Resistance network circuit for measuring ADC

Abstract

The invention discloses a resistance network circuit for measuring an ADC, which comprises an upper arm resistance network, a lower arm resistance network, a bridge network and an SOC, and is characterized in that the upper arm resistance network comprises an upper arm left branch resistance network and an upper arm right branch resistance network, and the lower arm resistance network comprises a lower arm left branch resistance network and a lower arm right branch resistance network; the bridge network comprises a bridge left branch resistance network and a bridge right branch resistance network; the SOC is provided with an ADC channel 0 input port AIP0 and an ADC channel 0 input port AIN0, and the SOC is coupled with the jumper cap J1 and the jumper cap J2 through the AIP0 and the AIN0 respectively. Compared with a signal provided by a slide rheostat, the resistor is useful from the milliohm level to the mega level, the resistance value adjusted by the slide rheostat is not fine, and the resistance value of the resistor is stable and good in measurement effect.

Description

technical field [0001] The invention relates to the technical field of ADC measurement, in particular to a resistance network circuit for measuring ADC. Background technique [0002] At present, whether it is a general-purpose MCU, SOC or a dedicated MCU, SOC, the ADC module is indispensable, and it is particularly difficult to accurately measure weak signals with a differential input range of -vref-vref; [0003] For the circuit for measuring the ADC, the current method is to change the resistance value through the sliding rheostat to realize the adjustment of the differential signal. The current method has the following defects: [0004] First, the sliding rheostat cannot provide a weak differential signal source, and the resistance value provided by the sliding rheostat is not fine enough to accurately adjust the common-mode signal and differential signal, resulting in poor ADC measurement results; [0005] Second, when measuring weak signals, the resistance accuracy pro...

AI Technical Summary

Problems solved by technology

[0004] First, the sliding rheostat cannot provide a weak differential signal source, and the resistance value provided by the sliding rheostat is not fine enough to accurately adjust the common-mode signal and differential signal, resulting in poor ADC measurement results;

[0005] Second, when measuring weak signals, the resistance accuracy provided by the sliding rheostat is not enough. When adjusting the resistance value through the sliding rheostat, the resistance value is not stable enough, which is easy to cause signal interference, which is not conducive to the test range from -vref- ADC of vref;

[0006] Third, for different differential signals, the resistance value calculated through the bridge network may not be exactly the standard resistance value. If a single resistance network is used, there is no way to meet the precise input signal requirements. In addition, when the test item needs to be retested , frequent welding of different resistors is cumbersome to operate, and welding resistors back and forth each time is easy to introduce new weak signal errors;

[0007] Based on the current situation, the existing technology can no longer meet the needs of people at the present stage, and there is an urgent need to reform the existing technology

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