A Wide Dynamic Range Analog Front-End With Reconfigurable Transimpedance Amplifier for Direct ToF LiDAR

Abstract

A wide dynamic range analog front-end (AFE) circuit is proposed for direct time-of-flight (dToF) LiDAR applications. The reconfigurable transimpedance amplifier (TIA) is proposed with the gain control scheme to significantly increase the linear dynamic range. The feedforward compensation technique is proposed to improve the stability of the TIA and extend the bandwidth. The post amplifier is presented with active feedback to further improve the entire gain and mitigate the attenuation of the bandwidth. The proposed AFE is fabricated in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.18~{\mu }\text{m}$ </tex-math></inline-formula> CMOS technology, which achieves the −3-dB bandwidth, maximum transimpedance gain, linear dynamic range, and input-referred noise current of 260 MHz, 100 dB <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\Omega }$ </tex-math></inline-formula> , 79.3 dB, and 3.3 pA/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${{\sqrt {}}}$ </tex-math></inline-formula> Hz, respectively.