A 16-bit sigma–delta modulator applied in micro-machined inertial sensors

A fourth-order low-distortion low-pass sigma–delta (∑⊿/ modulator is presented for micro-machined inertial sensors. The proposed single-loop single-bit feedback modulator is optimized with a feed-forward path to decrease the nonlinearities and power consumption. The IC is implemented in a standard 0.6 m CMOS technology and operates at a sampling frequency of 3.846 MHz. The chip area is 2.12 mm2 with 23 pads. The experimental results indicate a signal-to-noise ratio (SNR) of 100 dB and dynamic range (DR) of 103 dB at an oversampling rate (OSR) of 128 with the input signal amplitude of –3.88 dBFS at 9.8 kHz; the power consumption is 15 mW at a 5 V supply.