A 6-bit SAR ADC in TFT Flexible-Substrate

Flexible, low-cost wearable electronics call for fully flexible sensing systems, but integrating conventional silicon ADCs undermines cost and form-factor benefits. In this work a successive approximation register (SAR) ADC in thin-film transistor (TFT) is proposed and entirely implemented on a flexible substrate. The SAR-ADC, operating at 20 kHz and powered at 3 V, features a fully differential architecture with a 6-bit capacitive DAC and a single comparator to enhance robustness against charge injection from switches and to minimize area. Circuit-level simulations demonstrate excellent linearity (INL/DNL within ±0.5LSB) alongside low power consumption (0.67 mW, outperforming prior flexible implementations in resolution (ENOB= 5.83 bits) and energy efficiency. The ADC's architecture, design optimizations, and detailed simulation results are presented, confirming its viability as a key enabler for next-generation flexible body-sensing electronics.