A continuous-time capacitance to voltage converter for microcapacitive pressure sensors

Abstract

This paper reports a continuous-time capacitance to voltage converter (CVC), based on the charge integration circuit, for capacitive pressure sensor applications. Unlike conventional charge integrators which need a large feedback resistor for biasing, the proposed method uses low duty cycle periodic reset to establish a robust dc bias at the sensing electrode. The CVC has the merits of low noise, linear transfer characteristics and low susceptibility to system offset. A CVC has been designed with standard 0.35νm CMOS technology. For a 3.3-V supply, it achieves 1mW power consumption, 0∼0.8pF detection range and 0.06% resolution. © 2006 IOP Publishing Ltd.