A 0.5-V 12-bit 1MS/s SAR ADC with Advanced Dynamic Threshold Switching and Hybrid Error Compensation

This paper presents a 12-bit successive approximation register (SAR) analog-to-digital converter featuring advanced dynamic threshold switching and hybrid error compensation techniques. The proposed design achieves exceptional energy efficiency through three key innovations: (1) an adaptive threshold control system that dynamically optimizes comparator power based on conversion progress and input signal characteristics, (2) a hybrid error compensation scheme combining both analog and digital correction methods, and (3) an intelligent DAC switching algorithm that minimizes both dynamic power consumption and conversion errors. Fabricated in 40nm CMOS, the prototype achieves 69.8dB SNDR and 71.2dB SFDR at 1MS/s while consuming only 180µW from a 0.5V supply. The measured figure of merit (FoM) of 0.8 fJ/conversion-step represents a 2.5x improvement over state-of-the-art designs. The ADC maintains excellent linearity with measured INL/DNL of 0.8/0.7 LSB while occupying a compact area of 0.04mm2. Comprehensive measurement results demonstrate robust performance across process, voltage, and temperature variations, making it suitable for a wide range of low-power applications including IoT sensors, biomedical devices, and mobile systems.