| 摘要 |
PURPOSE:To furnish a semiconductor acceleration sensor which obtains a detection signal of high S/N without causing an increase in the size of a sensing part. CONSTITUTION:Capacitors Cs1 to Cs4 are constructed of four sets of opposed electrodes, which are formed as movable electrodes on a weight of a cantilever, and capacities thereof are changed by impression of acceleration. An input signal from the capacitors Cs1 to Cs4 (electrodes) is superposed on a carrier wave from an oscillator 18 by a sensing part 19 and a differential amplifier 20. Moreover, the central frequency (fc) of a band-pass filter 21 coincides with the frequency (f) of the carrier wave and the filter passes the superposed signal. |
