Patent ID: 8144041

Claim:
An electronic device comprising: a detection device; a pick up circuit for detecting, as a signal, physical information detected by the detection device; an analog-digital (AD) converter for AD converting the signal detected by the pick up circuit; a frequency variable circuit for changing a sampling frequency of the analog-digital converter; a filter for limiting a pass band of an output signal of the analog-digital converter; and an output voltage decision circuit for calculating an integral of a noise level of the output signal of the analog-digital converter after the output signal passes through the filter, wherein the electronic device performs self-diagnosis by making the frequency variable circuit change the sampling frequency of the analog-digital converter to a frequency outside of the pass band of the filter so as to change a quantization noise level of the analog-digital converter, and then by making the output voltage decision circuit determine whether the integral of the quantization noise level is within a predetermined range or not.