ACD, a New, Very Low-Power, Compact Analogue-to-Digital Conversion Technique for Particle Tracking Detectors

A new very low power analogue-to-digital conversion technique (ACD: analogue-to-count digitizer) is proposed for application in ionizing radiation detection. The prototype circuit processed in IBM 0.25 mum CMOS technology has a 45 mum pitch compatible with the implementation of one digitizer per channel in multi-channel readout ASIC for silicon tracking detectors. The power consumption is 0.48 mW for 4 bits resolution. With a signal bandwidth of 1.2 MHz and a sampling frequency of 20 MHz, INL and DNL are below plusmn 0.3 and plusmn 0.4 LSB respectively. Factor of merit (FOM) and improvements in signal bandwidth will be discussed.