are widely used in various applications, such as photoplethysmography (PPG) recording by biomedical sensors and molecular-concentration detection by electrochemical sensors. They usually require a low noise level down to pA to monitor small signal variations and a wide input range over µA to avoid saturation caused by large input fluctuations. The low-noise-level and wide-input-range requirements typically result in a dynamic range (DR) greater than 120dB. Prior high-DR current measurement front-ends either operate in the time domain using a capacitive-feedback TIA to integrate the input current and then digitize the output voltage via a digital counter
Su-Hao Wu*, Yun-Shiang Shu*, Albert Yen-Chih Chiou,
Wei-Hsiang Huang, Zhi-Xin Chen, Hung-Yi Hsieh MediaTek, Hsinchu, Taiwan *Equally-Credited Authors (ECAs) High-precision current-measurement front-ends