage / current overshoots or glitches, and limited relay lifespan.

[0034] To more clearly demonstrate the technical solution and its effects provided by the present invention, the following detailed description of the source-sink mode implementation and circuit switching method in the digital source table provided by the present invention is given by specific embodiments.

[0035] Example 1

[0036] like Figures 1 to 3 As shown:

[0037] When the output is in source mode, the output design block diagram is as follows: Figure 1 As shown; when the output is in sink mode, the output design block diagram is as follows. Figure 2 As shown;

[0038] First, the AC power supply (100V~250V, 50Hz~60Hz) is converted to DC power (greater than 250V) by a PFC power factor correction circuit. Then, it passes through a two-stage composite voltage regulator circuit for precise output. The first stage is a programmable composite method of switching regulation and linear regulation. Based on the absolute value of the programmable signal (set value), it generates a preliminary regulated voltage / current output (unipolar), which is greater than the voltage drop generated by subsequent stages. The second stage is a source / sink circuit, which achieves the second stage of linear regulated output based on the final set value and the sampling results of the sampling circuit.

[0039] A push-pull circuit is used to implement the source / well circuit and polarity switching circuit, such as Figure 3 :

[0040] When the source is operating in waveform output mode, the two-stage composite voltage / current regulator circuit will output a pre-regulated voltage signal. The digital waveform output by the FPGA is synthesized into a waveform signal through a waveform DAC, which controls the source / sink circuit to generate waveform output.

[0041] The present invention discloses a source-sink mode implementation and circuit switching method in a digital source meter, which can monitor the voltage or current flowing into / out of the device under test in real time. By comparing the voltage with a preset threshold through a comparator, the logic control circuit generates a drive signal to control the conduction and cutoff of the corresponding power MOSFET combination, thereby realizing fast, smooth, and overshoot-free automatic or programmable switching between source mode and sink mode.

[0042] This invention significantly improves testing efficiency and protects precision devices under test, making it particularly suitable for scenarios requiring rapid dynamic load changes, such as semiconductor device characteristic analysis and power management chip testing. This method has already been used in a four-quadrant precision programmable power supply designed by the project team. Its advantages include fast response, relatively low technical difficulty, and minimal waveform output distortion.

[0043] The main function of the source / well circuit is to switch the source / well output and compensate for the errors of subsequent stages, so as to achieve the source / well output of the accurate 4-quadrant source module.

[0044] The main function of the polarity switching circuit is to change the unidirectional output of the source / well circuit to a bidirectional source / well output according to the control signal, so as to achieve 4-quadrant testing.

[0045] This invention enables the accurate output (source mode) voltage or current from the source meter, while simultaneously measuring (sink mode) current or voltage, and achieves fast, smooth, and overshoot-free automatic or programmable switching between source mode and sink mode.

[0046] Key technical points of this invention:

[0047] 1. This invention protects the source mode circuit and sink mode circuit structure of the digital source table and the control relationship between the circuits.

[0048] 2. The pre-protection polarity switching circuit structure and the control relationship between circuits in this invention.

[0049] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. The information disclosed in the background section is intended only to enhance the understanding of the overall background technology of the present invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art.

Claims

1. A source-sink mode implementation in a digital source table and its circuit switching method, characterized in that, include: First, the AC power supply is converted into DC power greater than 250V through the PFC power factor correction circuit. Then, the output is obtained after passing through a two-stage composite voltage regulator circuit: The first stage is a programmable composite method of switching regulation and linear regulation. Based on the absolute value of the programmable signal setpoint, it generates a preliminary regulated voltage / current unipolar output, which is greater than the voltage drop generated by each subsequent stage. The second stage is the source / sink circuit, which achieves linear regulated output based on the final set value and the sampling result of the sampling circuit. A push-pull circuit is used as the polarity switching circuit for the source / well circuit.

2. The source-sink mode implementation and circuit switching method in the digital source table according to claim 1, characterized in that, The polarity switching circuit monitors the voltage or current flowing into / out of the device under test in real time, compares it with a preset threshold through a comparator, and the logic control circuit generates a drive signal accordingly to control the conduction and cutoff of the corresponding power MOSFET combination, thereby realizing the switching between source mode and sink mode.

3. The source-sink mode implementation and circuit switching method in the digital source table according to claim 2, Its characteristics are: The source / well circuit switches the source / well output and compensates for errors in subsequent stages, thereby achieving a precise 4-quadrant source / well output. The polarity switching circuit changes the unidirectional output of the source / well circuit to a bidirectional source / well output according to the control signal, ultimately achieving 4-quadrant testing.

4. The source-sink mode implementation and circuit switching method of the digital source table according to claim 1, 2 or 3, characterized in that, When the source is operating in waveform output mode, the two-stage composite voltage / current regulator circuit will output a pre-regulated voltage signal. The digital waveform output by the FPGA is synthesized into a waveform signal through a waveform DAC, which controls the source / sink circuit to generate waveform output.

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