Method for measuring resistance value of conversion resistor of current-mode analog to digital converter

Abstract

The invention provides a method for measuring a resistance value of a conversion resistor of a current-mode analog to digital converter, which is used for improving the measurement and control precision of a measured physical object. The method comprises the following steps of: keeping a current signal input into the current-mode analog to digital converter constant; acquiring a first digital value AD0 which is obtained after the current signal is converted by the current-mode analog to digital converter; parallelly connecting a resistor Rj of which the precision is higher than that of the conversion resistor Rz of the current-mode analog to digital converter with the conversion resistor Rz; acquiring a second digital value AD1 which is obtained after the current signal is converted by the current-mode analog to digital converter again; and obtaining the resistance value of the conversion resistor Rz according to a formula shown in the specifications, wherein R1 is the obtained resistance value of the conversion resistor R2 and R2 is the resistance value of the resistor Rj of which the precision is higher than that of the conversion resistor Rz.

Description

technical field [0001] The invention relates to the field of current-mode analog-to-digital converters, in particular to a method for measuring the resistance value of a conversion resistor of the current-mode analog-to-digital converter. Background technique [0002] Usually, in order to realize the detection or control of the measured physical object (for example, the rotation angle detected by the rotation angle sensor), it is necessary to use the sensor to output the analog current or voltage signal reflecting the change of the measured physical object to the analog-to-digital converter, and The analog signal is converted into a digital signal that can be recognized and processed by a computer or PLC by an analog-to-digital converter. Since the current signal cannot be directly converted from analog to digital, the current signal must be converted into a voltage signal before analog to digital conversion can be performed. This requires the use of switching resistors, wh...

AI Technical Summary

Problems solved by technology

[0008] The present invention aims at the defects in the prior art that special measuring tools are needed to obtain the maximum and minimum values ​​of the actual value of the physical object under test when detecting or controlling the physical object under test, and provides a simple and easy A method for measuring the resistance value of the conversion resistance of the current-mode analog-to-digital converter in order to improve the accuracy of measuring and controlling the measured physical object

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