A low offset low power CMOS dynamic comparator for analog to digital converters

In this research, a new architecture of dynamic latch comparator is presented, which is able to provide high-speed, consumes low-power and low offset voltage. The proposed comparator has been verified in a design, a 12-Bit SAR ADC(Successive Approximation Register Charge-Redistribution Analog-To-Digital Converter). The comparator consists of two stage pre-amplifier and a StrongLatch. The pre-amplifier adopts an inverter-based input pair and a pair of capacitances in output stage to reduce noise. It is shown by simulation and analysis that the offset voltage is significantly reduced compared to a conventional dynamic latched comparator. The proposed circuit is designed and simulated in 28 nm CMOS technology. The results show that, for the proposed comparator, the speed is 2.37 ns and consumes only 426.6 mu W power, at 1.8 V supply voltage and 330 MHz clock frequency. This article presents two kinds of FoM(Figure of Merit) to prove that the comparator has excellent performance.