Analog-to-digital converter with power supply-based reference

摘要

A measurement circuit is provided for measuring the resistance of a variable resistance element biased with an external voltage supply. The measurement circuit includes an analog-to-digital converter (ADC) and a reference generator connected with the ADC. The ADC is operative to receive a reference voltage and a first voltage developed across the variable resistance element, and to generate a digital output signal indicative of a relationship between the first voltage and the reference voltage. The reference generator is operative to generate the reference voltage as a function of the external voltage supply.

主权项

1. A measurement circuit for measuring a resistance of a variable resistance element biased with an external voltage supply, the measurement circuit comprising:
an analog-to-digital converter operative to receive a reference voltage and a first voltage developed across the variable resistance element, and to generate a digital output signal indicative of a relationship between the first voltage and the reference voltage, wherein a resistance of the variable resistance element varies with temperature, wherein the digital output signal is a binary code indicative of a ratio of the first voltage developed across the variable resistance element and the reference voltage; and a reference generator coupled with the analog-to-digital converter and operative to generate the reference voltage as a function of the external voltage supply.