A micropower front-end interface for differential-capacitive sensor systems

Abstract—This papers presents a front-end circuit for interfacing to differential capacitive sensors, including certain microelectromechanical systems (MEMS). The system combines a selfresetting, biphasic integrator with a difference timer, producing a word parallel output representing the differential capacitance. The measurable capacitance range is tunable by means of an input current bias and system clock frequency. For an input bias of 10nA and system clock of 128KHz, the measurable capacitance range is +/-5pF (to 8 bit resolution) consuming below 26μW total system power.

• Type: Conference
• Year: 2008
• Where: ISCAS
• Authors: Timothy G. Constandinou, Julius Georgiou, Chris Toumazou
• Keywords: Certain Microelectromechanical Systems, Hardware, Input Current Bias, ISCAS 2008, Measurable Capacitance Range