A 5 MSps 13.25μW 8-bit SAR ADC with single-ended or differential input

An ultra-low energy analog-to-digital converter (ADC) able to process single-ended and differential signals, with a flexible wide-range common-mode voltage is presented. This ability has been made possible through a novel track-and-hold (TH) circuitry, which provides a differential output with a fixed common mode voltage for the ADC, and relies on switched-capacitors technique for operation. The ADC is designed in a 90 nm technology and simulated for both single-ended and differential inputs. The ADC consumes 13.25μW from a 1 V source, while providing 6.86 and 7.95 effective bits, when acquiring single-ended and differential signals, respectively. The proposed technique contributes to improve power consumption and compactness, eliminating the requirements of a power-hungry amplifier and external components.