A CMOS readout circuit for silicon resonant accelerometer with 32-ppb bias stability

Abstract

This paper describes a fully-differential CMOS readout circuit for silicon micro-resonant accelerometer. Tested with a SOI resonator, the readout chip sustains the oscillation at 110 kHz with a phase noise of -36dBc@1Hz and a bias stability of 0.0035Hz or 32ppb, which can be translated to an amplitude noise of 1Å/√Hz down to 0.05Hz and stability of 0.22Å up to 100 seconds. The chip is fabricated in a 0.35-um CMOS process and draws 5mA under a 3.3-V single supply.