| A CMOS integrated interfacing circuit for use in capacitive sensors has been fabricated and tested. The unique features of this circuit are: (1) The sensitivity and null point of the output voltage can be programmed independently by two controlled voltage sources. (2) The insensitivity of the circuit to large fixed stray capacitance, making it useful in silicon to silicon capacitive transducers and the two chips module approach of sensor packaging. (3) A high output level, with a sensitivity of 4.6 V/pF is obtained from a dual in-line package.; The principle, operation and applications of this circuit are presented in this thesis. The applications such as pressure transducer, accelerometer, angle sensors and flow meter are given. |
