A high resolution time measurement system

Abstract

A high-resolution, less than 1-ps, time measurement system (TMS) has been developed using a time-to-voltage (T/V) conversion interpolation technique. In order to accomplish the high-resolution measurement, the authors developed two specific techniques. One is the generation of an accurate interpolation pulse from the measured signal that is realized by the emitter-coupled logic (ECL)-gate-array. The other is the T/V converter which converts the pulse width to the corresponding voltage to thereby measure the pulse width. The T/V converter consists of current switches, and integrated capacitor and a buffer amplifier. The switched current charges the capacitor during the time that the interpolation pulse is on a high level. In this conversion, high-speed and accurate analog circuit design are being used, and therefore a 1-ps time resolution and a less than 10-ps linearity error are obtained. The system is composed of a wideband input amplifier, a 16-b microprocessor and a highly stabilized oscillator. The total RMS jitter using this system is less than 15-ps, and single-shot resolution is less than 1 ps. TMS has many applications, for example, time interval measurement, jitter analysis, measurement of frequency stability, etc.<>