32.4 A 1V-Supply $1.85\mathrm{V}_{\text{PP}}$ -Input-Range 1kHz-BW 181.9dB-FOMDR179.4dB-FOMSNDR 2^nd-Order Noise-Shaping SAR-ADC with Enhanced Input Impedance in 0.18μm CMOS

Wearable devices rely on accurately read bio-potentials such as ECG, EEG, EMG, and EOG (ExG) to track health. Specifications-wise, such a system requires an input-referred-noise (IRN) $< 5\mu\mathrm{V}_{\text{rms}}$ , input impedance $(\mathrm{Z}_{\text{IN}}) > 10\mathrm{M}\Omega$ and BW $\sim$ 1kHz to readout ExG signals accurately [1]. In addition, a linear-input-range (IR) $> 1\mathrm{V}_{\text{pp}}$ is desirable to avoid saturation when motion/stimulation artifacts are present. Furthermore, the above has to be achieved energy-efficiently $(\text{FOM}_{\text{SNDR}} > 175\text{dB})$ and at power envelopes $< 10\mu\mathrm{W}$ to reduce battery recharge-cycles.