An Integrated 200MHz 4A Pulsed Laser Driver with DLL-Based Time Interpolator for Indirect Time-of-Flight Applications

This paper presents an integrated pulsed laser driver in 180nm BCD process for indirect time-of-flight applications. Pulses with 4A peak current at a modulation frequency up to 200MHz can be generated. Automatic optical power control (AOPC) is realized for laser eye safety protection. A DLL-based time interpolator is proposed to eliminate the mechanical moving components used during system calibration. The measured absolute accuracy of the time interpolator is +/−50ps with a resolution of 800ps and tuning range of 49. 6ns. This work effectively extends the measurement distance of the I-ToF system. The calibration efficiency is also improved with the proposed method.