Very high-speed CMOS comparators for multi-GS/s A/D converters

Ultra high-speed comparators for data-converters operating with conversion rate of 10+ GS/s are discussed. It is shown that the use of nanometer technologies and specific architectures allow comparator speeds in the 30 ps range or below. State-of-the-art schemes of latch are critically analysed and strategies for enhancing the speed are discussed. A novel scheme, the latch with embedded preamp, increases the speed of the fast scheme by almost a factor 2.