Patent ID: 6828802
Filing Date: 2004-12-07
Classification: G01L

Abstract:
A pressure measurement device for sensing pressure in an industrial process, comprising:a digital clock circuit that provides excitation clock pulses, and control output pulses that are out of phase with the excitation clock pulses; a first integrator including a first switch controlled by the control output pulses, a first amplifier, and a capacitive pressure transducer fluidly couplable to the industrial process and having a first pressure sensing capacitance electrically coupled in an amplifier feedback path between a first amplifier output and a first amplifier input, the first switch connecting across the first pressure sensing capacitance; the amplifier providing an output representative of the pressure, and the control output pulses resetting the first amplifier output; a first reference capacitance that is insensitive to the pressure and that couples the excitation clock pulses to the first amplifier input; and a summing circuit receiving the first amplifier output that is reset by the control output pulses and a first reference potential; the summing circuit providing a summing circuit output representing the pressure.