A low-noise CMOS interface circuit for closed-loop accelerometer

In this paper, design and characterization of a 18 V switched-capacitor CMOS interface circuit for the closed-loop operation of a capacitive accelerometer is presented. The pendulous silicon accelerometer operates in atmosphere pressure and is designed for non-peaking (low-Q) response with a sensitivity of 0.5 pF/g without vacuum packaging. Test results shows that a full scale acceleration of plusmn15 g and a signal bandwidth of 300 Hz is achieved. The complete module operates from a single 18 V supply and has a measured sensitivity of 420 mV/g with a noise of floor of 10 mug/radic(Hz) in closed-loop. The chip is fabricated in the 2 mum two-metal and two-poly n-well CMOS process with an area of 15.2 mm
²
.