Unbalanced power supply circuit and precision source meter

Abstract

This application discloses an unbalanced power supply circuit and a precision source meter. The unbalanced power supply circuit includes a positive power supply switching module, a negative power supply switching module, a low-voltage positive power supply, a high-voltage positive power supply, a low-voltage negative power supply, and a high-voltage negative power supply. When the input voltage VIN is higher than the positive voltage threshold, the positive power supply switching module is turned on, and the negative power supply switching module is turned off. The positive output voltage of the unbalanced power supply circuit is provided by the high-voltage positive power supply, and the negative output voltage is provided by the low-voltage negative power supply. When the input voltage VIN is lower than the negative voltage threshold, the negative power supply switching module is turned on, and the positive power supply switching module is turned off. The negative output voltage of the unbalanced power supply circuit is provided by the high-voltage negative power supply, and the positive output voltage is provided by the low-voltage positive power supply. When the input voltage VIN is between the positive and negative voltage thresholds, both the positive and negative power supply switching modules are turned off. The positive output voltage of the unbalanced power supply circuit is provided by the low-voltage positive power supply, and the negative output voltage is provided by the low-voltage negative power supply.

Description

Technical Field

[0001] This application relates to the field of circuit design, specifically to an unbalanced power supply circuit and a precision power meter. Background Technology

[0002] In existing precision source meters, operational amplifiers typically require stable and matched supply voltages to ensure the accuracy of signal measurements. Since the input signals processed by the source meter are bipolar, exceeding a certain range of the operational amplifier's power rails can easily lead to device damage or measurement distortion. To avoid this problem, existing technologies typically use high-voltage operational amplifiers to extend the input range; however, these devices often come with significant voltage noise and offset voltage, contradicting the precision source meter's requirements for low noise and high resolution. Another approach is to use a floating power supply, achieving a wide power range through multi-stage transformer modules; however, this solution is bulky and difficult to apply to multi-channel and high-density integrated source meter designs. Therefore, existing technologies face a dilemma in simultaneously achieving extended input / output range, reduced noise and offset, and improved integration. Utility Model Content

[0003] The purpose of this application is to provide an unbalanced power supply circuit and a precision source meter to solve the problems of insufficient or excessive power supply voltage, difficulty in achieving both low noise and low offset characteristics, large size of floating power supply design, and unfavorable high-density integration of operational amplifiers in existing precision source meters under wide bipolar input voltage.

[0004] To achieve the above objectives, this application discloses the following technical solution: The first aspect of this application provides an unbalanced power supply circuit, including a positive power supply switching module, a negative power supply switching module, a low-voltage positive power supply, a high-voltage positive power supply, a low-voltage negative power supply, and a high-voltage negative power supply. Both the positive power switching module and the negative power switching module are connected to the input voltage VIN. The positive power switching module is connected to the high-voltage positive power supply, and the negative power switching module is connected to the high-voltage negative power supply. The positive output terminal of the unbalanced power supply circuit is connected to the low-voltage positive power supply and the positive power switching module, respectively, and the negative output terminal of the unbalanced power supply circuit is connected to the low-voltage negative power supply and the negative power switching module, respectively. When the input voltage VIN is higher than the positive voltage threshold, the positive power supply switching module is turned on and the negative power supply switching module is turned off, so that the positive output voltage of the unbalanced power supply circuit is provided by the high voltage positive power supply and the negative output voltage of the unbalanced power supply circuit is provided by the low voltage negative power supply. When the input voltage VIN is lower than the negative voltage threshold, the negative power supply switching module is turned on and the positive power supply switching module is turned off, so that the negative output voltage of the unbalanced power supply circuit is provided by the high voltage negative power supply and the positive output voltage of the unbalanced power supply circuit is provided by the low voltage positive power supply. When the input voltage VIN is between the positive voltage threshold and the negative voltage threshold, both the positive power supply switching module and the negative power supply switching module are disconnected, so that the voltage at the positive output terminal of the unbalanced power supply circuit is provided by the low-voltage positive power supply, and the voltage at the negative output terminal is provided by the low-voltage negative power supply.

[0005] Optionally, the unbalanced power supply circuit further includes a first diode D1 and a second diode D2; The anode of the first diode D1 is connected to the low-voltage positive power supply, and the cathode of the first diode D1 is connected to the positive output terminal of the unbalanced power supply circuit. The cathode of the second diode D2 is connected to the low-voltage negative power supply, and the anode of the second diode D2 is connected to the negative output terminal of the unbalanced power supply circuit.

[0006] Optionally, the positive power supply switching module includes a first voltage detection unit and a first switching unit connected to each other, wherein the first switching unit is connected to the positive output terminal of the high voltage positive power supply and the unbalanced power supply circuit, respectively. The first voltage detection unit is configured to turn on the first switching unit when it detects that the input voltage VIN is higher than a positive voltage threshold.

[0007] Optionally, the negative power supply switching module includes a second voltage detection unit and a second switching unit connected to each other, wherein the second switching unit is connected to the negative output terminal of the high voltage negative power supply and the unbalanced power supply circuit, respectively. The second voltage detection unit is configured to turn on the second switching unit when it detects that the input voltage VIN is lower than the negative voltage threshold.

[0008] Optionally, the first voltage detection unit includes a first transistor Q1 and a third diode D3; The base of the first transistor Q1 is connected to the input voltage VIN, the emitter of the first transistor Q1 is grounded, and the collector of the first transistor Q1 is connected to the first switching unit. The anode of the third diode D3 is connected to the emitter of the first transistor Q1, and the cathode of the third diode D3 is connected to the base of the first transistor Q1.

[0009] Optionally, the first switching unit includes a first switching transistor M1 and a first resistor R1; The gate of the first switching transistor M1 is connected to the collector of the first transistor Q1, the source of the first switching transistor M1 is connected to the high voltage positive power supply, and the drain of the first switching transistor M1 is connected to the positive output terminal of the unbalanced power supply circuit. The first end of the first resistor R1 is connected to the gate of the first switch M1, and the second end of the first resistor R1 is connected to the source of the first switch M1.

[0010] Optionally, the first transistor Q1 is an NPN transistor, and the first switch M1 is a PMOS transistor.

[0011] Optionally, the second voltage detection unit includes a second transistor Q2 and a fourth diode D4; The base of the second transistor Q2 is connected to the input voltage VIN, the emitter of the second transistor Q2 is grounded, and the collector of the second transistor Q2 is connected to the second switching unit. The anode of the fourth diode D4 is connected to the emitter of the second transistor Q2, and the cathode of the fourth diode D4 is connected to the base of the second transistor Q2.

[0012] Optionally, the second switching unit includes a second switching transistor M2 and a second resistor R2; The gate of the second switching transistor M2 is connected to the collector of the second transistor Q2, the source of the second switching transistor M2 is connected to the high voltage negative power supply, and the drain of the second switching transistor M2 is connected to the negative output terminal of the unbalanced power supply circuit. The first end of the second resistor R2 is connected to the gate of the second switch M2, and the second end of the second resistor R2 is connected to the source of the second switch M2.

[0013] Optionally, the second transistor Q2 is a PNP transistor, and the second switch M2 is an NMOS transistor.

[0014] According to a second aspect of this application, a precision source meter is provided, comprising a power supply circuit, a signal conditioning circuit, and an output circuit connected in sequence. The power supply circuit is used to provide operating power to each circuit of the precision source meter; The signal conditioning circuit is used to generate and regulate voltage or current signals. The signal conditioning circuit includes an operational amplifier and an unbalanced power supply circuit. The positive output terminal of the unbalanced power supply circuit is connected to the positive power supply terminal of the operational amplifier, and the negative output terminal of the unbalanced power supply circuit is connected to the negative power supply terminal of the operational amplifier. It is used to switch the operating voltage of the operational amplifier according to the input voltage. The output circuit is connected to the device under test and is used to output the regulated voltage or current signal to the device under test.

[0015] Optionally, the signal conditioning circuit further includes an FPGA module and a power drive module; The FPGA module is connected to the power supply circuit and is used to receive external voltage and current commands and output control signals. The input terminal of the power drive module is connected to the FPGA module, and the output terminal is connected to the output circuit, used to generate voltage or current signals according to the control signal; The input terminal of the operational amplifier is connected to the power drive module, and the output terminal is connected to the FPGA module. It is used to acquire the voltage or current signal output by the power drive module in real time and feed it back to the FPGA module to realize closed-loop control of the voltage or current signal.

[0016] The unbalanced power supply circuit provided in this application, through the cooperation of a positive and negative power supply switching module and high and low voltage power supplies, achieves dynamic switching of the operational amplifier's power supply voltage in a precision source meter. When the input voltage amplitude exceeds a specific threshold, the high-voltage power supply automatically turns on to ensure the normal operation of the operational amplifier; when the input voltage amplitude is in the middle range, the low-voltage power supply provides a stable voltage, enabling the operational amplifier's power rail to dynamically adjust according to the output voltage range, thereby significantly reducing the voltage withstand requirements of the operational amplifier's power rail. This application not only facilitates modular implementation of the circuit but also enables integrated applications in high-density circuits, eliminating the need for traditional floating ground designs for output and power supplies, thus effectively saving space resources in circuit design.

[0017] Furthermore, through the coordinated operation of the voltage detection unit and the switching unit, precise control of the high-voltage turn-on timing is achieved. Simultaneously, the use of discrete components such as transistors, resistors, and diodes enhances the response speed and stability of the switching action. The positive and negative power supply switching transistors utilize PMOS and NMOS types, combined with current-limiting resistors and diode protection, improving the reliability of the switching process and preventing insufficient conduction or overvoltage. In addition, the low-voltage power supply, connected across the output terminal via a diode, ensures stable power supply to the operational amplifier within the intermediate amplitude range, guaranteeing power supply accuracy and system stability over a wide input range, while also improving the reliability and measurement performance of the precision source meter. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the principles of this application.

[0019] Figure 1 A structural block diagram of an unbalanced power supply circuit according to an embodiment of this application is shown; Figure 2 An unbalanced power supply circuit topology diagram according to one embodiment of this application is shown; Figure 3 The diagram shows the waveforms of the output voltage and input voltage of an unbalanced power supply circuit according to an embodiment of this application; Figure 4 A structural block diagram of a precision source table according to an embodiment of this application is shown. Detailed Implementation

[0020] 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.

[0021] It should be noted that references to "an embodiment," "embodiment," "example embodiment," etc., in this specification refer to the described embodiment including specific features, structures, or characteristics; however, not every embodiment must include these specific features, structures, or characteristics. Furthermore, such expressions do not refer to the same embodiment. Moreover, when describing specific features, structures, or characteristics in conjunction with embodiments, whether or not explicitly described, it is indicated that incorporating such features, structures, or characteristics into other embodiments is within the knowledge of those skilled in the art.

[0022] Furthermore, certain terms are used in the specification and subsequent claims to refer to specific components or parts. Those skilled in the art will understand that manufacturers may use different names or terms to refer to the same component or part. This specification and subsequent claims do not distinguish components or parts by differences in name, but rather by differences in function. The terms "comprising" and "including" used throughout the specification and subsequent claims are open-ended and should be interpreted as "including but not limited to." Additionally, the term "connection" here includes any direct and indirect electrical connection means. Indirect electrical connection means include connections made through other means.

[0023] Figure 1 A structural block diagram of an unbalanced power supply circuit according to an embodiment of this application is shown. Figure 1As shown, the unbalanced power supply circuit includes a positive power switching module 10, a negative power switching module 20, a low-voltage positive power supply, a high-voltage positive power supply, a low-voltage negative power supply, and a high-voltage negative power supply. Both the positive power switching module 10 and the negative power switching module 20 are connected to the input voltage VIN. The positive power switching module 10 is connected to the high-voltage positive power supply, and the negative power switching module 20 is connected to the high-voltage negative power supply. The positive output terminal of the unbalanced power supply circuit is connected to the low-voltage positive power supply and the positive power switching module 10, respectively, while the negative output terminal is connected to the low-voltage negative power supply and the negative power switching module 20, respectively. When the input voltage VIN is higher than the positive voltage threshold, the positive power switching module 10 is turned on, and the negative power switching module 20 is turned off, so that the positive output voltage of the unbalanced power supply circuit is provided by the high-voltage positive power supply, and the negative output voltage of the unbalanced power supply circuit is provided by the low-voltage negative power supply. When the input voltage VIN is below the negative voltage threshold, the negative power supply switching module 20 is turned on, and the positive power supply switching module 10 is turned off, so that the negative output voltage of the unbalanced power supply circuit is provided by the high-voltage negative power supply, and the positive output voltage of the unbalanced power supply circuit is provided by the low-voltage positive power supply. When the input voltage VIN is between the positive and negative voltage thresholds, both the positive power supply switching module 10 and the negative power supply switching module 20 are turned off, so that the positive output voltage of the unbalanced power supply circuit is provided by the low-voltage positive power supply, and the negative output voltage is provided by the low-voltage negative power supply.

[0024] According to the above embodiments, the dynamic switching of the operational amplifier's power supply voltage in the precision source meter is achieved through the cooperation of the positive and negative power supply switching module 20 and the high and low voltage power supplies. When the input voltage amplitude exceeds a specific threshold, the high voltage power supply automatically turns on to ensure the normal operation of the operational amplifier; when the input voltage amplitude is in the middle range, the low voltage power supply provides a stable voltage, enabling the operational amplifier's power rail to dynamically adjust with the output voltage range, thereby significantly reducing the voltage withstand requirements of the operational amplifier's power rail. This application not only facilitates modular implementation of the circuit but also enables integrated applications in high-density circuits, eliminating the need for traditional floating ground designs for output and power supplies, thus effectively saving space resources in circuit design.

[0025] Figure 2 An unbalanced power supply circuit topology diagram according to one embodiment of this application is shown. Figure 2 As shown, the unbalanced power supply circuit also includes a first diode D1 and a second diode D2. The anode of the first diode D1 is connected to the low-voltage positive power supply, and the cathode of the first diode D1 is connected to the positive output terminal of the unbalanced power supply circuit. The anode of the second diode D2 is connected to the low-voltage negative power supply, and the cathode of the second diode D2 is connected to the negative output terminal of the unbalanced power supply circuit.

[0026] In this embodiment, by connecting a first diode D1 across the positive output terminal of the unbalanced power supply circuit and a second diode D2 across the negative output terminal, a stable voltage can still be provided to the output terminal when the high voltage switching is not on. This ensures the normal operation of the circuit within the intermediate amplitude range, improving the continuity of power supply and the stability of the system. Furthermore, the first diode D1 and the second diode D2 effectively prevent current backflow from the low voltage power supply when the high voltage is on, avoiding any impact on the low voltage power supply, and simultaneously achieving automatic isolation between the high and low voltage power supplies.

[0027] In one embodiment, reference Figure 2 The positive power supply switching module 10 includes a first voltage detection unit 11 and a first switching unit 12 connected to each other. The first switching unit 12 is connected to the positive output terminal of the high voltage positive power supply and the unbalanced power supply circuit, respectively. The first voltage detection unit 11 is configured to turn on the first switching unit 12 when it detects that the input voltage VIN is higher than the positive voltage threshold.

[0028] In one embodiment, reference Figure 2 The negative power supply switching module 20 includes a second voltage detection unit 21 and a second switching unit 22 connected to each other. The second switching unit 22 is connected to the negative output terminal of the high-voltage negative power supply and the unbalanced power supply circuit, respectively. The second voltage detection unit 21 is configured to turn on the second switching unit 22 when it detects that the input voltage VIN is lower than the negative voltage threshold.

[0029] According to the above embodiments, when the amplitude of the input voltage VIN is detected to be higher than the positive voltage threshold and the input voltage VIN is a positive voltage, the first switching unit 12 is turned on and the second switching unit 22 is turned off. At this time, the positive output voltage of the unbalanced power supply circuit is provided by the high-voltage positive power supply, and the negative output voltage is provided by the low-voltage negative power supply. When the amplitude of the input voltage VIN is detected to be lower than the negative voltage threshold and the input voltage VIN is a negative voltage, the first switching unit 12 is turned off and the second switching unit 22 is turned on. At this time, the negative output voltage of the unbalanced power supply circuit is provided by the high-voltage negative power supply, and the positive output voltage is provided by the low-voltage positive power supply. When the amplitude of the input voltage VIN is detected to be between the negative voltage threshold and the positive voltage threshold, both the first switching unit 12 and the second switching unit 22 are turned off. At this time, the positive output voltage of the unbalanced power supply circuit is provided by the low-voltage positive power supply, and the negative output voltage is provided by the low-voltage negative power supply. This embodiment achieves stable power supply under different input voltage VIN amplitudes by dynamically switching between high and low voltage power supplies, avoiding the risk of insufficient power supply or overvoltage in the operational amplifier in the high or intermediate amplitude range, thereby improving the stability of the circuit and the measurement accuracy.

[0030] In one embodiment, reference Figure 2The first voltage detection unit 11 includes a first transistor Q1 and a third diode D3. The base of the first transistor Q1 is connected to the input voltage VIN, the emitter of the first transistor Q1 is grounded, and the collector of the first transistor Q1 is connected to the first switching unit. The anode of the third diode D3 is connected to the emitter of the first transistor Q1, and the cathode of the third diode D3 is connected to the base of the first transistor Q1.

[0031] In this embodiment, the third diode D3 is connected between the emitter and base of the first transistor Q1 to form emitter negative feedback, which limits the fluctuation of the base-emitter voltage of the first transistor Q1, thereby improving the stability and response accuracy of the first voltage detection unit 11 and ensuring that the first switching unit 12 can be accurately turned on or off when the input voltage VIN is close to the threshold, avoiding malfunctions caused by signal spikes or noise.

[0032] In one embodiment, reference Figure 2 The first voltage detection unit 11 also includes a third resistor R3, a fourth resistor R4, and a fifth resistor R5. The first terminal of the third resistor R3 is connected to the input voltage VIN, and the second terminal is connected to the base of the first transistor Q1. This protects the base of the first transistor Q1 and detects the current, ensuring reliable operation of the voltage detection unit under high input voltage. The first terminal of the fourth resistor R4 is connected to the emitter of the first transistor Q1, and the second terminal is grounded. This determines the emitter potential of the first transistor Q1, helping to form a stable base-emitter voltage. The first terminal of the fifth resistor R5 is connected to the collector of the first transistor Q1, and the second terminal is connected to the gate of the first switching transistor M1. This serves to level up and isolate the signal, ensuring that the first switching transistor M1 receives a stable control signal.

[0033] In one embodiment, reference Figure 2 The first switching unit 12 includes a first switching transistor M1 and a first resistor R1. The gate of the first switching transistor M1 is connected to the collector of the first transistor Q1 through a fifth resistor R5. The source of the first switching transistor M1 is connected to a high-voltage positive power supply, and the drain of the first switching transistor M1 is connected to the positive output terminal of the unbalanced power supply circuit. The first end of the first resistor R1 is connected to the gate of the first switching transistor M1, and the second end of the first resistor R1 is connected to the source of the first switching transistor M1.

[0034] In this embodiment, the first resistor R1 is connected in parallel between the source of the first switching transistor M1 and the control terminal to control the gate current of the first switching transistor M1 and enhance the conduction speed of the first switching transistor M1, while limiting the current peak value and improving the switching stability.

[0035] In one embodiment, the first transistor Q1 is an NPN transistor, and the first switching transistor M1 is a PMOS transistor.

[0036] In this embodiment, the first transistor Q1 is an NPN transistor, which can be turned on by applying a forward voltage to its base and is matched with the positive power supply voltage signal to realize high-level triggering logic. The first switching transistor M1 is a PMOS transistor, with its source connected to the high-voltage positive power supply. It turns on when the control terminal voltage drops, which can efficiently provide high-voltage positive power to the positive output terminal of the unbalanced power supply circuit. At the same time, it has low on-resistance and fast switching characteristics, making it suitable for high-voltage switching scenarios.

[0037] In one embodiment, reference Figure 2 The second voltage detection unit 21 includes a second transistor Q2 and a fourth diode D4. The base of the second transistor Q2 is connected to the input voltage VIN, the emitter of the second transistor Q2 is grounded, and the collector of the second transistor Q2 is connected to the second switching unit. The anode of the fourth diode D4 is connected to the emitter of the second transistor Q2, and the cathode of the fourth diode D4 is connected to the base of the second transistor Q2.

[0038] In one embodiment, reference Figure 2 The second voltage detection unit 21 also includes a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8. The first terminal of the sixth resistor R6 is connected to the input voltage VIN, and the second terminal is connected to the base of the second transistor Q2. The first terminal of the seventh resistor R7 is connected to the emitter of the second transistor Q2, and the second terminal is grounded. The first terminal of the eighth resistor R8 is connected to the collector of the second transistor Q2, and the second terminal is connected to the gate of the second switching transistor M2.

[0039] In one embodiment, reference Figure 2 The second switching unit 22 includes a second switching transistor M2 and a second resistor R2. The gate of the second switching transistor M2 is connected to the collector of the second transistor Q2 through an eighth resistor R8. The source of the second switching transistor M2 is connected to a high-voltage negative power supply, and the drain of the second switching transistor M2 is connected to the negative output terminal of the unbalanced power supply circuit. The first end of the second resistor R2 is connected to the gate of the second switching transistor M2, and the second end of the second resistor R2 is connected to the source of the second switching transistor M2.

[0040] The functions of the second resistor R2, the sixth resistor R6, the seventh resistor R7, and the eighth resistor R8 in the above embodiments correspond to the functions of the first resistor R1, the third resistor R3, the fourth resistor R4, and the fifth resistor R5 in the first voltage detection unit 11, respectively, and will not be elaborated further here.

[0041] In one embodiment, the second transistor Q2 is a PNP transistor, and the second switching transistor M2 is an NMOS transistor.

[0042] In this embodiment, the second transistor Q2 is a PNP transistor, which enables it to conduct when the base voltage is lower than the emitter voltage, thereby triggering the second switching unit 22 in a timely manner when the input voltage VIN is lower than the negative voltage threshold. The second switching transistor M2 is an NMOS transistor, with its source connected to the high-voltage negative power supply. It conducts when the control terminal voltage rises, efficiently outputting the high-voltage negative power supply to the circuit, while also possessing low on-resistance and fast response characteristics, thus ensuring the reliability and stability of negative voltage switching.

[0043] According to the above embodiment, when the input voltage VIN is higher than the positive voltage threshold, the emitter junction of the first transistor Q1 is forward biased and the reflector junction of the second transistor Q2 is reverse biased. Since the first transistor Q1 is NPN type and the second transistor Q2 is PNP type, and the first switch M1 is PMOS type and the second switch M2 is NMOS type, the first switch M1 is turned on and the second switch M2 is turned off. At this time, the positive output voltage of the unbalanced power supply circuit of this application is provided by the high voltage positive power supply and the negative output voltage is provided by the low voltage negative power supply.

[0044] When the input voltage VIN is lower than the negative voltage threshold, the emitter junction of the second transistor Q2 is forward biased, and the reflector junction of the first transistor Q1 is reverse biased. Since the first transistor Q1 is NPN and the second transistor Q2 is PNP, and the first switch M1 is PMOS and the second switch M2 is NMOS, the first switch M1 is off and the second switch M2 is on. At this time, the negative output voltage of the unbalanced power supply circuit of this application is provided by the high voltage negative power supply, and the positive output voltage is provided by the low voltage positive power supply.

[0045] When the input voltage VIN is between the negative and positive voltage thresholds, i.e., when the amplitude of the input voltage VIN is higher than the negative voltage threshold but lower than the positive voltage threshold, it is insufficient to forward bias the emitter junctions of the first transistor Q1 and the second transistor Q2. Therefore, both the first switch M1 and the second switch M2 are turned off. At this time, the positive output voltage of the unbalanced power supply circuit of this application is provided by the low-voltage positive power supply, and the negative output voltage is provided by the low-voltage negative power supply.

[0046] According to the above embodiments, precise control of the high-voltage turn-on timing is achieved through the coordinated action of the voltage detection unit and the switching unit. Simultaneously, the response speed and stability of the switching action are improved by incorporating discrete components such as transistors, resistors, and diodes. The positive and negative power supply switching transistors utilize PMOS and NMOS types, combined with current-limiting resistors and diode protection, enhancing the reliability of the switching process and preventing insufficient conduction or overvoltage. Furthermore, the low-voltage power supply, connected across the output terminal via a diode, ensures stable power supply to the operational amplifier within the intermediate amplitude range, guaranteeing power supply accuracy and system stability over a wide input range, while also improving the reliability and measurement performance of the precision source meter.

[0047] Figure 3 The diagram shows waveforms of the output voltage and input voltage of an unbalanced power supply circuit according to one embodiment of this application. Figure 3 As shown, the yellow channel represents the positive output of the unbalanced power supply circuit, the red channel represents the negative output of the unbalanced power supply circuit, and the blue channel represents the input voltage VIN of the unbalanced power supply circuit. The four supply voltages shown in the figure are +48V, +5V, -48V, and -5V, respectively. The input voltage is pulsed from -30V to +30V to demonstrate how the output power supply switches with the input voltage.

[0048] Figure 4 A structural block diagram of a precision source table according to an embodiment of this application is shown. Figure 4 As shown, the precision source meter includes a power supply circuit, a signal conditioning circuit, and an output circuit connected in sequence. The power supply circuit provides operating power to each circuit of the precision source meter. The signal conditioning circuit generates and regulates voltage or current signals. The signal conditioning circuit includes an operational amplifier and an unbalanced power supply circuit as described above. The positive output terminal of the unbalanced power supply circuit is connected to the positive power supply terminal of the operational amplifier, and the negative output terminal of the unbalanced power supply circuit is connected to the negative power supply terminal of the operational amplifier, used to switch the operating voltage of the operational amplifier according to the input voltage. The output circuit is connected to the device under test (DUT) and outputs the regulated voltage or current signal to the DUT.

[0049] According to this embodiment, the operational amplifier in the signal conditioning circuit obtains high-voltage or low-voltage power through an unbalanced power supply circuit, and automatically switches the power supply path according to the amplitude of the input voltage. This design enables the operational amplifier to maintain normal operation in both high-voltage and low-voltage regions, while a stable voltage is provided by a low-voltage power supply in the intermediate amplitude range, thereby ensuring the continuity and reliability of signal transmission and amplitude adjustment between the signal conditioning circuit and the output measurement circuit.

[0050] In one embodiment, reference Figure 4 The signal conditioning circuit also includes an FPGA module and a power drive module. The FPGA module is connected to the power supply circuit to receive external voltage and current commands and output control signals. The power drive module's input is connected to the FPGA module, and its output is connected to the output circuit; it generates voltage or current signals based on the control signals. The operational amplifier's input is connected to the power drive module, and its output is connected to the FPGA module; it acquires the voltage or current signals output by the power drive module in real time and feeds them back to the FPGA module to achieve closed-loop control of the voltage or current signals.

[0051] According to the above embodiment, the FPGA module receives the set voltage or current command, converts it into a control signal, and sends it to the power drive module. The power drive module amplifies the control signal output by the FPGA according to a certain ratio and generates a corresponding voltage or current signal, which is applied to the device under test (DUT) through the output circuit. Simultaneously, the operational amplifier acquires the output of the power drive module and feeds the acquired voltage or current signal back to the FPGA module. The FPGA module adjusts based on the deviation between the feedback signal and the set command, continuously correcting the output to ensure that the voltage or current at the DUT remains stable at the preset value, thus realizing the closed-loop control process of the precision source meter. Through the above process, the voltage or current output by the source meter can accurately follow the set command, and the feedback adjustment mechanism can maintain stable and high-precision output even under load changes or environmental interference.

[0052] 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.

[0053] 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. An unbalanced power supply circuit, characterized by, It includes a positive power switching module, a negative power switching module, a low-voltage positive power supply, a high-voltage positive power supply, a low-voltage negative power supply, and a high-voltage negative power supply; Both the positive power switching module and the negative power switching module are connected to the input voltage VIN. The positive power switching module is connected to the high-voltage positive power supply, and the negative power switching module is connected to the high-voltage negative power supply. The positive output terminal of the unbalanced power supply circuit is connected to the low-voltage positive power supply and the positive power switching module, respectively, and the negative output terminal of the unbalanced power supply circuit is connected to the low-voltage negative power supply and the negative power switching module, respectively. When the input voltage VIN is higher than the positive voltage threshold, the positive power supply switching module is turned on and the negative power supply switching module is turned off, so that the positive output voltage of the unbalanced power supply circuit is provided by the high voltage positive power supply and the negative output voltage of the unbalanced power supply circuit is provided by the low voltage negative power supply. When the input voltage VIN is lower than the negative voltage threshold, the negative power supply switching module is turned on and the positive power supply switching module is turned off, so that the negative output voltage of the unbalanced power supply circuit is provided by the high voltage negative power supply and the positive output voltage of the unbalanced power supply circuit is provided by the low voltage positive power supply. When the input voltage VIN is between the positive voltage threshold and the negative voltage threshold, both the positive power supply switching module and the negative power supply switching module are disconnected, so that the voltage at the positive output terminal of the unbalanced power supply circuit is provided by the low-voltage positive power supply, and the voltage at the negative output terminal is provided by the low-voltage negative power supply.

2. The unbalanced power supply circuit according to claim 1, characterized by, The unbalanced power supply circuit also includes a first diode D1 and a second diode D2; The anode of the first diode D1 is connected to the low-voltage positive power supply, and the cathode of the first diode D1 is connected to the positive output terminal of the unbalanced power supply circuit. The cathode of the second diode D2 is connected to the low-voltage negative power supply, and the anode of the second diode D2 is connected to the negative output terminal of the unbalanced power supply circuit.

3. The unbalanced power supply circuit according to claim 1, characterized in that, The positive power supply switching module includes a first voltage detection unit and a first switching unit connected to each other. The first switching unit is connected to the positive output terminal of the high voltage positive power supply and the unbalanced power supply circuit, respectively. The first voltage detection unit is configured to turn on the first switching unit when it detects that the input voltage VIN is higher than a positive voltage threshold.

4. The unbalanced power supply circuit according to claim 1, characterized by, The negative power supply switching module includes a second voltage detection unit and a second switching unit that are interconnected. The second switching unit is connected to the negative output terminal of the high voltage negative power supply and the unbalanced power supply circuit, respectively. The second voltage detection unit is configured to turn on the second switching unit when it detects that the input voltage VIN is lower than the negative voltage threshold.

5. The unbalanced power supply circuit according to claim 3, characterized in that, The first voltage detection unit includes a first transistor Q1 and a third diode D3; The base of the first transistor Q1 is connected to the input voltage VIN, the emitter of the first transistor Q1 is grounded, and the collector of the first transistor Q1 is connected to the first switching unit. The anode of the third diode D3 is connected to the emitter of the first transistor Q1, and the cathode of the third diode D3 is connected to the base of the first transistor Q1.

6. The unbalanced power supply circuit according to claim 5, wherein The first switching unit includes a first switching transistor M1 and a first resistor R1; The gate of the first switching transistor M1 is connected to the collector of the first transistor Q1, the source of the first switching transistor M1 is connected to the high voltage positive power supply, and the drain of the first switching transistor M1 is connected to the positive output terminal of the unbalanced power supply circuit. The first end of the first resistor R1 is connected to the gate of the first switch M1, and the second end of the first resistor R1 is connected to the source of the first switch M1.

7. The unbalanced power supply circuit according to claim 6, characterized by The first transistor Q1 is an NPN transistor, and the first switch M1 is a PMOS transistor.

8. The unbalanced power supply circuit according to claim 4, wherein The second voltage detection unit includes a second transistor Q2 and a fourth diode D4; The base of the second transistor Q2 is connected to the input voltage VIN, the emitter of the second transistor Q2 is grounded, and the collector of the second transistor Q2 is connected to the second switching unit. The anode of the fourth diode D4 is connected to the emitter of the second transistor Q2, and the cathode of the fourth diode D4 is connected to the base of the second transistor Q2.

9. The unbalanced power supply circuit according to claim 8, characterized by The second switching unit includes a second switching transistor M2 and a second resistor R2; The gate of the second switching transistor M2 is connected to the collector of the second transistor Q2, the source of the second switching transistor M2 is connected to the high voltage negative power supply, and the drain of the second switching transistor M2 is connected to the negative output terminal of the unbalanced power supply circuit. The first end of the second resistor R2 is connected to the gate of the second switch M2, and the second end of the second resistor R2 is connected to the source of the second switch M2.

10. The unbalanced power supply circuit according to claim 9, wherein The second transistor Q2 is a PNP transistor, and the second switch M2 is an NMOS transistor.

11. A precision source meter, characterized in that, It includes a power supply circuit, a signal conditioning circuit, and an output circuit connected in sequence; The power supply circuit is used to provide operating power to each circuit of the precision source meter; The signal conditioning circuit is used to generate and regulate voltage or current signals. The signal conditioning circuit includes an operational amplifier and an unbalanced power supply circuit as described in any one of claims 1-9. The positive output terminal of the unbalanced power supply circuit is connected to the positive power supply terminal of the operational amplifier, and the negative output terminal of the unbalanced power supply circuit is connected to the negative power supply terminal of the operational amplifier. The circuit is used to switch the operating voltage of the operational amplifier according to the input voltage. The output circuit is connected to the device under test and is used to output the regulated voltage or current signal to the device under test.

12. The precision source meter of claim 11, wherein, The signal conditioning circuit also includes an FPGA module and a power drive module; The FPGA module is connected to the power supply circuit and is used to receive external voltage and current commands and output control signals. The input terminal of the power drive module is connected to the FPGA module, and the output terminal is connected to the output circuit, used to generate voltage or current signals according to the control signal; The input terminal of the operational amplifier is connected to the power drive module, and the output terminal is connected to the FPGA module. It is used to acquire the voltage or current signal output by the power drive module in real time and feed it back to the FPGA module to realize closed-loop control of the voltage or current signal.

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