Supply Voltage Of Circuits Research Articles

An integrated miniature capacitive pressure sensor

A newly designed capacitive pressure sensor which incorporates a CMOS IC on the same silicon chip has been developed. The sensor chip is 3.3 mm × 3.7 mm × 0.5 mm in size, and both the sensing capacitive element and the electronic circuit are hermetically sealed between the silicon substrate and the glass cover using a unique electrical feedthrough structure. The incorporated electronic circuit is the C-F converter whose oscillation frequency changes as a function of the sensing capacitance. By optimizing the circuit supply voltage, the thermally induced baseline (oscillation frequency at atmospheric pressure) drift can be reduced to within 3.1% F.S. between 20 °C and 50 °C. Since the oscillation frequency can be counted by the consumed current pulses, the pressure waveform can be monitored with only two external leads.

Protection against junction burnout by current limiting

Provides design curves which determine optimum resistor or inductor values for surge protection, provided that an upper bound on surge duration and circuit supply voltages are known. The resistor or inductor values are optimized in the sense that maximum theoretical energy transfers to semiconductor junctions are equated to predetermined burnout thresholds.