A Pulse Width-Controlled CMOS Laser Diode Pulser and a Time-Gated Time-Resolved SPAD Array Transceiver Chip for Diffuse Optics

A pulse width-controlled CMOS pulser for a semiconductor laser diode (LD) and a time-gated time-resolved 8x4 single-photon avalanche diode array with a time-to-digital converter (TDC) were designed on a single integrated circuit and simulated by using a 150 nm technology. The pulse width of the driving current can be adjusted from 0.5 ns to 2.5 ns with a resolution of 100 ps. The start time of the time-gating can be adjusted over a dynamic range of 4.8 ns with a resolution of 100 ps and, furthermore, a 121 ps time-gating can be achieved. The returning photons are detected by the TDC with a resolution of 50 ps and stored to the 128 14-bit counters for merging to the distribution time-of-flight histogram. The average power consumption of the whole system was 377 mW at a repetition rate of 10 MHz.