A 9-channel time-to-digital converter for an imaging lidar application

An integrated 9-channel parallel time-to-digital converter circuit has been designed for a 3D imaging laser range-finding application. The measured single-shot resolution σ-value is 312 ps (4.7 cm) or better in the whole 960 ns (144 m) measurement range. With time interval averaging resolution better than 1 ps σ-value (0.15 mm) was measured in one channel without interference. The maximum measured interchannel interference is ± 20 ps (± 3 mm). The circuit was fabricated in an 0.8 µm CMOS process and it consumes 25 mA from a single 5 V supply.