Patent ID: 7282978
Filing Date: 2007-10-16
Classification: H03K

Abstract:
1. A duty cycle correction device comprising: a mixer receiving a first clock signal and a second clock signal, and mixing phases of the first and second clock signals according to a digital control signal having logic, thereby outputting a first signal; a phase splitter receiving the first signal, and outputting a third clock signal by delaying the first signal for a predetermined period of time and a fourth clock signal by delaying and inverting the first signal for a predetermined period of time; a duty detection unit receiving the third and fourth clock signals, and detecting a difference between duty cycles of the third and fourth clock signals; a combination unit outputting a second signal, by combining an output signal of the duty detection unit and previously-stored output signals; and a shift register generating the digital control signal having the logic values corresponding to a logical level of the second signal and outputting the digital control signal to adjust a mixing ratio of the first and second clock signals, which are applied to the mixer, in response to the first and second clock signal.