Clock generator and methods using closed loop duty cycle correction

Abstract

Closed-loop duty-cycle correctors (DCCs), clock generators, memory devices, systems, and methods for generating an output clock signal having a particular duty cycle are provided, such as clock generators configured to generate an output clock signal synchronized with a received input clock signal having a predetermined duty cycle. Embodiments of clock generators include closed-loop duty cycle correctors that receive an already-controlled and corrected output signal. For example, DLL control circuitry and DCC control circuitry may each adjust a delay of a variable delay line. The DLL control circuitry adjusts the delay such that an output clock signal is synchronized with an input clock signal. The DCC control circuitry detects a duty cycle error in the output clock signal and adjusts the delay of the variable delay line to achieve a duty cycle corrected output signal. By detecting the duty cycle error in the output signal, the clock generator may achieve improved performance that can correct accumulated duty cycle error and correct for duty cycle error introduced by the duty cycle corrector itself in some embodiments.