US Patent 7528630 High speed flip-flop

A flip-flop circuit includes a precharging circuit which precharges a first circuit node in response to a first pulse signal and an estimation circuit that receives an input signal and a second pulse signal. The estimation circuit discharges the voltage from the first node in response to the input signal on activation of the second pulse signal. The first pulse signal is synchronized to a clock signal and the second pulse signal is delayed from the first pulse signal.