System and method for measuring DC offset in a sensor output by modulating a signal-independent operating parameter of the sensor

摘要

A sensor circuit enables detection of DC offset in a sensor output signal. The sensor circuit includes a sensor that generates a sensor output signal corresponding to a physical signal coupled to an input of the sensor, and a modulator that generates a modulation signal, the modulator being coupled to the sensor to modulate a physical parameter of the sensor and to enable a DC offset to be separated from the sensor output signal. To enable the circuit to measure the DC offset even though the sensor output signal is inversely proportional to the output signal, the circuit includes a feedback circuit configured to generate a feedback signal. The feedback signal is coupled to the input of the sensor to enable the physical parameter of the sensor to be modulated without modulating a portion of the sensor output signal attributable to the physical signal being converted to an electrical signal by the sensor.