An Analog-Front-End with Ultra Low-Power in Optical Sensor for FMCW LiDAR System

초록

This paper presents an analog front-end (AFE) designed for an optical receiver in a frequency-modulated continuous wave (FMCW) light detection and ranging (LiDAR) system. To achieve high linearity and low noise, a shunt feedback transimpedance amplifier (SF-TIA) is proposed with an input DC current cancellation (IDCC) circuit, followed by a postamplifier (PA) and a 50 Ω output buffer. The measurement results, implemented in a 28-nm CMOS process with a 1 V supply, demonstrate an AFE gain of approximately 85.5 dBΩ, a bandwidth of 130 MHz, an acceptable input DC current range of 0 μA to 100 A, an input-referred noise of 4.04 pA/√ Hz, a power consumption of 343 μW, and chip size of 0.61 × 0.53 mm2 with I/O pads. Consequently, the overall operation of the optical sensor combined with the transmitter is evaluated to verify system-level performance with a 0.75% accuracy error. © 2025 IEEE.

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