An analog-implemented time-difference amplifier applied for coarse-fine time-to-digital converters is presented in this paper. Implemented in 0.18-μm CMOS process, a time difference within 225 ps can be amplified 80× linearly under maximum frequency of 25 MHz. Measured maximum gain error is 4.1%. Measured output rms jitter is 84.5 ps under gain of 80×. The time amplifier consumes 1.7 mW under supply voltage of 1.8 V.
IEEE Transactions on Very Large Scale Integration Systems 23(8), pp. 1528-1533