Design of a high gain time difference amplifier

In integrated circuits, time resolution is preferred over voltage resolution as it offers larger operating range. Time difference amplifiers are also useful in measurement of small phase differences. A simple but high gain Time Difference Amplifier (TDA) is presented in this paper. The TDA amplifies the width of a pulse for precise measurement of time difference. The pulse width amplification is achieved by linear charging and discharging of a capacitor with time. The proposed circuit provides a constant gain of 120 for the input pulse width in the range of 20-240ps. The TDA operates at a supply voltage of 1.2 V and consumes 48.6 μW power. The amplifier has been implemented in 180nm UMC technology using Cadence tool.