Common-mode error calibration device of voltage and current source

Abstract

The utility model discloses a common-mode error calibration device of a voltage and current source, and the device comprises a common-mode voltage output module which comprises a calibration channel which comprises a second high end and a second low end; the second high end is used for outputting common-mode voltage, and the second low end is electrically connected with the first output low end; the first end of the current detection module is electrically connected with the first output high end and the first sensing high end, and the second end of the current detection module is electrically connected with the second high end of the calibration channel for detecting the output current of the first output high end; and the processing module is in communication connection with the voltage and current source, the current detection module and the common-mode voltage output module, and is used for configuring the output of the second high end of the common-mode voltage output module, configuring an output current expected value of the to-be-calibrated voltage and current channel, and calculating a calibration coefficient of the to-be-calibrated voltage and current channel. According to the utility model, the common-mode error of the voltage and current source can be reduced with lower cost, so that the precision of the current output by the current source is higher.

Description

Technical Field

[0001] This utility model relates to the field of testing technology, and in particular to a common-mode error calibration device for a voltage and current source. Background Technology

[0002] Voltage and current sources can provide constant voltage and / or current, and have important applications in fields such as testing technology.

[0003] However, common-mode error in voltage and current sources can worsen the accuracy of the output current when operating in constant-current mode. This reduction in current accuracy due to common-mode error is even more pronounced during high-precision testing. Furthermore, the influence of common-mode voltage not only leads to inaccurate parameter test results but also significantly reduces the pass rate of device testing.

[0004] In related technologies, devices for reducing common-mode error are limited by the resistor manufacturing process, which limits the resistor accuracy and prevents further reduction of common-mode error. Moreover, they are costly. Utility Model Content

[0005] This invention provides a common-mode error calibration device for voltage and current sources, which can reduce the common-mode error of voltage and current sources at a lower cost.

[0006] According to one aspect of the present invention, a common-mode error calibration device for a voltage and current source is provided, the voltage and current source including at least one voltage and current channel, the voltage and current channel including a first output high-side, a first output low-side, and a first sensing high-side; the common-mode error calibration device includes:

[0007] A common-mode voltage output module includes a calibration channel, which includes a second high-side and a second low-side; the second high-side is used to output the common-mode voltage, and the second low-side is electrically connected to the first low-side output.

[0008] A current detection module, wherein a first terminal of the current detection module is electrically connected to a first output high-side plate of the voltage and current channel to be calibrated and a first sensing high-side plate of the voltage and current channel to be calibrated, and a second terminal of the current detection module is electrically connected to a second high-side plate, and the current detection module is used to detect the output current of the first output high-side plate;

[0009] The processing module is communicatively connected to the voltage and current source, the current detection module, and the common-mode voltage output module. It is used to configure the output of the second high end of the common-mode voltage output module, configure the expected output current value of the voltage and current channel to be calibrated, and calculate the calibration coefficient of the voltage and current channel to be calibrated based on the output current of the first high end of the output module.

[0010] Optionally, the voltage and current channel further includes a first sensing low end; the calibration channel further includes a second sensing high end and a second sensing low end.

[0011] The first low-output terminal of the voltage and current channel to be calibrated is electrically connected to the second low-output terminal and the second sensing low-output terminal; the first sensing low-output terminal of the voltage and current channel to be calibrated is electrically connected to the second low-output terminal and the second sensing low-output terminal.

[0012] Optionally, the voltage and current channel further includes a first controller, a first main digital-to-analog converter, a first error amplification stage, a first integration stage, a first power amplification stage, a first range resistor, a first differential amplification stage, a second differential amplification stage, and a first analog-to-digital converter;

[0013] The input terminal of the first main digital-to-analog converter is electrically connected to the first controller, the output terminal of the first main digital-to-analog converter is electrically connected to an input terminal of the first error amplifier stage, the output terminal of the first error amplifier stage is electrically connected to an input terminal of the first integrator stage, the output terminal of the first integrator stage is electrically connected to an input terminal of the first power amplifier stage, the output terminal of the first power amplifier stage is electrically connected to a first terminal of the first range resistor, and the second terminal of the first range resistor is electrically connected to the first high-side output.

[0014] The first input terminal of the first differential amplifier stage is electrically connected to the first terminal of the first range resistor, the second input terminal of the first differential amplifier stage is electrically connected to the second terminal of the first range resistor, and the output terminal of the first differential amplifier stage is electrically connected to an input terminal of the first error amplifier stage and an input terminal of the first analog-to-digital converter.

[0015] The first input terminal of the second differential amplifier stage is electrically connected to the first sensing high-end and the first output high-end; the second input terminal of the second differential amplifier stage is electrically connected to the first output low-end and the first sensing low-end; the output terminal of the second differential amplifier stage is electrically connected to an input terminal of the first analog-to-digital converter; and the output terminal of the first analog-to-digital converter is electrically connected to the first controller.

[0016] Optionally, the first output high-end and the first sensing high-end of all the voltage and current channels to be calibrated in the voltage and current source are electrically connected to the first terminal of the current detection module.

[0017] Alternatively, the common-mode error calibration device may further include: a multiplexing module;

[0018] The first output high-end and the first sensing high-end of each voltage and current channel to be calibrated in the voltage and current source are electrically connected to a first terminal of the multiplexing module. The second terminal of the multiplexing module is electrically connected to the first terminal of the current detection module. The control terminal of the multiplexing module is connected to a control signal. The multiplexing module is used to control the conduction state of its second terminal and its first terminal according to the control signal.

[0019] Optionally, the current detection module includes an ammeter.

[0020] Optionally, the common-mode voltage output module includes a source meter, and the source meter includes the calibration channel.

[0021] Optionally, the common-mode voltage output module includes a standard voltage and current source, and the standard voltage and current source includes the calibration channel.

[0022] Optionally, the calibration channel further includes:

[0023] The system comprises a second controller, a second main digital-to-analog converter, a second error amplifier stage, a second integration stage, a second power amplifier stage, a second range resistor, a third differential amplifier stage, a fourth differential amplifier stage, and a second analog-to-digital converter.

[0024] The input terminal of the second main digital-to-analog converter is electrically connected to the second controller, the output terminal of the second main digital-to-analog converter is electrically connected to one input terminal of the second error amplifier stage, the output terminal of the second error amplifier stage is electrically connected to one input terminal of the second integrator stage, the output terminal of the second integrator stage is electrically connected to the input terminal of the second power amplifier stage, the output terminal of the second power amplifier stage is electrically connected to the first terminal of the second range resistor, and the second terminal of the second range resistor is electrically connected to the second high-side plate.

[0025] The first input terminal of the third differential amplifier stage is electrically connected to the first terminal of the second range resistor, the second input terminal of the third differential amplifier stage is electrically connected to the second terminal of the second range resistor, and the output terminal of the third differential amplifier stage is electrically connected to an input terminal of the second error amplifier stage and an input terminal of the second analog-to-digital converter.

[0026] The first input terminal of the fourth differential amplifier stage is electrically connected to the second sensing high-side and the second sensing low-side, the second input terminal of the fourth differential amplifier stage is electrically connected to the second low-side and the second sensing low-side, the output terminal of the fourth differential amplifier stage is electrically connected to one input terminal of the second analog-to-digital converter, and the output terminal of the second analog-to-digital converter is electrically connected to the second controller.

[0027] Optionally, the processing module includes a microcontroller, DSP, FPGA, host computer, or central processing unit.

[0028] Optionally, the processing module is further configured to write the calibration coefficient into the voltage and current source.

[0029] The technical solution of this utility model embodiment employs a common-mode error calibration device for a voltage and current source, comprising: a common-mode voltage output module, including a calibration channel, the calibration channel including a second high-side and a second low-side; the second high-side is used to output the common-mode voltage, and the second low-side is electrically connected to a first output low-side; a current detection module, the first end of which is electrically connected to the first output high-side and the first sensing high-side of the voltage and current channel to be calibrated, and the second end of which is electrically connected to the second high-side, the current detection module being used to detect the output current of the first output high-side; and a processing module, communicatively connected to the voltage and current source, the current detection module, and the common-mode voltage output module, for configuring the output of the second high-side of the common-mode voltage output module, configuring the expected value of the output current of the voltage and current channel to be calibrated, and calculating the calibration coefficient of the voltage and current channel to be calibrated based on the output current of the first output high-side. This utility model improves the common-mode rejection capability through an improved common-mode error calibration device, and can reduce the common-mode error of the voltage and current source at a lower cost.

[0030] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 A circuit structure diagram of a common-mode error calibration device for a voltage and current source provided in this embodiment of the present invention;

[0033] Figure 2 A circuit diagram of another common-mode error calibration device for a voltage and current source provided in an embodiment of this utility model;

[0034] Figure 3 A circuit diagram of another common-mode error calibration device for a voltage and current source provided in an embodiment of this utility model;

[0035] Figure 4 A schematic diagram of the circuit structure of another common-mode error calibration device for a voltage and current source provided in this embodiment of the present invention. Detailed Implementation

[0036] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0037] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0038] Figure 1 A circuit structure diagram of a common-mode error calibration device for a voltage and current source provided in this embodiment of the present invention is shown below. Figure 1The voltage and current source 1 includes at least one voltage and current channel, which includes a first output high-side FH0, a first output low-side FL, and a first sensing high-side SH0. The common-mode error calibration device includes a common-mode voltage output module 2, a current detection module 3, and a processing module 4. The common-mode voltage output module 2 includes a calibration channel, which includes a second high-side JFH and a second low-side JFL. The second high-side JFH is used to output the common-mode voltage, and the second low-side JFL is electrically connected to the first output low-side FL. The first terminal of the current detection module 3 is electrically connected to the first output high-side FH0 and the first sensing high-side SH0 of the voltage and current channel to be calibrated, and the second terminal of the current detection module 3 is electrically connected to the second high-side JFH. The current detection module 3 is used to detect the output current of the first output high-side FH0. The processing module 4 is electrically connected to the voltage and current source 1, the current detection module 3, and the common-mode voltage output module 2. It is used to configure the output of the second high-side JFH of the common-mode voltage output module 2, configure the expected value of the output current of the voltage and current channel to be calibrated, and calculate the calibration coefficient of the voltage and current channel to be calibrated based on the output current of the first output high-side FH0.

[0039] Specifically, voltage and current source 1, also known as V / I source, includes at least one voltage and current channel. Each voltage and current channel can output a constant voltage or a constant current, and has constant current and constant voltage modes. When the voltage and current channel is in constant current mode, the current output from the first high-side output FH0 is constant, and the common-mode voltage of the first high-side output FH0 can be sensed through the first high-side sensing SH0, enabling the voltage and current channel to perform feedback control on the output of the first high-side output FH0. However, due to the influence of common-mode error, the current accuracy of the first high-side output FH0 of the voltage and current channel is relatively poor.

[0040] In this embodiment, the common-mode error calibration coefficient of the voltage and current channel to be calibrated can be obtained through a common-mode error calibration device. It is understood that each uncalibrated voltage and current channel in the voltage and current source can be a voltage and current channel to be calibrated. The calibration process is as follows: First, the processing module 4 controls the expected output current value of the voltage and current channel, that is, the expected output current value of the first output high-side FH0. More specifically, this expected output current value can be configured to be 0. It should also be noted that when the voltage and current channel has multiple current levels, each current level can be calibrated. That is, first, the voltage and current channel is configured as a level to be calibrated, and then the expected output current value is configured to be 0. Subsequently, the processing module 4 controls the second high-side JFH of the common-mode voltage output module 2 to provide various common-mode voltages to the first sensing high-side SH0 of the voltage and current channel to be calibrated, and uses the current detection module 3 to detect the output current corresponding to the first output high-side FH0. For example, under a 0A condition at a certain current level in the voltage and current channel, the common-mode voltage output module 2 is configured to output common-mode voltages (in Vcm) of -40V, -20V, 0V, 20V, 40V, 60V, and 80V respectively. Then, the output current corresponding to the first high-side FH0 is fitted with the common-mode voltage using the least squares method to calculate the calibration coefficient for the current current level (in Vcm). (This indicates that...) That is, .in, The common-mode voltage is The current detected by the current detection module. n represents the nth set of data, where n is less than or equal to N.

[0041] It should be noted that the calibration coefficients are calculated using conventional methods in the prior art, such as least squares fitting. This calculation method is not within the scope of protection of this utility model. This utility model protects the common-mode calibration device for voltage and current sources. The calculations involved in processing module 4 are not part of the technical solutions adopted by this utility model to solve technical problems.

[0042] In this embodiment, a common-mode error calibration device for a voltage and current source is constructed by simply setting up a common-mode voltage output module, a current detection module, and a processing module. This device improves common-mode rejection capability through hardware improvements and reduces common-mode error of the voltage and current source at a lower cost. Furthermore, in this embodiment, the first terminal of the current detection module 3 is electrically connected to the first output high-side FH0 and the first sensing high-side SH0, and the second terminal of the current detection module 3 is electrically connected to the second high-side JFH. This makes the current detected by the current detection module 3 more accurate, preventing inaccurate detection due to current shunting. The voltage sensed by the first sensing high-side SH0 of the first output high-side FH0 is also more accurate, unaffected by the internal resistance of the current detection module 3. In addition, the common-mode voltage output module 2 provides a current loop for the current output from the first output high-side FH0, offering the advantage of a simple circuit structure.

[0043] The technical solution of this embodiment employs a common-mode error calibration device for a voltage and current source, comprising: a common-mode voltage output module, including a calibration channel, the calibration channel including a second high-side and a second low-side; the second high-side is used to output the common-mode voltage, and the second low-side is electrically connected to a first low-side output; a current detection module, the first end of which is electrically connected to the first high-side output of the voltage and current channel to be calibrated and the first high-side sensing of the voltage and current channel to be calibrated, and the second end of which is electrically connected to the first low-side output; the current detection module is used to detect the output current of the first high-side output; and a processing module, communicatively connected to the voltage and current source, the current detection module, and the common-mode voltage output module, for configuring the output of the second high-side of the common-mode voltage output module, configuring the expected value of the output current of the voltage and current channel to be calibrated, and calculating the calibration coefficient of the voltage and current channel to be calibrated based on the output current of the first high-side output. By slightly improving the hardware in the voltage and current source to enhance the common-mode rejection capability, the common-mode error of the voltage and current source can be reduced at a lower cost.

[0044] Optionally, the processing module 4 includes a first calculation circuit, which is used to calculate the calibration coefficients using the least squares method. .

[0045] Optionally, the processing module 4 also includes a second calculation circuit, which is used to unify the calibration coefficients corresponding to different current levels. Specifically, the second calculation circuit includes a division unit that divides the calibration coefficient by the full-scale value of the current level, thereby unifying the dimensions of the calibration coefficients for each current level. Of course, other units can also be used to unify the calibration coefficients corresponding to different current levels.

[0046] It should be noted that after obtaining the calibration coefficient of the common-mode voltage of the voltage and current channels at the current current level, the corresponding calibration coefficient can be written to the voltage and current source through processing module 4. Alternatively, the calibration coefficient can also be written to the voltage and current source through other writing devices. After obtaining the calibration coefficient, the output current can be compensated using the calibration coefficient in subsequent output current calculations, for example... ,in, This is the current value after common-mode calibration. The current value set by the user. This refers to the measured common-mode voltage value. It should also be noted that, as those skilled in the art will understand, in a practical voltage and current source, the final output current is... The current after differential mode calibration is as follows: .in, and This is the current value after differential mode calibration. For differential mode calibration coefficients, This refers to differential mode offset. The differential mode calibration process and the formula for the final output current of the voltage and current source are well known to those skilled in the art. This invention only describes the common mode error calibration of the voltage and current source.

[0047] Optionally, continue to refer to Figure 1 To facilitate understanding, the specific structure of voltage and current source 1 will be briefly described. The voltage and current source includes a controller, a main digital-to-analog converter (DAC), and a main digital-to-analog converter (DAC). Figure 1 The first main DAC (hereinafter referred to as the main DAC) and the first error amplifier stage ( Figure 1The first main DAC (hereinafter referred to as the first NULL stage), first integrating stage, first power amplifier stage PA1, first range resistor Rs1, first differential amplifier stage U11, second differential amplifier stage U21, and first analog-to-digital converter ADC1 are connected. The input terminal of the first main DAC is electrically connected to the controller, the output terminal of the first main DAC is electrically connected to one input terminal of the first NULL stage, the output terminal of the first NULL stage is electrically connected to one input terminal of the first integrating stage, the output terminal of the first integrating stage is electrically connected to the input terminal of the first power amplifier stage PA1, the output terminal of the first power amplifier stage PA1 is electrically connected to the first terminal of the first range resistor Rs1, and the second terminal of the first range resistor Rs1 in the voltage and current path is electrically connected to the first high-side output FH0. The first input terminal (inverting input terminal) of the first differential amplifier stage U11 is connected to the first terminal of the first range resistor Rs1. The first differential amplifier stage U11 is electrically connected to the second input terminal (non-inverting input terminal) of the first range resistor Rs1, and the output terminal of the first differential amplifier stage U11 is electrically connected to an input terminal of the first NULL stage and an input terminal of the first analog-to-digital converter ADC1. The second differential amplifier stage U21 is electrically connected to the corresponding first sensing high-side SH0 and first sensing low-side SL points, and the output terminal of the second differential amplifier stage U21 is electrically connected to an input terminal of the first analog-to-digital converter ADC. The output terminal of the first analog-to-digital converter ADC is electrically connected to the first controller.

[0048] Specifically, in Figure 1 In the structure shown, the wavy line between two devices in the voltage and current source represents an indirect connection between the two devices. Figure 1This only demonstrates the specific architecture of the voltage and current channel in the voltage and current source. The resistance value of the first range resistor Rs1 varies depending on the current level. The specific working principle of the voltage and current channel in constant current mode is as follows: To stabilize the output current of the first high-side output FH0, the voltage and current channel divides the output current through the first range resistor Rs1, and then attenuates or amplifies it through differential operation by the first differential amplifier stage U11 to obtain the current feedback value. This current feedback value is fed back to the first NULL stage, which adjusts according to the current feedback signal to achieve the constant current function. Additionally, in constant current mode, the second differential amplifier stage U21 can sense the common-mode voltage of the first high-side output. As mentioned earlier, ideally, when the desired output current is 0, the current flowing through the first range resistor Rs1 is 0, then the voltage difference between the two input terminals of the first differential amplifier stage U11 is 0, and the current feedback value is 0. However, in reality, even if the differential input voltage difference of the first differential amplifier stage U11 is 0, the limited common-mode rejection capability of the first differential amplifier stage U11 itself and the inconsistent accuracy of the matching resistors will cause the output of the first differential amplifier stage U11 to be non-zero, resulting in a non-zero current feedback value. Consequently, the current flowing through the first range resistor Rs1 will also be non-zero, leading to an error. In this embodiment, during common-mode error calibration, the expected output current value is configured to be 0. Then, the current value output by the first high-side output FH0 is detected using the current detection module 3. This current value is the error of the current corresponding to the common-mode voltage. By fitting multiple sets of data, a fitting formula for the common-mode error and the current error can be obtained. Subsequently, the detected common-mode voltage can be substituted into the fitting formula to obtain the current error. This current error is then used to compensate for the user-set current value, thus obtaining the final command value of the current output by the controller.

[0049] In addition, it should be noted that the first differential amplifier stage and the second differential amplifier stage can be composed of various forms of differential amplifier circuits, and the specific circuit structure of the differential amplifier circuit is not specifically limited in this embodiment.

[0050] Optionally, in voltage and current source 1, the first controller may include a third calculation circuit. This third calculation circuit includes a multiplication unit and a subtraction unit. One end of the multiplication unit receives the common-mode voltage, and the other end receives a calibration coefficient. One end of the subtraction unit receives a user-set current value, and the other end is electrically connected to the output of the multiplication unit. The calculation circuit is used to calculate the current value after common-mode calibration, i.e., to calculate... .

[0051] Optionally, continue to refer to Figure 1The voltage and current channel also includes a first sensing low terminal SL; the calibration channel also includes a second sensing high terminal JSH and a second sensing low terminal JSL. The first output low terminal FL of the voltage and current channel to be calibrated is electrically connected to the second low terminal JFL and the second sensing low terminal JSL; the first sensing low terminal SL of the voltage and current channel to be calibrated is electrically connected to the second low terminal JFL and the second sensing low terminal JSL.

[0052] Specifically, the current output from the first high-side output FH0 flows through the second high-side JFH of the common-mode voltage output module 2 and then into the common-mode voltage output module 3. It then exits from the second low-side JFL and flows back into the first low-side output FL, thus forming a current loop. The first sensing high-side SH0 and the second sensing high-side SL sense the voltage of the first high-side output FH0, which is detected by the second differential amplifier stage U21. The voltage is then input to the first controller after passing through the first analog-to-digital converter ADC1. The first controller can perform feedback control on the voltage and current channels based on the sensed common-mode voltage. Similarly, in the common-mode voltage output module 2, the second sensing high-side JSH and the second sensing low-side JSL of the calibration channel are also used to sense the common-mode voltage output from the second high-side JFH. The common-mode voltage output module 2 can perform feedback control based on the sensed common-mode voltage of the second high-side JFH to stabilize the common-mode voltage output from the second high-side JFH.

[0053] Optionally, Figure 2 A circuit structure diagram of another common-mode error calibration device for a voltage and current source provided in this embodiment of the present invention is shown below. Figure 2 In the voltage and current source, the first high-end output and the first high-end sensing of all voltage and current channels to be calibrated are electrically connected to the first terminal of the current detection module.

[0054] Specifically, in this embodiment, the voltage and current source includes at least two current and voltage channels. In some implementations, no module of any of the different current and voltage channels is shared; in other implementations, the first controller of the different current and voltage channels can be shared, i.e. Figure 2 The structure shown is illustrated; in some embodiments, the first analog-to-digital converter ADC1 of different voltage and current channels can be shared; in other embodiments, the first main DAC of different voltage and current channels can be shared. It should be noted that the first NULL stage, first integrating stage, first power amplification stage PA1, first differential amplification stage U11, second differential amplification stage U21, and first range resistor Rs1 of different voltage and current channels cannot be shared. By electrically connecting the first high-side output FH0 of all voltage and current channels to the first terminal of the current detection module 3, and electrically connecting the first high-side sensing SH0 of all voltage and current channels to the first terminal of the current detection module 3, a single common-mode voltage output module 2 can provide common-mode voltage and output current loops for all voltage and current channels to be calibrated.

[0055] Optionally, Figure 3 A circuit structure diagram of another common-mode error calibration device for a voltage and current source provided in this embodiment of the present invention is shown below. Figure 3 The common-mode error calibration device also includes a multiplexing module 5. The first high-side output FH0 and the first high-side sensing SH0 of each voltage and current channel to be calibrated in the voltage and current source 1 are electrically connected to a corresponding first terminal of the multiplexing module 5. The first high-side output FH0 of different voltage and current channels are electrically connected to different first terminals of the multiplexing module 5. The second terminal of the multiplexing module 5 is electrically connected to the first terminal of the current detection module 3. A control signal is received at the control terminal of the multiplexing module 5, and the multiplexing module 5 is used to control the conduction state of its second terminal and its first terminal according to the control signal.

[0056] Specifically, in this embodiment, the control terminal of the multiplexing module 5 can be electrically connected to the processing module 4, and the multiplexing module 5 is controlled by the processing module 4. When calibrating a certain voltage and current channel, the first terminal of the multiplexing module 5 corresponding to that voltage and current channel can be electrically connected to the second terminal of the corresponding multiplexing module 5, so that the second high-side JFH is electrically connected to the first high-side output FH0 of the corresponding voltage and current channel; while the first high-side output FH0 of other voltage and current channels to be calibrated is not connected to the corresponding second high-side JFH. Thus, multiple voltage and current channels can be calibrated with a single wiring, that is, there is no need to change the wiring method to calibrate another voltage and current channel after calibrating one voltage and current channel, which can save wiring time and ensure that the common-mode voltage output module 2 is in a continuous and stable working state, avoiding the instability of the common-mode voltage output module 2 from affecting the calibration process. In addition, by setting the multiplexing module 5, it is also possible to avoid the mutual interference of other voltage and current modules and the common-mode voltage output module when calibrating one voltage and current module, thereby avoiding affecting the calibration results.

[0057] Optionally, in some other embodiments, the common-mode error calibration device includes two multiplexing modules. One module corresponds to the first sensing high-end and the first output high-end, and is defined as the first multiplexing module. The other module corresponds to the first sensing low-end and the first output low-end, and is defined as the second multiplexing module. That is, the first output low-end and the first sensing low-end of the voltage / current channel are electrically connected to one first terminal of the second multiplexing module, the first output low-ends of different voltage / current channels are electrically connected to different first terminals of the second multiplexing module, and the second sensing low-end and the second output low-end are electrically connected to the second terminal of the second multiplexing module. The control terminal of the second multiplexing module receives the same control signal as the control terminal of the first multiplexing module. The second multiplexing module is used to control the conduction state of its second terminal and its first terminal according to the control signal. In other words, when calibrating a voltage / current channel, the first terminal of the first multiplexing module corresponding to that voltage / current channel can be electrically connected to the second terminal of the corresponding first multiplexing module, and the first terminal of the second multiplexing module corresponding to that voltage / current channel can be electrically connected to the second terminal of the corresponding second multiplexing module. By setting up a second multiplexing module, it is possible to further avoid interference between other voltage and current modules and the common-mode voltage output module when calibrating one voltage and current module, thereby avoiding affecting the calibration results.

[0058] Optionally, the current detection module 3 includes an ammeter. In this embodiment, the ammeter is a communication-enabled ammeter that can send the detected output current to the processing module 4. Using an ammeter to implement the function of the current detection module 3 results in a simple circuit structure, accurate measurement, and low cost.

[0059] Optionally, the common-mode voltage output module 2 includes a source meter, which includes a calibration channel. The source meter is, for example, a device capable of outputting a stable common-mode voltage, such as a digital source meter.

[0060] In some other embodiments, alternatively, refer to Figure 4 , Figure 4 This is a schematic diagram of the circuit structure of another common-mode error calibration device for a voltage and current source provided in an embodiment of the present invention. In this embodiment, the common-mode voltage output module 2 includes a standard voltage and current source 21, which includes a calibration channel.

[0061] Specifically, the standard voltage and current source 21 is a voltage and current source with the same structure as the voltage and current source 1 to be calibrated. Furthermore, the standard voltage and current source 21 is a voltage-calibrated source capable of outputting a stable common-mode voltage. The standard voltage and current source 21 can be calibrated using a source meter.

[0062] Optionally, continue to refer to Figure 4The structure of the standard voltage and current source 21 is the same as that of the voltage and current source 1. In the standard voltage and current source 21, the calibration channel also includes: a second controller, a second main digital-to-analog converter (DAC), and a third main digital-to-analog converter (DAC). Figure 4 (represented by the second main DAC), the second error amplifier stage ( Figure 4 The circuit consists of a second NULL stage, a second integrating stage, a second power amplifier stage PA2, a second range resistor Rs2, a third differential amplifier stage U12, a fourth differential amplifier stage U22, and a second analog-to-digital converter ADC2. The input of the second main digital-to-analog converter is electrically connected to the second controller; the output of the second main digital-to-analog converter is electrically connected to one input of the second error amplifier stage; the output of the second error amplifier stage is electrically connected to one input of the second integrating stage; the output of the second integrating stage is electrically connected to the input of the second power amplifier stage; the output of the second power amplifier stage is electrically connected to the first terminal of the second range resistor; and the second terminal of the second range resistor is electrically connected to the second high-side plate. The third differential amplifier... The first input terminal (inverting input terminal) of the large-scale stage is electrically connected to the first terminal of the second range resistor. The second input terminal (non-inverting input terminal) of the third differential amplifier stage is electrically connected to the second terminal of the second range resistor. The output terminal of the third differential amplifier stage is electrically connected to one input terminal of the second error amplifier stage and one input terminal of the second analog-to-digital converter. The first input terminal (inverting input terminal) of the fourth differential amplifier stage is electrically connected to the second high-side sensor and the second high-side sensor. The second input terminal (non-inverting input terminal) of the fourth differential amplifier stage is electrically connected to the second low-side sensor and the second low-side sensor. The output terminal of the fourth differential amplifier stage is electrically connected to one input terminal of the second analog-to-digital converter. The output terminal of the second analog-to-digital converter is electrically connected to the second controller. The working principle of the calibration channel in the standard voltage and current source is the same as that of the voltage and current channel in the voltage and current source, and will not be described again here.

[0063] It should be noted that in the above embodiment, the first input terminal of the differential amplifier stage is an inverting input terminal and the second input terminal is a non-inverting input terminal. In other embodiments, the first input terminal of the differential amplifier stage can be a non-inverting input terminal and the second input terminal can be an inverting input terminal. The specific settings can be made according to the actual design and are not specifically limited here.

[0064] In addition, it should be noted that the fourth differential amplifier stage and the third differential amplifier stage can be composed of various forms of differential amplifier circuits, and the specific circuit structure of the differential amplifier circuit is not specifically limited in this embodiment.

[0065] Optionally, the processing module 4 may include a microcontroller, a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), a host computer, or a central processing unit.

[0066] It should be understood that the various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this utility model can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this utility model can be achieved, and this is not limited herein.

[0067] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A common-mode error calibration device for a voltage and current source, characterized in that, The voltage and current source includes at least one voltage and current channel, and the voltage and current channel includes a first output high-side, a first output low-side, and a first sensing high-side. The common-mode error calibration device includes: A common-mode voltage output module includes a calibration channel, which includes a second high-side and a second low-side; the second high-side is used to output the common-mode voltage, and the second low-side is electrically connected to the first low-side output. A current detection module, wherein a first terminal of the current detection module is electrically connected to a first output high-side plate of the voltage and current channel to be calibrated and a first sensing high-side plate of the voltage and current channel to be calibrated, and a second terminal of the current detection module is electrically connected to a second high-side plate, and the current detection module is used to detect the output current of the first output high-side plate; The processing module is communicatively connected to the voltage and current source, the current detection module, and the common-mode voltage output module. It is used to configure the output of the second high end of the common-mode voltage output module, configure the expected output current value of the voltage and current channel to be calibrated, and calculate the calibration coefficient of the voltage and current channel to be calibrated based on the output current of the first high end of the output module.

2. The common-mode error calibration device for voltage and current sources according to claim 1, characterized in that, The voltage and current channel further includes a first sensing low end; the calibration channel further includes a second sensing high end and a second sensing low end. The first low-output terminal of the voltage and current channel to be calibrated is electrically connected to the second low-output terminal and the second sensing low-output terminal; the first sensing low-output terminal of the voltage and current channel to be calibrated is electrically connected to the second low-output terminal and the second sensing low-output terminal.

3. The common-mode error calibration device for voltage and current sources according to claim 2, characterized in that, The voltage and current channels further include a first controller, a first main digital-to-analog converter, a first error amplification stage, a first integration stage, a first power amplification stage, a first range resistor, a first differential amplification stage, a second differential amplification stage, and a first analog-to-digital converter; The input terminal of the first main digital-to-analog converter is electrically connected to the first controller, the output terminal of the first main digital-to-analog converter is electrically connected to an input terminal of the first error amplifier stage, the output terminal of the first error amplifier stage is electrically connected to an input terminal of the first integrator stage, the output terminal of the first integrator stage is electrically connected to an input terminal of the first power amplifier stage, the output terminal of the first power amplifier stage is electrically connected to a first terminal of the first range resistor, and the second terminal of the first range resistor is electrically connected to the first high-side output. The first input terminal of the first differential amplifier stage is electrically connected to the first terminal of the first range resistor, the second input terminal of the first differential amplifier stage is electrically connected to the second terminal of the first range resistor, and the output terminal of the first differential amplifier stage is electrically connected to an input terminal of the first error amplifier stage and an input terminal of the first analog-to-digital converter. The first input terminal of the second differential amplifier stage is electrically connected to the first sensing high-end and the first output high-end; the second input terminal of the second differential amplifier stage is electrically connected to the first output low-end and the first sensing low-end; the output terminal of the second differential amplifier stage is electrically connected to an input terminal of the first analog-to-digital converter; and the output terminal of the first analog-to-digital converter is electrically connected to the first controller.

4. The common-mode error calibration device for voltage and current sources according to claim 2, characterized in that, The first output high end and the first sensing high end of all the voltage and current channels to be calibrated in the voltage and current source are electrically connected to the first terminal of the current detection module. Alternatively, the common-mode error calibration device may further include: a multiplexing module; The first output high-end and the first sensing high-end of each voltage and current channel to be calibrated in the voltage and current source are electrically connected to a first terminal of the multiplexing module. The second terminal of the multiplexing module is electrically connected to the first terminal of the current detection module. The control terminal of the multiplexing module is connected to a control signal. The multiplexing module is used to control the conduction state of its second terminal and its first terminal according to the control signal.

5. The common-mode error calibration device for voltage and current sources according to claim 1, characterized in that, The current detection module includes an ammeter.

6. The common-mode error calibration device for voltage and current sources according to claim 2, characterized in that, The common-mode voltage output module includes a source meter, and the source meter includes the calibration channel.

7. The common-mode error calibration device for voltage and current sources according to claim 2, characterized in that, The common-mode voltage output module includes a standard voltage and current source, and the standard voltage and current source includes the calibration channel.

8. The common-mode error calibration device according to claim 7, characterized in that, The calibration channel also includes: The system comprises a second controller, a second main digital-to-analog converter, a second error amplifier stage, a second integration stage, a second power amplifier stage, a second range resistor, a third differential amplifier stage, a fourth differential amplifier stage, and a second analog-to-digital converter. The input terminal of the second main digital-to-analog converter is electrically connected to the second controller, the output terminal of the second main digital-to-analog converter is electrically connected to one input terminal of the second error amplifier stage, the output terminal of the second error amplifier stage is electrically connected to one input terminal of the second integrator stage, the output terminal of the second integrator stage is electrically connected to the input terminal of the second power amplifier stage, the output terminal of the second power amplifier stage is electrically connected to the first terminal of the second range resistor, and the second terminal of the second range resistor is electrically connected to the second high-side plate. The first input terminal of the third differential amplifier stage is electrically connected to the first terminal of the second range resistor, the second input terminal of the third differential amplifier stage is electrically connected to the second terminal of the second range resistor, and the output terminal of the third differential amplifier stage is electrically connected to an input terminal of the second error amplifier stage and an input terminal of the second analog-to-digital converter. The first input terminal of the fourth differential amplifier stage is electrically connected to the second sensing high-side and the second sensing low-side, the second input terminal of the fourth differential amplifier stage is electrically connected to the second low-side and the second sensing low-side, the output terminal of the fourth differential amplifier stage is electrically connected to one input terminal of the second analog-to-digital converter, and the output terminal of the second analog-to-digital converter is electrically connected to the second controller.

9. The common-mode error calibration device for voltage and current sources according to claim 1, characterized in that, The processing module includes a microcontroller, DSP, FPGA, host computer, or central processing unit.

10. The common-mode error calibration device for voltage and current sources according to claim 1, characterized in that, The processing module is also used to write the calibration coefficient into the voltage and current source.

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