Flash ADCs for multichannel integrated systems in submicron technology

Multichannel readout systems for pixel or strip detectors often need a pulse amplitude measurement. For this purpose different kind of ADCs are used. For many applications the resolution of 4-6 bits is sufficient and the most important limitations are the circuit area, power consumption and fast signal processing. Such applications favor simplicity in choice of the architecture. This paper focuses solely on the flash ADCs with limited resolution, small area and conversion rates of few megasamples per second. The reduction of the converter´s area is beneficial in terms of speed and power consumption. However, it results in more pronounced mismatch effects, increased comparator threshold voltage variations and can lead to serious resolution degradation. The aim of this paper is to find the optimal solution for comparator offset voltage compensation in flash ADCs. This paper presents a comparison and a summary of the efficiency of different techniques, in terms of area, power consumption.