Method of reading an oxygen sensor input

An adjustment circuit for reading a measurement output of an automotive oxygen sensor, the adjustment circuit comprising:

• a biasing stage connected to a sensor return of the oxygen sensor, the biasing stage applying a predetermined bias voltage to the return sensor;
• an input stage connected to an output of the sensor for retrieving the measurement output from the sensor;
• and
• an A/D conversion system connected to the input stage and biasing stage for adjusting the measurement output based on the bias voltage, the A/D conversion system including:
• a differential module for generating an adjusted output based on the bias voltage and the measurement output;
• an absolute value module for generating an absolute value of the adjusted output;
• and
• an A/D converter for generating a digital value based on the absolute value, the digital value corresponding to a detected oxygen level;
• and
• wherein A/D conversion system is further connected to the biasing stage for retrieving a sensor return output from the sensor, the sensor return output defining an actual bias voltage applied to the sensor return, the differential module calculating a difference between the sensor return output and the measurement output.

An adjustment circuit for reading a measurement output of an automotive oxygen sensor, the adjustment circuit comprising:

• a biasing stage connected to a sensor return of the oxygen sensor, the biasing stage applying a predetermined bias voltage to the return sensor;
• an input stage connected to an output of the sensor for retrieving the measurement output from the sensor;
• and
• an A/D conversion system connected to the input stage and biasing stage for adjusting the measurement output based on the bias voltage, wherein the sensor has a corresponding sensor voltage range, the predetermined bias voltage shifting the sensor voltage range to a desired range, the desired range representing positive voltages and the A/D conversion system has a corresponding converter voltage range, the converter voltage range including the desired range.