Patent ID: 11327099

Abstract:
Disclosed are a high-precision resistance measurement system and method combining a micro-differential method and a ratiometric method. The system includes a constant-current source, a reference resistor, a first differential amplifier, a programmable gain amplifier (PGA), an ADC, a microprocessor, a DAC and a to-be-measured resistor interface. The reference resistor and a to-be-measured resistor are connected in series between the constant-current source and ground. The voltage across the reference resistor is inputted to the first differential amplifier, and the output of the first differential amplifier is used as the reference voltage for the ADC and the DAC. The single-ended voltage to ground of the to-be-measured resistor and the output voltage of the DAC are inputted to the PGA in differential manner, and the PGA outputs the amplified difference voltage to the ADC. The output terminal of the ADC and the input terminal of the DAC are both connected to the microprocessor.