Single-phase edge-triggered dual-rail dynamic flip-flop

Abstract

A single phase edge-triggered dual-rail dynamic flip-flop circuit for use with dynamic logic gates includes an input stage, precharge stage and buffer. The input stage is coupled to receive a data-input signal and a clock signal. During the precharge phase, the input stage provides an output signal that is the complement of the data input signal. When the data input signal is provided by a dynamic logic gate, the input stage output signal is precharged to a logic high level. During the evaluation phase, the input stage generates an output signal that either remains at a logic high level or else transitions from high-to-low. The precharge stage receives the output signal from the input stage and the clock signal. During the precharge phase, the precharge stage generates a logic high level output signal independently of the signal received from the input stage. However, the logic high level signal from the input stage turns on hard a n-channel transistor in the precharge stage, which minimizes the delay through the precharge stage during the evaluation phase. During the evaluation phase, the precharge stage outputs the complement of the output signal received from the input stage. The buffer is coupled to receive the output signal from the precharge stage. During both the precharge and evaluation phases, the buffer outputs the complement of the output signal received from the precharge stage.