An averaging mode time-to-amplitude converter with picosecond resolution

A time-to-amplitude converter (TAC) meant to be employed in pulsed time-of-flight (TOF) laser rangefinding and capable of operating at a very high pulse repetition rate (PRR) is described. It is based on a precise time interval between the emitted light pulses and measures the phase difference of the logic-level pulse trains formed by timing pulses derived from the transmitted and received light pulses. The fast part of the TAC is constructed by means of ECL 100 K circuits. Test results indicate that the TAC is well suited for fast, millimeter-level resolution applications, and a full width at half maximum (FWHM) resolution of 1.0 ps is achieved with a 5-MHz pulse repetition rate and 0.1-Hz-10-kHz measurement bandwidth.<
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