Xilinx, Inc.
Electrical circuits and methods to correct duty cycle error

Abstract:

Electrical circuits and associated methods relate to duty cycle correction having a voltage controlled delay line VCDL controlled by an analog voltage and a digital command signal to generate a VCDL.sub.out signal. In an illustrative example, the analog voltage may be generated by an analog circuit, the analog circuit may include a reference voltage, a low-pass filter, an amplifier and a loop filter. In an illustrative example, the analog circuit may be controlled by an analog command signal. The analog command signal may be programmable applied on the analog circuit to produce the analog voltage. The digital command signal may be programmable to select desired delay band in the VCDL. The analog voltage and the digital command signal may be applied to the VCDL together to obtain a desired duty cycle.