Patent ID: 8093926

Claim:
A physical quantity detection circuit used for a physical quantity sensor that outputs a sensor signal according to a physical quantity given externally, the circuit comprising: an analog-to-digital converter circuit configured to convert the sensor signal to a digital sensor signal; a digital filter configured to attenuate a frequency component of the digital sensor signal obtained by the analog-to-digital converter circuit that is higher than a predetermined cutoff frequency; a multiplier circuit configured to multiply a digital sensor signal having passed the digital filter by a digital detection signal corresponding to a sine wave signal to detect a digital physical quantity signal corresponding to the physical quantity; an interpolation filter configured to increase the sampling frequency of a digital physical quantity signal received from the multiplier circuit; a digital-to-analog converter circuit configured to convert a digital physical quantity signal received from the interpolation filter to an analog physical quantity signal; and an analog low-pass filter configured to attenuate a frequency component of the analog physical quantity signal obtained by the digital-to-analog converter circuit that is higher than a predetermined cutoff frequency.