Method of reading an oxygen sensor input

摘要

An adjustment circuit and method for reading a measurement output of an automotive oxygen sensor provide correction for outgassing of the sensor and inversion of the measurement output. The adjustment circuit includes a biasing stage connected to a sensor return of the oxygen sensor, where the biasing stage applies a predetermined bias voltage to the sensor return. An input stage is connected to an output of the sensor for retrieving the measurement output from the sensor. The adjustment circuit further includes an A/D conversion system connected to the input stage for adjusting the measurement output based on the bias voltage. The A/D conversion system may further be connected to the biasing stage for retrieving a sensor return output from the sensor. In such cases, a differential module calculates a difference between the sensor return output and the measurement output. The sensor return output defines an actual bias voltage applied to the sensor return.