CMOS Comparators for High-Speed and Low-Power Applications

In this paper, we present two designs for CMOS comparators: one which is targeted for high-speed applications and another for low-power applications. Additionally, we present hierarchical pipelined comparators which can be optimized for delay, area, or power consumption by using either design in different stages. Simulation results for our fastest hierarchical 64-bit comparator with a 1.2 V 100 nm process demonstrate a worst-case delay of 440 ps. To enable a fair comparison with previously reported approaches, we also simulated our designs with a 5.0 V AMIS 0.5 mum process as well. For this experiment, the fastest design has a latency of 1.33 ns, which represents a 37% speed improvement over the best previously reported approach to date (which was implemented in a 0.5 mum process).