Four Channel, 40 ps Resolution, Fully Integrated Time-to-Amplitude Converter for Time-Resolved Photon Counting Matteo Crotti

Abstract

Recently, a growing interest has arisen about the time- correlated single photon counti ng (TCSPC) technique, that allows the analysis of fast and weak light waveforms with a time reso- lution in the picosecond order. Since TCSPC b asically consists of the measurement of the arrival time of a photon, a high resolution and high linearity time measurement block is of the utmost im- portance; moreover, the use of multianode Photo Multiplier Tube and of single photon avalanche diode arrays led to the development of multichannel acquisition systems, where the time measurement block has to be integrated to reduceboth cost and area. We have de- signed and fabricated a four chan nel fully integrated time-to-am- plitude converter (TAC), built in 0.35 m Si-Ge technology, char- a c t e r i z e db ya ne x c e l l e n tt i m er esolution (less than 50 ps full width half maximum), low differential nonlinearity (better than 0.02 LSB peak-peak and 0.0003 LSB rms), high counting rate (16 MHz), low and constant power dissipatio n (50 mW) and low area occupation (2.58 1.28 mm ). Moreover, the very low crosstalk ( 115 dB) be- tween channels, together with low power and low area makes the converter suitable for la rge scale multi-channel acquisition chains.