A CMOS laser radar receiver for sub-ns optical pulses

A receiver channel topology for a pulsed time-of-flight (TOF) laser rangefinder is presented. The IC receiver chip realized in a 0.18 μm CMOS technology includes a transimpedance amplifier, a post amplifier and a timing comparator. Timing detection is based on leading edge detection. A multi-channel TDC is used for compensating the amplitude-dependent timing error by detecting the pulse width of the received pulse and by using this information for calibration. The receiver channel is targeted to be used with a laser diode transmitter generating sub-ns pulses. According to the simulations, the single-shot precision is < 30 ps with SNR = 10 and the total walk error 350 ps in a dynamic range of 1:100,000.