Capacitance type physical quantity detector

A capacitance type physical quantity detector comprising:

• a sensor unit of which the capacitance varies depending upon a change in the physical quantity;
• and
• a C-V converter unit of the switched capacitor constitution which converts a change in the capacitance of said sensor unit into a voltage;
• wherein
• said C-V converter unit includes an operational amplifier, a feedback capacitor provided between an input terminal and an output terminal of said operational amplifier, and switching means connected in parallel with said feedback capacitor;
• and
• said capacitance type physical quantity detector further includes a reference voltage-generating circuit for applying a reference voltage to the non-inverted input terminal of said operational amplifier, and a drive voltage-generating circuit for applying a drive voltage to said sensor unit;
• wherein
• at least any one of the feedback capacitance of said feedback capacitor, the reference voltage formed by said reference voltage-generating circuit or the drive voltage formed by said drive voltage-generating circuit so varies depending upon the temperature as to correct the temperature characteristics of said sensor unit.