A high-sensitivity integrated-circuit capacitive pressure transducer

A high-sensitivity capacitive pressure transducer with active processing circuit on the chip has been demonstrated and evaluated. The transducer configuration has been optimized by computer-aided design to achieve highest sensitivity for a given maximum dimension. The measured sensitivity of the devices is in the range of 50-150 µV/ V . mmHg, which is approximately one order of magnitude higher than the sensitivity of the piezoresistive pressure transducer of comparable size. Theoretical analysis also shows that a sensitivity on the order of 1000 µV/V . mmHg is also possible using the capacitive approach if the dimension of the device can be enlarged and the full scale pressure range is lowered. Other characteristics of the devices have been investigated and are presented.