A PWM based readout circuit for optical sensors with adaptive frequency control

Abstract

This paper proposes a pulse-width modulation-based readout circuit for optical sensors which adopts adaptive frequency control technique to enhance input dynamic range of current sensing systems. The proposed readout circuit is designed and fabricated using a 65 nm CMOS process. The readout IC achieves 100 dB of dynamic range in current sensing system by adaptively controlling the frequency of operating clock.