NOISE REDUCTION METHOD WITH CHOPPING FOR A MERGED MEMS ACCELEROMETER SENSOR

摘要

PURPOSE: A noise reduction method with chopping for a merged micro-electro-mechanical systems (MEMS) accelerometer sensor is provided to improve the reduction of 1/f noise in an MEMS accelerometer analog front end sensing circuit. CONSTITUTION: The output of an MEMS accelerometer sensing circuit is sensed to generate a differential sensor output signal (405). The output of an MEMS sensor is applied to a differential chopping circuit path (410). The polarity of the differential chopping circuit path is inverted at timed intervals. The chopped MEMS sensor output signal is sampled with a differential sigma-delta analog to digital converter (ADC) circuit to generate a digital signal representing a change in the capacitance of the MEMS sensor (415). [Reference numerals] (405) Output of an MEMS sensor is sensed to generate a differential sensor output signal; (410) Output of an MEMS sensor is applied to a differential chopping circuit path; (415) Chopped MEMS sensor output signal is sampled with a differential sigma-delta ADC circuit to generate a digital signal representing a change in the capacitance of the MEMS sensor