A 0.13μm-CMOS 90μW 51dB-SNR continuous-time accelerometer front-end with 10b SAR-ADC

A low-power front-end for a capacitive MEMS accelerometer sensor is presented. The read-out front-end includes the analog preamplifier (to sense the signal coming from the MEMS) and a Successive-Approximation A/D Converter. The off-chip MEMS is a capacitive accelerometer. Constant-charge Capacitance-to-Voltage conversion has been used with a programmable-gain (to accommodate different MEMS sensor sensitivity) Continuous-Time Preamplifier to reduce power consumption and circuit complexity. A very high- impedance MOS transistor is used for MEMS biasing, thus providing a very low frequency (