An Analog SiPM Based Receiver With On-Chip Wideband Amplifier Module for Direct ToF LiDAR Applications

An analog silicon photomultiplier (SiPM) based receiver with wideband transimpedance amplifier (TIA) is proposed for direct ToF LiDAR applications. The analog SiPM comprises a 16 x 32 single photon avalanche diodes (SPADs) array with a 25% fill factor. A fully differential pixel readout circuit is proposed within the pixel cell to facilitate the monolithic integration with the subsequent TIA and reduce the output capacitance of the analog SiPM. The TIA with the multipath feedforward compensation technique is proposed to improse the stability and achieve a wider -3-dB bandwidth. The adder array is used in this design to output the intensity information for the walk error compensation and the target identification. The proposed receiver, which is fabricated in 0.18 mu m HV-CMOS technology, achieves a -3-dB bandwidth of 420 MHz. A maximum detection range of 65 m is obtained with 20 W laser peak power, 1.8 degrees x 1.8 degrees field of view, and 40 mm aperture. A ranging accuracy of +/- 0.4 cm and precision of 4.5 cm are attained under a condition of 5 klux ambient light based on 1000 measurement results.