A 83dB SNDR low power readout ASIC for piezoresistive nanogauge based gyroscopes

We report a 3-channel ASIC for M&NEMS coriolis vibratory gyroscopes. Key element of each analog frontend (AFE) channel is a closed-loop interface amplifier with current reuse for the biasing of the piezoresistive nanogauge sensor detection. The outputs of the 3-channels are multiplexed to a single band-pass sigma delta modulator for on-chip analog to digital conversion. The fabricated ASIC achieves per channel a SNDR of 73dB and 83dB for a 400Hz and 50Hz bandwidth respectively. A single AFE consumes 672mW at a supply voltage of 2.4V and occupies an area of 0.3mm2.