An adaptive unbalanced power supply circuit and precision source meter

Abstract

This application discloses an adaptive unbalanced power supply circuit and a precision source meter. The unbalanced power supply circuit includes an input voltage regulation module, a voltage bias module, and an output drive module connected in sequence. The input voltage regulation module is connected to the input voltage VIN. The input voltage regulation module is configured to output a clamping voltage corresponding to the input voltage when the input voltage VIN is lower than a first threshold voltage or higher than a second threshold voltage; and to output a follower voltage that is substantially the same as the input voltage VIN when the input voltage VIN is between the first threshold voltage and the second threshold voltage. The voltage bias module is configured to introduce a preset voltage bias based on the clamping voltage or the follower voltage, and output a bias voltage with a fixed voltage difference compared to the clamping voltage or the follower voltage. The output drive module has a positive output terminal and a negative output terminal, and is configured to provide positive and negative power supplies to the sampling operational amplifier based on the bias voltage.

Description

Technical Field

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

[0002] In precision source meters, the sampling operational amplifier circuit typically requires extremely low offset voltage and noise to ensure measurement accuracy; therefore, low-voltage operational amplifiers are often preferred in design. However, when the source meter has a large voltage output capability, if the operational amplifier's power rail remains fixed, it must meet the voltage withstand capability across the entire output range. This makes it difficult to apply low-voltage operational amplifiers and limits further improvements in system performance. To balance high-voltage output and low-noise measurement, existing technologies often employ floating power supplies, allowing the operational amplifier's power supply reference point to change synchronously with the output voltage, thus ensuring the availability of low-voltage operational amplifiers. However, floating power supplies usually require isolation power modules and transformers, resulting in complex circuitry, larger size, and space consumption, which is detrimental to the miniaturization and multi-channel integration of the source meter. Therefore, how to enable the operational amplifier's power rail to dynamically adjust with the input voltage without relying on complex isolation power supplies has become a key issue in the design of precision source meters. Utility Model Content

[0003] The purpose of this application is to provide an adaptive unbalanced power supply circuit and a precision source meter to solve the problems in the prior art where low-voltage operational amplifiers are difficult to apply under high-voltage output conditions, and floating power supply schemes lead to high circuit complexity and limited integration.

[0004] To achieve the above objectives, this application discloses the following technical solution: The first aspect of this application provides an adaptive unbalanced power supply circuit, comprising an input voltage regulation module, a voltage bias module, and an output drive module connected in sequence, wherein the input voltage regulation module is connected to the input voltage VIN; The input voltage regulation module is configured to output a clamping voltage corresponding to the input voltage when the input voltage VIN is lower than a first threshold voltage or higher than a second threshold voltage; and to output a follower voltage that is substantially the same as the input voltage VIN when the input voltage VIN is between the first threshold voltage and the second threshold voltage. The voltage bias module is configured to introduce a preset voltage bias based on the clamping voltage or the following voltage, and output a bias voltage with a fixed voltage difference compared with the clamping voltage or the following voltage. The output driving module has a positive output terminal and a negative output terminal, and is configured to provide positive and negative voltages to the sampling operational amplifier based on the bias voltage.

[0005] Optionally, the input voltage regulation module includes a first voltage regulation unit, the first voltage regulation unit comprising: The first resistor R1 has its first terminal connected to the input voltage VIN; The first diode D1 has its negative terminal connected to the second end of the first resistor R1, and its positive terminal grounded. The first operational amplifier U1 has its non-inverting input connected to the negative terminal of the first diode D1, its inverting input connected to the output terminal of the first operational amplifier U1, its positive power supply connected to a high-voltage positive power supply, its negative power supply connected to a low-voltage negative power supply, and its output connected to a voltage bias module.

[0006] Optionally, the voltage biasing module includes a first voltage biasing unit, the first voltage biasing unit comprising: The positive terminal of the first Zener diode D2 is connected to the output terminal of the first operational amplifier U1; The second resistor R2 has its first end connected to a high-voltage positive power supply and its second end connected to the negative terminal of the first Zener diode D2. The second operational amplifier U2 has its positive power supply terminal connected to a high-voltage positive power supply, its negative power supply terminal connected to a low-voltage negative power supply, and its non-inverting input terminal connected to the negative terminal of the first Zener diode D2. The third resistor R3 has its first end connected to the output terminal of the second operational amplifier U2, and its second end connected to the inverting input terminal of the second operational amplifier U2. The second end of the third resistor R3 is also connected to the output drive module.

[0007] Optionally, the output driving module includes a first output driving unit, the first output driving unit comprising: The first transistor Q1 has its base connected to the second end of the third resistor R3, its collector connected to the high-voltage positive power supply, and its emitter serving as the positive output terminal.

[0008] Optionally, the input voltage regulation module further includes a second voltage regulation unit, the second voltage regulation unit comprising: The fourth resistor R4 has its first terminal connected to the input voltage VIN; The positive terminal of the third diode D3 is connected to the second terminal of the fourth resistor R4, and the negative terminal is grounded. The third operational amplifier U3 has its non-inverting input connected to the positive terminal of the third diode D3, its inverting input connected to the output terminal of the third operational amplifier U3, its positive power supply connected to a low-voltage positive power supply, its negative power supply connected to a high-voltage negative power supply, and its output connected to a voltage bias module.

[0009] Optionally, the voltage biasing module further includes a second voltage biasing unit, the second voltage biasing unit comprising: The negative terminal of the second Zener diode D4 is connected to the output terminal of the third operational amplifier U3. The fifth resistor R5 has its first end connected to a high-voltage negative power supply and its second end connected to the positive terminal of the second Zener diode D4. The fourth operational amplifier U4 has its positive power supply terminal connected to a low-voltage positive power supply, its negative power supply terminal connected to a high-voltage negative power supply, and its non-inverting input terminal connected to the positive terminal of the second Zener diode D4. The sixth resistor R6 has its first end connected to the output terminal of the fourth operational amplifier U4, and its second end connected to the inverting input terminal of the fourth operational amplifier U4. The second end of the sixth resistor R6 is also connected to the output drive module.

[0010] Optionally, the output driving module includes a second output driving unit, the second output driving unit comprising: The base of the second transistor Q2 is connected to the second end of the sixth resistor R6, the collector is connected to the high-voltage negative power supply, and the emitter serves as the negative output terminal.

[0011] A second aspect of this utility model provides a precision source meter, 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 adjust the voltage or current signal. The signal conditioning circuit includes a sampling 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 sampling operational amplifier, and the negative output terminal of the unbalanced power supply circuit is connected to the negative power supply terminal of the sampling operational amplifier. It is used to adjust the operating voltage of the sampling 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.

[0012] 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 sampling operational amplifier is connected to the power drive module, and the output terminal is connected to the FPGA module. It is used to collect 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.

[0013] The adaptive unbalanced power supply circuit provided in this application can adaptively output clamping voltage or follower voltage according to different input voltage states, thereby achieving protection under excessively high or low input voltage conditions and maintaining stable voltage transmission within the normal range. Based on this, a fixed voltage difference is introduced through a voltage bias module to form an asymmetrical power rail structure, enabling the sampling operational amplifier to receive stable positive and negative voltages under different power input conditions. Finally, a reliable bipolar power supply is achieved through an output drive module, which not only expands the operating range of the operational amplifier but also reduces the power consumption and complexity of traditional symmetrical power supply methods, thus balancing the circuit's measurement accuracy, stability, and system adaptability.

[0014] Furthermore, the input voltage regulation unit clamps or follows the input voltage, ensuring protection against overvoltage or undervoltage while maintaining accurate voltage transmission within the normal range. A voltage bias unit, combined with a Zener diode and operational amplifier configuration, introduces a fixed bias on top of the clamping or following voltage, ensuring a stable voltage difference at the output and thus creating an asymmetrical power rail. Additionally, the output drive unit utilizes transistors to amplify the current drive capability of the operational amplifier's power supply, efficiently converting the bias voltage into positive and negative bipolar outputs to guarantee a stable power supply to the sampling operational amplifier. Attached Figure Description

[0015] 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.

[0016] Figure 1 An unbalanced power supply circuit is shown in the preliminary design of the utility model. Figure 2 A waveform diagram of the output voltage of a preliminary unbalanced circuit according to an embodiment of this application is shown; Figure 3 A structural block diagram of an adaptively adjusted unbalanced power supply circuit according to an embodiment of this application is shown; Figure 4 An adaptive adjustment unbalanced power supply circuit topology diagram according to one embodiment of this application is shown; Figure 5 The diagram shows the waveforms of the input and output voltages of an unbalanced power supply circuit according to an embodiment of this application. Figure 6 The pulse scan waveform of the output voltage of the unbalanced power supply circuit is shown when the input voltage VIN is 0V. Figure 7 The diagram shows the pulse sweep waveform of the output voltage of the unbalanced power supply circuit when the input voltage changes from -40V to +40V. Figure 8The diagram shows the pulse sweep waveform of the output voltage of the unbalanced power supply circuit when the input voltage drops from +40V to -40V. Figure 9 The diagram shows the pulse scan waveform of the output voltage of the unbalanced power supply circuit when the input voltage VIN drops from +40V to 0V. Figure 10 The diagram shows the pulse sweep waveform of the output voltage of an unbalanced power supply circuit when the input voltage VIN rises from -40V to 0V. Figure 11 A structural block diagram of a precision source table according to an embodiment of this application is shown. Detailed Implementation

[0017] 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.

[0018] 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.

[0019] 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.

[0020] In existing technologies, precision operational amplifier circuits typically employ a fixed voltage supply method with symmetrical power rails or a single power rail. This approach is mature in design, simple to implement, and highly reliable. Its fixed circuit topology facilitates engineering implementation, and its long-term application has demonstrated good versatility and stability, leading to its widespread adoption by those skilled in the art. However, due to the fixed power rail, when the operational amplifier needs to cover a large input common-mode voltage range, a high-voltage operational amplifier must be selected. High-voltage operational amplifiers generally have inferior offset voltage and noise performance compared to low-voltage operational amplifiers, resulting in decreased sampling accuracy. Conversely, using a low-voltage operational amplifier to achieve better noise and offset voltage performance limits the usable input common-mode range, failing to meet the requirements for wide-range voltage measurement. Furthermore, the fixed power supply method cannot dynamically adjust the supply voltage based on the input voltage, restricting the system's flexibility in balancing high accuracy and wide voltage range. Because the fixed voltage schemes with symmetrical power rails and a single power rail are widely used in textbooks, reference designs, and engineering practices, a technical bias has gradually formed in the industry, with the general consensus that operational amplifier circuits should always be powered by symmetrical power rails or a fixed single power rail. Therefore, many designers tend to follow traditional design ideas, which limits the further optimization of power supply circuit performance and makes it difficult for innovative power supply solutions to be widely adopted.

[0021] After breaking through existing technological biases, the utility model inventor first proposed a preliminary unbalanced power supply circuit. Figure 1 An unbalanced power supply circuit of a preliminary design for a utility model is shown, such as... Figure 1 As shown, the preliminary unbalanced power supply circuit includes a positive voltage output module and a negative voltage output module, both connected to the input voltage. The positive voltage output module is connected to both the high-voltage positive power supply and the low-voltage negative power supply, and the negative voltage output module is connected to both the high-voltage negative power supply and the low-voltage negative power supply. The preliminary unbalanced power supply circuit operates under the following three conditions: 1) When the input voltage is positive high voltage, the positive voltage output module is turned on and starts working to output a positive voltage through the high voltage positive power supply. At this time, the negative voltage output module is turned off, and a negative voltage is output through the low voltage negative power supply.

[0022] 2) When the input voltage amplitude is very low, both the positive voltage output module and the low voltage output module are disconnected, and the positive voltage is output through the low voltage positive power supply and the negative voltage is output through the low voltage negative power supply.

[0023] 3) When the input voltage is negative high voltage, the low voltage output module turns on and starts working to output a negative voltage through the high voltage negative power supply. At this time, the high voltage output module turns off and outputs a positive voltage through the low voltage positive power supply.

[0024] The aforementioned preliminary unbalanced power supply circuit achieves dynamic distribution of positive and negative voltages by selectively activating the positive or negative voltage output module within different input voltage ranges. This provides stable positive and negative output voltages under high-voltage inputs while maintaining the lowest possible output voltage under low-voltage inputs, thus solving the problem in existing single-rail or symmetrical power supply methods that cannot simultaneously handle positive and negative outputs under high and low voltage conditions. However, this preliminary unbalanced power supply circuit is prone to transient overvoltages or brief parallel connections between the two power supplies during input voltage switching, which may interfere with or damage the downstream sampling operational amplifier. Figure 2 A waveform diagram of the output voltage of a preliminary unbalanced circuit according to an embodiment of this application is shown, as follows: Figure 2 As shown, in the experiment, the operational amplifier used was ADA4522. When the input voltage switched from +1V to -1V, the power supply switching sequentially went through conditions 1, 2, and 3. However, due to the discharge effect of parasitic capacitance, Figure 1 The turn-off delay of each MOSFET results in a very narrow voltage sustaining range in operating condition 2, only about ±0.5V in the experimental circuit. The time for the output voltage to drop from +0.5V to -0.5V is shorter than the turn-off time required for the PMOS transistor. Therefore, when the output switches to below -0.5V, the NMOS transistor has already started conducting to output a negative voltage (dropping from -5V to -48V), while the PMOS transistor is still turning off to output a positive voltage (dropping from +48V to +5V). At this time, the positive and negative voltage difference of the power supply may exceed +55V, which is outside the power rail range of the ADA4522, leading to abnormal output and even damage to the op-amp.

[0025] Taking the M9614A as an example, its maximum input voltage is ±30V. Figure 1 The four power rails shown in the initial unbalanced power supply diagram are ±36V and ±15V. In this case, the voltage range for operating condition 2 can be controlled within ±15V, and the two MOSFETs have sufficient time to turn off and then on during output switching, avoiding simultaneous conduction. However, when the input voltage increases to +40V, to ensure the total difference between the high and low voltage rails is less than 55V to accommodate the low-noise ADA4522 op-amp, the range of the low-voltage power supply must be compressed. This increases the risk of both MOSFETs turning on simultaneously, thus creating a fundamental contradiction.

[0026] Therefore, although the inventors broke through traditional technical biases in the initial research and development process, the initial unbalanced power supply circuit still presented technical challenges related to transient overvoltage during switching. Through continuous optimization and improvement, the adaptive unbalanced power supply circuit proposed in this application was finally introduced. This circuit breaks through the limitations of traditional designs, achieves adaptive adjustment of input voltage, and rationally allocates positive and negative power rails, ensuring safe and stable power supply to the operational amplifier circuit, thereby improving the reliability and performance of the circuit.

[0027] Figure 3 A structural block diagram of an adaptively adjusted unbalanced power supply circuit according to one embodiment of this application is shown. Figure 3 As shown, the adaptive unbalanced power supply circuit includes an input voltage regulation module 10, a voltage bias module 20, and an output drive module 30 connected in sequence. The input voltage regulation module 10 is connected to the input voltage VIN. The input voltage regulation module 10 is configured to output a clamping voltage corresponding to the input voltage when the input voltage VIN is lower than a first threshold voltage or higher than a second threshold voltage; and to output a follower voltage that is substantially the same as the input voltage VIN when the input voltage VIN is between the first and second threshold voltages. The voltage bias module 20 is configured to introduce a preset voltage bias based on the clamping voltage or follower voltage, and output a bias voltage with a fixed voltage difference compared to the clamping voltage or follower voltage. The output drive module 30 has a positive output terminal and a negative output terminal, configured to provide positive and negative voltages to the sampling operational amplifier based on the bias voltage.

[0028] According to the above embodiments, the technical solution of this application can adaptively output clamping voltage or following voltage according to different input voltage states, thereby achieving protection under excessively high or low input voltage conditions and maintaining stable voltage transmission within the normal range. Based on this, a fixed voltage difference is introduced through the voltage bias module 20 to form an asymmetrical power rail structure, enabling stable positive and negative voltages to be provided to the sampling operational amplifier under different power input conditions. Finally, reliable bipolar power supply is achieved through the output drive module 30, which not only expands the operating range of the operational amplifier but also reduces the power consumption and complexity of traditional symmetrical power supply methods, thus balancing the circuit's measurement accuracy, stability, and system adaptability.

[0029] Figure 4 An adaptive adjustment unbalanced power supply circuit topology diagram according to one embodiment of this application is shown. Figure 4 As shown, the input voltage regulation module 10 includes a first voltage regulation unit 11, which includes a first resistor R1, a first diode D1, and a first operational amplifier U1. The first terminal of the first resistor R1 is connected to the input voltage VIN. The cathode of the first diode D1 is connected to the second terminal of the first resistor R1, and the anode is grounded. The non-inverting input terminal of the first operational amplifier U1 is connected to the cathode of the first diode D1, the inverting input terminal is connected to the output terminal of the first operational amplifier U1, the positive power supply terminal is connected to a high-voltage positive power supply, the negative power supply terminal is connected to a low-voltage negative power supply, and the output terminal is connected to the voltage bias module 20.

[0030] In this embodiment, when the input voltage VIN is lower than the first threshold voltage, i.e., the input voltage VIN is a negative high voltage, the first diode D1 operates as a clamping negative voltage diode, limiting the input voltage to near its conduction voltage. At this time, the first voltage regulation unit 11 outputs a stable negative clamping voltage. When the input voltage VIN is higher than the second threshold voltage, i.e., the input voltage VIN is a positive high voltage, the first diode D1 acts as a clamping negative voltage diode, and does not conduct because the input voltage is lower than its forward conduction voltage. At this time, the first voltage regulation unit 11 does not impose additional restrictions on the input voltage VIN, and its output voltage is basically consistent with the input voltage VIN. When the input voltage VIN is between the first threshold voltage and the second threshold voltage, i.e., the amplitude of the input voltage VIN is low, the first diode D1 remains in the off state. At this time, the first voltage regulation unit 11 outputs a following voltage that is basically the same as the input voltage VIN. This embodiment automatically adjusts the clamping and following states of the input voltage, enabling the first voltage regulation unit 11 to provide a continuous and stable output voltage over a wide input voltage range, thereby ensuring the reliable operation of the downstream sampling operational amplifier.

[0031] In one embodiment, reference Figure 4 The voltage bias module 20 includes a first voltage bias unit 21, which includes a first Zener diode D2, a second resistor R2, a second operational amplifier U2, and a third resistor R3. The positive terminal of the first Zener diode D2 is connected to the output terminal of the first operational amplifier U2. The first end of the second resistor R2 is connected to a high-voltage positive power supply, and the second end is connected to the negative terminal of the first Zener diode D2. The positive power supply terminal of the second operational amplifier U2 is connected to a high-voltage positive power supply, the negative power supply terminal is connected to a low-voltage negative power supply, and the non-inverting input terminal is connected to the negative terminal of the first Zener diode D2. The first end of the third resistor R3 is connected to the output terminal of the second operational amplifier U2, the second end is connected to the inverting input terminal of the second operational amplifier U2, and the second end of the third resistor R3 is also connected to the output drive module 30.

[0032] In this embodiment, the first voltage bias unit 21 uses a first Zener diode D2 and a second operational amplifier U2 to regulate the output voltage from the first voltage regulation unit 11. Specifically, the first Zener diode D2 provides a reference voltage for the clamping voltage or follower voltage output by the first voltage regulation unit 11, ensuring that the voltage at the non-inverting input of the second operational amplifier U2 has a fixed voltage difference compared to the clamping voltage or follower voltage output by the first voltage regulation unit 11. This difference is then addressed by the negative feedback regulation of the second operational amplifier U2 and the third resistor R3, resulting in a stable bias voltage output. Through this design, the first voltage bias unit 21 can output a stable bias voltage when the input voltage changes, ensuring that the output drive module 30 obtains reliable positive and negative voltages. This guarantees that the subsequent sampling operational amplifier can operate normally under different input conditions, avoiding the impact of voltage fluctuations on sampling accuracy.

[0033] In one embodiment, reference Figure 4 The output drive module 30 includes a first output drive unit 31, which includes a first transistor Q1. The base of the first transistor Q1 is connected to the second end of the third resistor R3, the collector is connected to a high-voltage positive power supply, and the emitter serves as the positive output terminal.

[0034] In the above embodiment, the first output driving unit 31 converts the bias voltage from the first voltage biasing unit 21 into a positive voltage that can be used by the sampling operational amplifier through the first transistor Q1. Specifically, the base of the first transistor Q1 receives the control signal provided by the third resistor R3, and through the connection of the collector to the high-voltage positive power supply and the output of the emitter, the first transistor Q1 realizes the voltage amplification and driving functions, so that the output voltage can be stably provided to the subsequent circuit.

[0035] In one embodiment, reference Figure 4 The input voltage regulation module 10 also includes a second voltage regulation unit 12, which includes a fourth resistor R4, a third diode D3, and a third operational amplifier U3. The first terminal of the fourth resistor R4 is connected to the input voltage VIN. The anode of the third diode D3 is connected to the second terminal of the fourth resistor R4, and the cathode is grounded. The non-inverting input terminal of the third operational amplifier U3 is connected to the anode of the third diode D3, and the inverting input terminal is connected to the output terminal of the third operational amplifier U3. The positive power supply terminal is connected to a low-voltage positive power supply, the negative power supply terminal is connected to a high-voltage negative power supply, and the output terminal is connected to the voltage bias module 20.

[0036] In this embodiment, when the input voltage VIN is lower than the first threshold voltage, i.e., the input voltage VIN is a negative high voltage, the second diode D2 acts as a positive clamping voltage diode. Since the input voltage is lower than its forward conduction voltage, it does not conduct. At this time, the second voltage regulation unit 12 does not impose any additional restrictions on the input voltage VIN, and its output voltage is essentially consistent with the input voltage. When the input voltage VIN is higher than the second threshold voltage, i.e., the input voltage VIN is a positive high voltage, the second diode D2 operates as a positive clamping voltage diode, limiting the input voltage VIN to near its conduction voltage. At this time, the second voltage regulation unit 12 outputs a stable positive clamping voltage. When the input voltage VIN is between the first and second threshold voltages, i.e., the amplitude of the input voltage VIN is low, the second diode D2 remains in the off state. At this time, the second voltage regulation unit 12 outputs a following voltage that is essentially the same as the input voltage VIN.

[0037] In one embodiment, reference Figure 4The voltage bias module 20 also includes a second voltage bias unit 22, which includes a second Zener diode D4, a fifth resistor R5, a fourth operational amplifier U4, and a sixth resistor R6. The negative terminal of the second Zener diode D4 is connected to the output terminal of the third operational amplifier U3. The first terminal of the fifth resistor R5 is connected to a high-voltage negative power supply, and the second terminal is connected to the positive terminal of the second Zener diode D4. The positive power supply terminal of the fourth operational amplifier U4 is connected to a low-voltage positive power supply, the negative power supply terminal is connected to a high-voltage negative power supply, and the non-inverting input terminal is connected to the positive terminal of the second Zener diode D4. The first terminal of the sixth resistor R6 is connected to the output terminal of the fourth operational amplifier U4, and the second terminal is connected to the inverting input terminal of the fourth operational amplifier U4. The second terminal of the sixth resistor R6 is also connected to the output drive module 30.

[0038] In this embodiment, the second voltage biasing unit 22 uses the second Zener diode D4 and the fourth operational amplifier U4 to regulate the output voltage from the second voltage regulation unit 12. Specifically, the second Zener diode D4 provides a reference voltage for the clamping voltage or follower voltage output by the second voltage regulation unit 12, so that the voltage at the non-inverting input of the fourth operational amplifier U4 has a fixed voltage difference compared with the clamping voltage or follower voltage output by the second voltage regulation unit 12. This results in a stable bias voltage output through the negative feedback regulation of the fourth operational amplifier U4 and the sixth resistor R6.

[0039] In one embodiment, reference Figure 4 The output drive module 30 includes a second output drive unit 32, which includes a second transistor Q2. The base of the second transistor Q2 is connected to the second terminal of the sixth resistor R6, the collector is connected to a high-voltage negative power supply, and the emitter serves as the negative output terminal.

[0040] In the above embodiment, the second output driving unit 32 converts the bias voltage from the second voltage biasing unit 22 into a negative voltage that can be used by the sampling operational amplifier through the second transistor Q2. Specifically, the base of the second transistor Q2 receives the control signal provided by the sixth resistor R6, and through the connection of the collector to the high-voltage negative power supply and the output of the emitter, the second transistor Q2 realizes the voltage amplification and driving functions, so that the output voltage can be stably provided to the subsequent circuit.

[0041] According to the above embodiments, this application achieves clamping or following of the input voltage through an input voltage regulation unit, ensuring protection when the voltage is too high or too low, while maintaining the accuracy of voltage transmission within the normal range. By combining a voltage bias unit with a Zener diode and operational amplifier configuration, a fixed bias is introduced based on the clamping or following voltage, ensuring a stable voltage difference at the output, thus forming an asymmetrical power rail. Furthermore, the output drive unit utilizes transistors to amplify the current drive capability of the operational amplifier power supply, efficiently converting the bias voltage into positive and negative bipolar outputs, ensuring a stable power supply to the sampling operational amplifier.

[0042] To facilitate understanding of the technical solution of this application, the following description is provided in conjunction with specific embodiments.

[0043] If the input voltage is set to +40V, the regulated voltage of both the first Zener diode D1 and the second Zener diode D2 is 5.6V. At this time, the output voltage of the first voltage adjustment unit 11 is 39.999054V, and the output voltage of the first voltage bias unit 21 is 45.564468V. Therefore, the final positive voltage output by the unbalanced power supply circuit is 44.772526V. Meanwhile, the output voltage of the second voltage adjustment unit 12, under the action of the third diode D3, is 472.82594mV, or 0.47282594V. Therefore, the output voltage of the second voltage bias unit 22 is -5.1180549V, and the final negative voltage output by the unbalanced power supply circuit is -4.4527683V. Thus, the unbalanced power supply circuit of this application ultimately provides approximately +44.77V and -4.45V positive and negative power supply voltages to the sampling operational amplifier, achieving stable power supply under a wide input range.

[0044] If the input voltage is set to -40V, the regulated voltage of both the first Zener diode D1 and the second Zener diode D2 is 5.6V. At this time, under the action of the first diode D1, the output voltage of the first voltage adjustment unit 11 is -472.82594mV, or -0.47282594V. Therefore, the output voltage of the first voltage bias unit 21 is 5.1180549V, and the final positive voltage output by the unbalanced power supply circuit is 4.4527683V. Meanwhile, the output voltage of the second voltage adjustment unit 12 is -39.999054V, and the output voltage of the second voltage bias unit 22 is -45.564468V. Therefore, the final negative voltage output by the unbalanced power supply circuit is -44.772526V. Thus, the unbalanced power supply circuit of this application ultimately provides approximately +4.45V and -44.77V positive and negative power supply voltages to the sampling operational amplifier, achieving stable power supply over a wide input range.

[0045] Figure 5 The diagram shows waveforms of the input and output voltages of an unbalanced power supply circuit according to an embodiment of this application. Figure 5As shown, the green curve represents the input voltage VIN, the blue curve represents the positive output voltage, and the red curve represents the negative output voltage. Circuit simulation shows that the positive and negative output voltages of this application dynamically adjust with changes in the input voltage VIN. At least one power rail can adaptively adjust to follow the input voltage, rather than switching fixedly, thereby achieving a continuous and stable output response.

[0046] Figure 6 The diagram shows the pulse sweep waveform of the output voltage of the unbalanced power supply circuit when the input voltage VIN is 0V. Figure 6 As shown, the blue curve represents the input voltage VIN, the yellow curve represents the positive output voltage, and the red curve represents the negative output voltage. When the input voltage VIN is 0V, the unbalanced power supply circuit of this application provides low-voltage positive and negative power supplies to the operational amplifier, thereby effectively reducing the static power consumption of the operational amplifier.

[0047] Figure 7 The diagram shows the pulse sweep waveform of the output voltage of the unbalanced power supply circuit when the input voltage changes from -40V to +40V. Figure 7 As shown, the blue curve represents the input voltage VIN, the yellow curve represents the positive output voltage, and the red curve represents the negative output voltage. In this case, the positive and negative output voltages of the unbalanced power supply in this application are dynamically adjusted to follow the input voltage VIN, achieving continuous following rather than fixed switching.

[0048] Figure 8 The diagram shows the pulse sweep waveform of the output voltage of an unbalanced power supply circuit when the input voltage drops from +40V to -40V. Figure 8 As shown, the blue curve represents the input voltage VIN, the yellow curve represents the positive output voltage, and the red curve represents the negative output voltage. In this case, the positive and negative output voltages of the unbalanced power supply in this application are always kept outside the input voltage range and are dynamically adjusted accordingly.

[0049] Figure 9 The diagram shows a pulse sweep waveform of the output voltage of an unbalanced power supply circuit when the input voltage VIN drops from +40V to 0V. Figure 9 As shown, the blue curve represents the input voltage VIN, the yellow curve represents the positive output voltage, and the red curve represents the negative output voltage. In this case, the positive power supply voltage of the unbalanced power supply in this application always rapidly follows the changes in the input voltage VIN.

[0050] Figure 10 The diagram shows the pulse sweep waveform of the output voltage of an unbalanced power supply circuit as the input voltage VIN rises from -40V to 0V. Figure 10As shown, the blue curve represents the input voltage VIN, the yellow curve represents the positive output voltage, and the red curve represents the negative output voltage. In this case, the negative power supply voltage of the unbalanced power supply in this application always rapidly follows the changes in the input voltage VIN.

[0051] According to the above embodiments, the adaptive unbalanced power supply circuit of this application can dynamically adjust the positive and negative power rails of the operational amplifier according to the input voltage of the operational amplifier, thereby reducing the limitations of the power rails on the selection of the operational amplifier. This allows the high-voltage source meter to use both a low-noise sampling operational amplifier and meet the requirements of high-voltage output. Simultaneously, this application avoids the problem of two high-voltage power supplies simultaneously conducting, which may occur in unbalanced power supply technologies based on power switching, thus improving operational reliability. Furthermore, the circuit structure of this application has high integration and small size, facilitating miniaturization design, and is particularly suitable for multi-channel source meters and high-density layout applications.

[0052] Figure 11 A structural block diagram of a precision source table according to an embodiment of this application is shown. Figure 11 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 regulates the voltage or current signal and includes a sampling operational amplifier and the unbalanced power supply circuit described in this application. The positive output terminal of the unbalanced power supply circuit is connected to the positive power supply terminal of the sampling operational amplifier, and the negative output terminal of the unbalanced power supply circuit is connected to the negative power supply terminal of the sampling operational amplifier, used to adjust the operating voltage of the sampling 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.

[0053] In one embodiment, reference Figure 11 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 sampling 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.

[0054] 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 this process, the voltage or current output by the source meter accurately follows the set command, and the feedback adjustment mechanism maintains stable and high-precision output even under load changes or environmental interference.

[0055] The unbalanced power supply circuit of this application adaptively adjusts the input voltage, providing suitable positive and negative power supplies for the sampling operational amplifier of the source meter in different voltage ranges, ensuring that the operational amplifier always operates stably under appropriate power supply conditions. This not only breaks through the voltage withstand limitation of the operational amplifier in traditional symmetrical power supply, enabling low-voltage, low-noise operational amplifiers to be used in high-voltage source meter sampling circuits, but also improves the overall system integration and power consumption performance.

[0056] 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.

[0057] 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 adaptively regulated unbalanced power supply circuit, characterized by, It includes an input voltage regulation module, a voltage bias module and an output drive module connected in sequence, wherein the input voltage regulation module is connected to the input voltage VIN; The input voltage regulation module is configured to output a clamping voltage corresponding to the input voltage when the input voltage VIN is lower than a first threshold voltage or higher than a second threshold voltage; and to output a follower voltage that is substantially the same as the input voltage VIN when the input voltage VIN is between the first threshold voltage and the second threshold voltage. The voltage bias module is configured to introduce a preset voltage bias based on the clamping voltage or the following voltage, and output a bias voltage with a fixed voltage difference compared with the clamping voltage or the following voltage. The output driving module has a positive output terminal and a negative output terminal, and is configured to provide positive and negative power supplies to the sampling operational amplifier based on the bias voltage.

2. The unbalanced power supply circuit according to claim 1, characterized by, The input voltage regulation module includes a first voltage regulation unit, the first voltage regulation unit comprising: The first resistor R1 has its first terminal connected to the input voltage VIN; The first diode D1 has its negative terminal connected to the second end of the first resistor R1, and its positive terminal grounded. The first operational amplifier U1 has its non-inverting input connected to the negative terminal of the first diode D1, its inverting input connected to the output terminal of the first operational amplifier U1, its positive power supply connected to a high-voltage positive power supply, its negative power supply connected to a low-voltage negative power supply, and its output connected to a voltage bias module.

3. The unbalanced power supply circuit according to claim 2, characterized by The voltage biasing module includes a first voltage biasing unit, which includes: The positive terminal of the first Zener diode D2 is connected to the output terminal of the first operational amplifier U1; The second resistor R2 has its first end connected to a high-voltage positive power supply and its second end connected to the negative terminal of the first Zener diode D2. The second operational amplifier U2 has its positive power supply terminal connected to a high-voltage positive power supply, its negative power supply terminal connected to a low-voltage negative power supply, and its non-inverting input terminal connected to the negative terminal of the first Zener diode D2. The third resistor R3 has its first end connected to the output terminal of the second operational amplifier U2, and its second end connected to the inverting input terminal of the second operational amplifier U2. The second end of the third resistor R3 is also connected to the output drive module.

4. The unbalanced power supply circuit according to claim 3, characterized by The output driving module includes a first output driving unit, the first output driving unit comprising: The first transistor Q1 has its base connected to the second end of the third resistor R3, its collector connected to the high-voltage positive power supply, and its emitter serving as the positive output terminal.

5. The unbalanced power supply circuit according to claim 1, wherein The input voltage regulation module further includes a second voltage regulation unit, the second voltage regulation unit comprising: The fourth resistor R4 has its first terminal connected to the input voltage VIN; The positive terminal of the third diode D3 is connected to the second terminal of the fourth resistor R4, and the negative terminal is grounded. The third operational amplifier U3 has its non-inverting input connected to the positive terminal of the third diode D3, its inverting input connected to the output terminal of the third operational amplifier U3, its positive power supply connected to a low-voltage positive power supply, its negative power supply connected to a high-voltage negative power supply, and its output connected to a voltage bias module.

6. The unbalanced power supply circuit according to claim 5, wherein The voltage biasing module further includes a second voltage biasing unit, which includes: The negative terminal of the second Zener diode D4 is connected to the output terminal of the third operational amplifier U3. The fifth resistor R5 has its first end connected to a high-voltage negative power supply and its second end connected to the positive terminal of the second Zener diode D4. The fourth operational amplifier U4 has its positive power supply terminal connected to a low-voltage positive power supply, its negative power supply terminal connected to a high-voltage negative power supply, and its non-inverting input terminal connected to the positive terminal of the second Zener diode D4. The sixth resistor R6 has its first end connected to the output terminal of the fourth operational amplifier U4, and its second end connected to the inverting input terminal of the fourth operational amplifier U4. The second end of the sixth resistor R6 is also connected to the output drive module.

7. The unbalanced power supply circuit according to claim 6, characterized in that, The output driving module includes a second output driving unit, and the second output driving unit includes: The base of the second transistor Q2 is connected to the second end of the sixth resistor R6, the collector is connected to the high-voltage negative power supply, and the emitter serves as the negative output terminal.

8. 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 adjust the voltage or current signal. The signal conditioning circuit includes a sampling operational amplifier and an unbalanced power supply circuit as described in any one of claims 1-7. The positive output terminal of the unbalanced power supply circuit is connected to the positive power supply terminal of the sampling operational amplifier, and the negative output terminal of the unbalanced power supply circuit is connected to the negative power supply terminal of the sampling operational amplifier. The circuit is used to adjust the operating voltage of the sampling 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.

9. The precision source meter according to claim 8, characterized in that, 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 sampling operational amplifier is connected to the power drive module, and the output terminal is connected to the FPGA module. It is used to collect 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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