Abstract A comparison of NMOS and PMOS input driving dynamic comparator is carried out in 45nm technology. NMOS driving dynamic comparator shows lesser delay and consumes less power as compared to PMOS driving comparator. The advantage of the later is the noise immunity at higher frequencies. The normalized energy-noise-delay-product (ENDP) for NMOS dynamic comparator and PMOS dynamic comparator is 2.08 and 4.48, respectively.