A 16‐bit, ±10‐V Input Range SAR ADC with a 5‐V Supply Voltage and Mixed‐Signal Nonlinearity Calibration

Abstract

This paper presents a high-precision, successive approximation register (SAR) analog-to-digital converter (ADC) with resistive analog front-end for low-voltage and wide input range applications. To suppress the serious nonlinearity brought by the voltage coefficients of analog front-end without deteriorating differential nonlinearity performance, a mixed-signal calibration scheme based on piecewise-linear method with calibration digital-to-analog converter is proposed. A compensation current is designed to sink or source from the reference to keep it independent of input signal, which greatly improves the linearity performance. Fabricated in a 0.5-μm CMOS process, the proposed ADC achieves 88-dB signal-to-noise-and-distortion ratio and 103-dB spurious free dynamic range with 5-V supply voltage and 2.5-V reference voltage, and the total power consumption is 37.5 mW.