A low noise DC amplifier module with static and dynamic error adjustment

Abstract

The application relates to a low-noise direct-current amplifier module with static and dynamic error adjustment, and belongs to the field of low-noise direct-current amplifiers. The low-noise amplifier is used for weak direct-current voltage signal measurement, a plurality of discrete JFET field effect tubes are connected in parallel to form an input stage of the low-noise amplifier, noise interference is reduced, and extremely high input impedance can be provided by utilizing the characteristic that the gate current of the JFET field effect tube is basically zero; the inherent error of the low-noise amplifier module is suppressed through a proportional current mirror of the low-noise amplifier module, an ADC (analog-to-digital conversion) module and a DAC (digital-to-analog conversion) module; dynamic error of the amplifier module is compensated through a negative feedback system composed of the ADC module and the DAC module by controlling timing, and the problems that solid-state error caused by the discrete structure of the amplifier and dynamic error caused by stress change and temperature change during long-time measurement affect precise amplification and measurement of the direct-current voltage signal are solved.

Description

Technical Field

[0001] This invention belongs to the field of amplifier technology, specifically a low-noise DC amplifier module with static and dynamic error adjustment. Background Technology

[0002] Amplifiers are mainly used for high-precision amplification of voltage signals. When amplifying weak voltage signals, integrated operational amplifiers and JFET discrete devices can be used to build amplifiers. However, integrated operational amplifiers cannot simultaneously meet the requirements of low noise and high input impedance, and are not suitable for general-purpose instrument design. JFETs have high input impedance and low noise characteristics, and building discrete amplifiers using JFETs can solve the contradiction between high input impedance and low noise.

[0003] The inherent error generated by the amplifier is mainly composed of the offset voltage generated by the amplifier. The error signal characteristics are DC voltage signal and low frequency voltage signal. Since the amplifier adopts a JFET discrete structure design, the offset voltage generated by it is the main inherent error. The dynamic error generated by the amplifier is caused by the change of device parameters due to stress and temperature changes under long-term measurement, resulting in changes in the amplifier module transfer function.

[0004] Because the amplifier uses a JFET discrete structure design, the mismatch of device parameters in the differential circuit under the discrete structure will cause offset voltage. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a low-noise DC amplifier module with static and dynamic error adjustment, so as to solve the problems of solid-state error caused by the discrete structure of the amplifier and dynamic error caused by stress and temperature changes during long-term measurement in the existing DC voltage measurement, which affect the precise amplification and measurement of DC voltage signals.

[0006] This invention is implemented as follows:

[0007] A low-noise DC amplifier module with static and dynamic error adjustment includes: a switching module, a power management circuit, a low-noise amplifier, a current mirror scaling module, an ADC analog-to-digital converter module, a DAC digital-to-analog converter module, a reference circuit, and a digital core control module; wherein:

[0008] The switching module switches the low-noise amplifier to either an internal ground signal or an external measurement signal.

[0009] The power management circuit is used to provide power with different rated voltage values ​​to other circuits;

[0010] The low-noise amplifier is used to amplify weak DC voltage signals with low noise and to adjust the input voltage signal to ensure that the ADC analog-to-digital conversion module does not exceed its range.

[0011] The current mirror scaling module is used to connect to a low-noise amplifier to perform coarse-scale adjustment of the inherent error.

[0012] The ADC analog-to-digital converter module is used to measure the output of the amplifier circuit, and to perform analog-to-digital conversion and output to the digital core control module;

[0013] The DAC digital-to-analog converter module is connected to the output of the low-noise amplifier to perform fine-scale adjustment and dynamic error compensation of the amplifier error.

[0014] The reference circuit provides a stable reference voltage for the ADC analog-to-digital converter module, the DAC digital-to-analog converter module, and the control algorithm.

[0015] The digital core control module is used for the timing control of the coarse-scale error adjustment control, fine-scale error adjustment, dynamic compensation value calculation and switch switching modules.

[0016] Furthermore, the low-noise amplifier adopts a discrete parallel JFET pair structure as the input stage of the amplifier module, including: JFET field-effect transistors Q1, Q2, Q9, and Q10. JFET field-effect transistors Q1 and Q9 are connected in parallel. The drains of JFET field-effect transistors Q1 and Q9 are connected to the emitter of transistor Q7. The collector of transistor Q7 is connected to the collector of transistor Q5. The emitter of transistor Q5 is connected to resistor R5 and then to the positive power supply.

[0017] JFET field-effect transistors Q2 and Q10 are connected in parallel. The drains of JFET field-effect transistors Q2 and Q10 are connected to the emitter of transistor Q6. The collector of transistor Q6 is connected to the collector of transistor Q4. The emitter of transistor Q4 is connected to resistor R4 and then to the positive power supply.

[0018] The sources of JFETs Q1, Q2, Q9, and Q10 are connected to the drain of JFET Q8. The gate of JFET Q8 is connected to the output of amplifier U1. The non-inverting input of amplifier U1 is connected to the negative power supply through diode D1. The inverting input of amplifier U1 is connected to the source of JFET Q8 and then connected to resistor R3 before being connected to the negative power supply.

[0019] The base of transistor Q5 is connected to the emitter of transistor Q3, the collector of transistor Q3 is connected to the base of transistor Q7, and the base of transistor Q7 is connected to the base of transistor Q6. The collector of transistor Q4 is connected to the non-inverting input of amplifier U2 and the base of transistor Q3, the inverting input of amplifier U2 is connected to the collector of transistor Q7, and the output of amplifier U2 is grounded through resistors R6 and R8. Resistors R6 and R8 are connected to the gates of JFET field-effect transistors Q2 and Q10.

[0020] Furthermore, the current mirror proportional adjustment module replaces resistor R4 and includes multiple parallel resistors with individual switches. By connecting them with different resistance values, the current in the differential branch is adjusted, and the inherent error of the low-noise DC amplifier module is coarsely adjusted.

[0021] Furthermore, during coarse-scale adjustment, the switch switching module switches the low-noise amplifier to the internal ground signal, the current mirror proportional adjustment module connects different resistor combinations according to different control words, the ADC analog-to-digital conversion module collects the output voltage, the digital core control module records the voltage value of the control word and compares the absolute values. The control word with the smaller absolute value is ultimately retained. At this time, the inherent error is the minimum error after coarse-scale adjustment.

[0022] Furthermore, after coarse-scale adjustment, the inherent error after coarse-scale adjustment is optimized by fine-scale using the ADC analog-to-digital converter module and the DAC digital-to-analog converter module. The switching module grounds the input of the low-noise amplifier, the ADC analog-to-digital converter module collects the output voltage of the low-noise amplifier as the inherent error to be fine-scale adjusted, and sends the collected inherent error to the digital core control module. The digital core control module encodes the data from the ADC analog-to-digital converter module and sends it to the DAC digital-to-analog converter module. The DAC digital-to-analog converter module outputs a compensation signal and connects it to the output of the amplifier module. The DAC digital-to-analog converter module is used as a negative feedback path, and the output compensation value of the DAC analog-to-digital converter module at this time is taken as the true value.

[0023] Furthermore, the switching circuit adjusts and switches to perform fixed-period measurements on external and internal ground signals by controlling the timing.

[0024] Furthermore, after the fine-scale adjustment is completed, the digital core control module sends the control timing command to the switch switching module, and the switch switching module connects the external measurement signal and the internal ground signal according to the timing sent by the digital core control module;

[0025] When the switch switching module receives the internal ground signal, the digital core control module calculates the difference between the measured data of the ADC analog-to-digital converter module and the true value, converts the difference into a compensation value and transmits it to the DAC digital-to-analog converter module. The DAC digital-to-analog converter module receives the compensation value and adjusts it based on the original true value.

[0026] When an external measurement signal is connected to the switching module, the DAC analog-to-digital converter module outputs the adjusted true value as a compensation value to the output of the amplifier module.

[0027] A method for operating a low-noise DC amplifier module with static and dynamic error adjustment includes the following steps:

[0028] Step 1: Switch the low-noise amplifier to the internal ground signal using the switch switching module, adjust the resistor array of the current mirror proportional adjustment module to perform coarse-scale adjustment of the inherent error, record the voltage value of the control word through the digital core control module and compare the absolute values. The control word with the smaller absolute value is finally retained. At this time, the inherent error is the minimum error after coarse-scale adjustment.

[0029] Step 2: After coarse scale error adjustment is completed, the inherent error after coarse scale adjustment is adjusted using the ADC analog-to-digital converter module and the DAC digital-to-analog converter module. The switching module grounds the input of the low-noise amplifier. The ADC analog-to-digital converter module collects the output voltage of the low-noise amplifier as the inherent error to be adjusted in fine scale and sends the collected inherent error to the digital core control module. The digital core control module encodes the data from the ADC analog-to-digital converter module and sends it to the DAC digital-to-analog converter module. The DAC digital-to-analog converter module outputs a compensation signal and connects it to the output of the amplifier module. The DAC digital-to-analog converter module is used as a negative feedback path, and the output compensation value of the DAC analog-to-digital converter module at this time is taken as the true value.

[0030] Step 3: After the fine ruler error adjustment is completed, the digital core control module sends the control timing command to the switch adjustment switching circuit. The switch module connects the external measurement signal and the internal ground signal according to the control timing.

[0031] Step 4: When the switch adjustment circuit is connected to the ground signal, and when the switch switching module is connected to the internal ground signal, the digital core control module calculates the difference between the ADC analog-to-digital converter module's measured data and the true value, converts the difference into a compensation value, and transmits it to the DAC digital-to-analog converter module. The DAC digital-to-analog converter module receives the compensation value and adjusts based on the original true value.

[0032] When an external measurement signal is connected to the switching module, the DAC analog-to-digital converter module outputs the adjusted true value as a compensation value to the output of the amplifier module.

[0033] Compared with the prior art, the beneficial effects of this invention are as follows:

[0034] This invention uses a DAC circuit and a proportional adjustment circuit with a proportional current mirror to adjust the inherent and dynamic errors of the amplifier, achieving precise amplification of DC voltage signals. It solves the problem of test accuracy interference caused by solid-state and dynamic errors in existing measurement amplifiers and systems. Attached Figure Description

[0035] Figure 1 This is an overall structural block diagram provided in an embodiment of the present invention.

[0036] Figure 2 This is an amplifier circuit topology diagram provided in an embodiment of the present invention.

[0037] Figure 3 This is a topology diagram of the current mirror and proportional adjustment circuit provided in an embodiment of the present invention.

[0038] Figure 4 This is a flowchart of the inherent coarse-scale error optimization provided in the embodiments of the present invention.

[0039] Figure 5 This is a flowchart of the fine-scale error optimization process for inherent errors provided in the embodiments of the present invention.

[0040] Figure 6 This is a timing diagram illustrating the switch control provided in an embodiment of the present invention.

[0041] Figure 7 This is a flowchart of dynamic error adjustment provided in an embodiment of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0043] Referring to Figure 1, a low-noise DC amplifier module with static and dynamic error adjustment is disclosed. This low-noise DC amplifier module includes: a switching module, a power management circuit, a low-noise amplifier, a current mirror scaling module, an ADC analog-to-digital converter module, a DAC digital-to-analog converter module, a reference circuit, and a digital core control module; wherein:

[0044] The switching module switches the low-noise amplifier to either an internal ground signal or an external measurement signal.

[0045] Power management circuits are used to provide power to other circuits with different rated voltage values;

[0046] The low-noise amplifier is used to amplify weak DC voltage signals with low noise and to adjust the input voltage signal so that the ADC analog-to-digital conversion module does not exceed its range;

[0047] The current mirror scaling module is used to connect to a low-noise amplifier to coarsely adjust the inherent error.

[0048] The ADC analog-to-digital converter module is used to measure the output of the amplifier circuit, and to perform analog-to-digital conversion and output to the digital core control module;

[0049] The DAC digital-to-analog converter module is connected to the output of the low-noise amplifier to perform fine-scale adjustment and dynamic error compensation of the amplifier error;

[0050] The reference circuit provides a stable reference voltage for the ADC analog-to-digital converter module, the DAC digital-to-analog converter module, and the control algorithm;

[0051] The digital core control module is used for the timing control of coarse-scale error adjustment, fine-scale error adjustment, dynamic compensation value calculation, and switch switching modules.

[0052] The amplifier module of this invention is mainly used for low-noise and high-precision amplification of DC voltage signals. The inherent error characteristics of the amplifier module are manifested in DC voltage characteristics, which will cause errors in the voltage measurement results of the amplifier module; the dynamic error characteristics are random fluctuations, which reduce the stability of the amplifier module when measuring voltage.

[0053] like Figure 2 As shown, the low-noise amplifier consists of two parts: discrete JFET pairs form the first-stage amplifier circuit as the input stage, and an integrated operational amplifier forms the second-stage amplifier circuit. These two parts constitute a two-stage open-loop amplifier, and the entire amplifier module achieves two-stage closed-loop negative feedback. This structure gives the amplifier module high input impedance and low noise characteristics. The input impedance and noise expressions of the amplifier under the condition of N JFETs connected in parallel are:

[0054]

[0055]

[0056] The amplifier module uses a discrete parallel JFET pair structure as its input stage, including: JFET field-effect transistors Q1, Q2, Q9, and Q10. JFET field-effect transistors Q1 and Q9 are connected in parallel. The drains of JFET field-effect transistors Q1 and Q9 are connected to the emitter of transistor Q7. The collector of transistor Q7 is connected to the collector of transistor Q5. The emitter of transistor Q5 is connected to the positive power supply after being connected to resistor R5.

[0057] JFET field-effect transistors Q2 and Q10 are connected in parallel. The drains of JFET field-effect transistors Q2 and Q10 are connected to the emitter of transistor Q6. The collector of transistor Q6 is connected to the collector of transistor Q4. The emitter of transistor Q4 is connected to resistor R4 and then to the positive power supply.

[0058] The sources of JFETs Q1, Q2, Q9, and Q10 are connected to the drain of JFET Q8. The gate of JFET Q8 is connected to the output of amplifier U1. The non-inverting input of amplifier U1 is connected to the negative power supply through diode D1. The inverting input of amplifier U1 is connected to the source of JFET Q8 and then connected to resistor R3 before being connected to the negative power supply.

[0059] The base of transistor Q5 is connected to the emitter of transistor Q3, the collector of transistor Q3 is connected to the base of transistor Q7, and the base of transistor Q7 is connected to the base of transistor Q6. The collector of transistor Q4 is connected to the non-inverting input of amplifier U2 and the base of transistor Q3, the inverting input of amplifier U2 is connected to the collector of transistor Q7, and the output of amplifier U2 is grounded through resistors R6 and R8. Resistors R6 and R8 are connected to the gates of JFET field-effect transistors Q2 and Q10.

[0060] like Figure 3 and Figure 4 As shown, due to the discrete JFET pair design used in the amplifier module, the offset voltage caused by parameter mismatch of the JFETs under non-ideal conditions is the main factor contributing to the inherent error of the amplifier module. The inherent offset error of the amplifier is:

[0061] V OS =V OS1 +V OSC

[0062] Where V OS1 V is the offset voltage caused by mismatch in the JFET device. OSC Compensation voltage generated by the current mirror

[0063] When the amplifier module is powered on, the digital control core will control the connection of the proportional resistor of the proportional current mirror. The design formula for the proportional resistor is:

[0064] R 4_i =R 4_1 ·2 i-1

[0065] The current mirror proportional adjustment module replaces resistor R4 and includes multiple parallel resistors with individual switches. By connecting them with different resistance values, it adjusts the current in the differential branch and performs coarse-scale adjustment of the inherent error of the low-noise DC amplifier module.

[0066] In this embodiment, the circuit has 64 offset adjustment scales, where i takes integer values ​​from 1 to 6. This design ensures good adjustment capability of the circuit offset voltage, and the resistance values ​​are also conventional, making it easy to implement. During coarse-scale adjustment, the switching module switches the low-noise amplifier's connection to the internal ground signal. The current mirror proportional adjustment module connects different resistor combinations according to different control words. During the proportional resistor adjustment of the current mirror, 64 intervals correspond to 64 control words. The digital core control module adjusts from control word 0 to control word 63. Simultaneously, the ADC analog-to-digital conversion module collects the amplifier module's output, using the absolute value of the collected signal as the inherent error. When control word A changes to control word B, the inherent error changes. The inherent errors corresponding to the 64 control words are recorded. These inherent errors are compared, and the smallest inherent error is selected as the optimal coarse-scale inherent error. The resistor value corresponding to the optimal coarse-scale inherent error is selected; this resistor value is the optimal resistor selection under coarse-scale adjustment. After prolonged operation, the components in the amplifier module age, resulting in a significant inherent error offset. Therefore, coarse-scale adjustment of the inherent offset is required each time the module is powered on.

[0067] See Figure 5 After coarse-scale optimization, the inherent error of the amplifier module is approximately between 100μV and 10μV. The next step involves using an ADC (Analog-to-Digital Converter) and a DAC (Digital-to-Analog Converter) to fine-scale optimize the inherent error after coarse-scale adjustment. The switching module grounds the input of the low-noise amplifier, and the ADC collects the output voltage of the low-noise amplifier as the inherent error to be fine-scale adjusted. This collected inherent error is then sent to the digital core control module. The digital core control module encodes the data from the ADC and sends it to the DAC. The DAC outputs a compensation signal, which is then connected to the output of the low-noise amplifier, acting as a negative feedback path. The DAC's output range is 5V, and its minimum output voltage is 298nV, which reduces the inherent error of the low-noise amplifier output to approximately 1μV. The compensated output value of the DAC at this point is taken as the true value. This completes the static error adjustment of the amplifier module.

[0068] Figure 6 and Figure 7After the static inherent error adjustment is completed, dynamic error adjustment will be performed. The switching module will supply the external measured signal to the input of the low-noise amplifier at 90% of the output rate of the ADC module, and the internal ground signal to the input of the low-noise amplifier at 10% of the output rate. When the ground signal is connected to the input of the low-noise amplifier, the ADC module will acquire the output signal of the amplifier module and transmit it to the digital core control module. The digital core control module will then compare this value with the inherent error after fine-scale adjustment, convert the difference into a compensation value, and transmit it to the DAC module. The DAC module will receive the compensation value and make fine adjustments based on the original true value. When the switching module supplies the measured signal to the input of the amplifier module, the DAC module will maintain the compensation value output to the output of the low-noise amplifier. During this time, the dynamic error of the circuit will always be in a compensated state.

[0069] The present invention also provides a method for operating a low-noise DC amplifier module with static and dynamic error adjustment, comprising the following steps:

[0070] Step 1: Switch the low-noise amplifier to the internal ground signal using the switch switching module, adjust the resistor array of the current mirror proportional adjustment module to perform coarse-scale adjustment of the inherent error, record the voltage value of the control word through the digital core control module and compare the absolute values. The control word with the smaller absolute value is finally retained. At this time, the inherent error is the minimum error after coarse-scale adjustment.

[0071] Step 2: After coarse scale error adjustment is completed, the inherent error after coarse scale adjustment is adjusted using the ADC analog-to-digital converter module and the DAC digital-to-analog converter module. The switching module grounds the input of the low-noise amplifier. The ADC analog-to-digital converter module collects the output voltage of the low-noise amplifier as the inherent error to be adjusted in fine scale and sends the collected inherent error to the digital core control module. The digital core control module encodes the data from the ADC analog-to-digital converter module and sends it to the DAC digital-to-analog converter module. The DAC digital-to-analog converter module outputs a compensation signal and connects it to the output of the amplifier module. The DAC digital-to-analog converter module is used as a negative feedback path, and the output compensation value of the DAC analog-to-digital converter module at this time is taken as the true value.

[0072] Step 3: After the fine ruler error adjustment is completed, the digital core control module sends the control timing command to the switch adjustment switching circuit. The switch module connects the external measurement signal and the internal ground signal according to the control timing.

[0073] Step 4: When the switch adjustment circuit is connected to the ground signal, and when the switch switching module is connected to the internal ground signal, the digital core control module calculates the difference between the ADC analog-to-digital converter module's measured data and the true value, converts the difference into a compensation value, and transmits it to the DAC digital-to-analog converter module. The DAC digital-to-analog converter module receives the compensation value and adjusts based on the original true value.

[0074] When an external measurement signal is connected to the switching module, the DAC analog-to-digital converter module outputs the adjusted true value as a compensation value to the output of the amplifier module.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low noise DC amplifier module with static and dynamic error adjustment, characterized by, The low-noise DC amplifier module includes: a switching module, a power management circuit, a low-noise amplifier, a current mirror ratio adjustment module, an ADC analog-to-digital converter module, a DAC digital-to-analog converter module, a reference circuit, and a digital core control module; wherein: The switching module switches the low-noise amplifier to either an internal ground signal or an external measurement signal. The power management circuit is used to provide power with different rated voltage values ​​to other circuits; The low-noise amplifier is used to amplify weak DC voltage signals with low noise and to adjust the input voltage signal to ensure that the ADC analog-to-digital conversion module does not exceed its range. The current mirror scaling module is used to connect to a low-noise amplifier to perform coarse-scale adjustment of the inherent error. The ADC analog-to-digital converter module is used to measure the output of the amplifier circuit, and to perform analog-to-digital conversion and output to the digital core control module; The DAC digital-to-analog converter module is connected to the output of the low-noise amplifier to perform fine-scale adjustment and dynamic error compensation of the amplifier error. The reference circuit provides a stable reference voltage for the ADC analog-to-digital converter module, the DAC digital-to-analog converter module, and the control algorithm. The digital core control module is used for the timing control of the coarse-scale error adjustment control, fine-scale error adjustment, dynamic compensation value calculation and switch switching modules; The low-noise amplifier uses a discrete parallel JFET pair structure as the input stage of the amplifier module, including: JFET field-effect transistors Q1, Q2, Q9, and Q10. JFET field-effect transistors Q1 and Q9 are connected in parallel. The drains of JFET field-effect transistors Q1 and Q9 are connected to the emitter of transistor Q7. The collector of transistor Q7 is connected to the collector of transistor Q5. The emitter of transistor Q5 is connected to resistor R5 and then to the positive power supply. JFET field-effect transistors Q2 and Q10 are connected in parallel. The drains of JFET field-effect transistors Q2 and Q10 are connected to the emitter of transistor Q6. The collector of transistor Q6 is connected to the collector of transistor Q4. The emitter of transistor Q4 is connected to resistor R4 and then to the positive power supply. The sources of JFETs Q1, Q2, Q9, and Q10 are connected to the drain of JFET Q8. The gate of JFET Q8 is connected to the output of amplifier U1. The non-inverting input of amplifier U1 is connected to the negative power supply through diode D1. The inverting input of amplifier U1 is connected to the source of JFET Q8 and then connected to resistor R3 before being connected to the negative power supply. The base of transistor Q5 is connected to the emitter of transistor Q3 and the base of transistor Q4. The collector of transistor Q3 is connected to the base of transistor Q7. The base of transistor Q7 is connected to the base of transistor Q6. The collector of transistor Q4 is connected to the non-inverting input of amplifier U2 and the base of transistor Q3. The inverting input of amplifier U2 is connected to the collector of transistor Q7. The output of amplifier U2 is grounded through resistors R6 and R8. Resistors R6 and R8 are connected to the gates of JFET field-effect transistors Q2 and Q10.

2. The low noise DC amplifier module with static and dynamic error adjustment of claim 1, wherein, The current mirror proportional adjustment module replaces resistor R4 and includes multiple parallel resistors with individual switches. By connecting them with different resistance values, it adjusts the current in the differential branch and performs coarse-scale adjustment of the inherent error of the low-noise DC amplifier module.

3. The low noise DC amplifier module with static and dynamic error adjustment of claim 2, wherein, During coarse-scale adjustment, the switch switching module switches the low-noise amplifier to the internal ground signal, the current mirror proportional adjustment module connects different resistor combinations according to different control words, the ADC analog-to-digital conversion module collects the output voltage, the digital core control module records the voltage value of the control word and compares the absolute values. The control word with the smaller absolute value is finally retained. At this time, the inherent error is the minimum error after coarse-scale adjustment.

4. The low noise DC amplifier module with static and dynamic error adjustment of claim 1, wherein, After coarse-scale adjustment, the inherent error after coarse-scale adjustment is optimized by fine-scale using the ADC analog-to-digital converter module and the DAC digital-to-analog converter module. The switching module grounds the input of the low-noise amplifier, and the ADC analog-to-digital converter module collects the output voltage of the low-noise amplifier as the inherent error to be fine-scale adjusted. The collected inherent error is sent to the digital core control module. The digital core control module encodes the data from the ADC analog-to-digital converter module and sends it to the DAC digital-to-analog converter module. The DAC digital-to-analog converter module outputs a compensation signal and connects it to the output of the amplifier module. The DAC digital-to-analog converter module is used as a negative feedback path, and the output compensation value of the DAC analog-to-digital converter module at this time is taken as the true value.

5. The low noise DC amplifier module with static and dynamic error adjustment of claim 4, wherein, The switching circuit adjusts and controls the timing to perform fixed-cycle measurements on external and internal ground signals.

6. The low noise DC amplifier module with static and dynamic error adjustment of claim 5, wherein, After the fine-scale adjustment is completed, the digital core control module sends the control timing command to the switch switching module. The switch switching module then connects the external measurement signal and the internal ground signal according to the timing command sent by the digital core control module. When the switch switching module receives the internal ground signal, the digital core control module calculates the difference between the measured data of the ADC analog-to-digital converter module and the true value, converts the difference into a compensation value and transmits it to the DAC digital-to-analog converter module. The DAC digital-to-analog converter module receives the compensation value and adjusts it based on the original true value. When an external measurement signal is connected to the switching module, the DAC analog-to-digital converter module outputs the adjusted true value as a compensation value to the output of the amplifier module.

7. A method of operating a low noise DC amplifier module with static and dynamic error adjustment according to any one of claims 1-6, characterized in that, The steps include the following: Step 1: Switch the low-noise amplifier to the internal ground signal using the switch switching module, adjust the resistor array of the current mirror proportional adjustment module to perform coarse-scale adjustment of the inherent error, record the voltage value of the control word through the digital core control module and compare the absolute values. The control word with the smaller absolute value is finally retained. At this time, the inherent error is the minimum error after coarse-scale adjustment. Step 2: After coarse scale error adjustment is completed, the inherent error after coarse scale adjustment is adjusted using the ADC analog-to-digital converter module and the DAC digital-to-analog converter module. The switching module grounds the input of the low-noise amplifier. The ADC analog-to-digital converter module collects the output voltage of the low-noise amplifier as the inherent error to be adjusted in fine scale and sends the collected inherent error to the digital core control module. The digital core control module encodes the data from the ADC analog-to-digital converter module and sends it to the DAC digital-to-analog converter module. The DAC digital-to-analog converter module outputs a compensation signal and connects it to the output of the amplifier module. The DAC digital-to-analog converter module is used as a negative feedback path, and the output compensation value of the DAC analog-to-digital converter module at this time is taken as the true value. Step 3: After the fine ruler error adjustment is completed, the digital core control module sends the control timing command to the switch adjustment switching circuit. The switch module connects the external measurement signal and the internal ground signal according to the control timing. Step 4: When the switch adjustment circuit is connected to the ground signal, and when the switch switching module is connected to the internal ground signal, the digital core control module calculates the difference between the ADC analog-to-digital converter module's measured data and the true value, converts the difference into a compensation value, and transmits it to the DAC digital-to-analog converter module. The DAC digital-to-analog converter module receives the compensation value and adjusts based on the original true value. When an external measurement signal is connected to the switching module, the DAC analog-to-digital converter module outputs the adjusted true value as a compensation value to the output of the amplifier module.

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