Internal clock generating circuit of semiconductor memory device and method thereof

摘要

An internal clock generating circuit and method for generating an internal clock phase-synchronized to an input clock with minimum delay and at high speed is disclosed. An internal clock generating circuit comprises a first delay control circuit for generating a first clock having the time delay of up to T/2 (where T is a cycle of an input clock) from the input clock and for generating a first variable delay control signal; and a second delay control circuit for generating a second clock in response to the first variable delay control signal, the second clock having the time delay of greater than T/2 from the input clock at an initial state and having the time delay of about T from the input clock in a phase-locked state.