A Sub-ns Integrated CMOS Laser Driver With Configurable Laser Pulses for Time-of-Flight Applications

Abstract

An integrated pulsed laser driver in a 0.18-μm CMOS technology has been developed for generating configurable and stable laser diode pulses for time-of-flight applications. The duration of the output optical laser pulses can be configured from below 100 ps up to 5 ns, with 1-ps typical resolution, by a combination of a coarse and a fine delay generator. The pulse-width stability has been designed against process, supply voltage and temperature variations. This has been carried out using a system with two phase-locked loops that regulate the supply voltage of the chain of inverters, found in the driver and pre-driver improving by 2.5 times the stability compared to the case, where a fixed supply voltage is applied. Laser current can be configured up to 500 mA and output pulses are generated at a repetition rate up to 200 MHz.