| 摘要 |
<P>PROBLEM TO BE SOLVED: To correct fluctuations in initial capacitance with a C-V converter circuit at the first stage to enable only sensitivity signals to be taken out and achieve a high S/N ratio. <P>SOLUTION: A capacitance difference correcting circuit 22 having a level shift circuit 23, a correction capacitance circuit 24, a consistency setting circuit 25 and an adjusting circuit 26 is provided, and a correction quantity corresponding to initial capacitance fluctuations is set by having the level shift circuit 23 select a gain A and the corrected capacitance circuit 24 select correction capacitances 24a-1 to 24a-n. It is thereby enabled to cancel an offset component attributable to initial capacitance fluctuations from the output voltage of a C-V converter circuit. Therefore, it is made possible to configure a capacitance type acceleration sensor circuit that can correct fluctuations in initial capacitance with the C-V converter circuit at the first stage, take out only sensitivity signals and achieve a high S/N ratio. <P>COPYRIGHT: (C)2012,JPO&INPIT |
