A Wideband Low-Noise Linear LiDAR Analog Front-End Achieving 1.6-GHz Bandwidth, 2.7-pA/Hz^0.5 Input-Referred Noise, and 103-dB Transimpedance Gain

This letter presents a low-noise wideband analog front-end (AFE) circuit for long-range linear LiDAR. The nMOS feedforward transimpedance amplifier with inner feedback resistor (NFFR-TIA) is proposed to extend the bandwidth to around 400 MHz and reduce the input referred noise (IRN) concurrently with high-transimpedance gain and improved stability. Two stage continuous-time linear feedback circuits are introduced to further boost the bandwidth to over-1 GHz with flatten in-band AC response and negligible extra noise. Fabricated in a 40-nm CMOS process, our AFE achieves an average IRN of 2.7 pA/Hz( 0.5), 1.6-GHz bandwidth, 103-dB Omega transimpedance gain, and 10-mW power consumption.