DAC Output Calibration for Timing Skew and Duty-Cycle Distortion

The patent implements a feedback mechanism where the DAC output is fed back to a phase detector that compares the actual clock phases with ideal phases. The phase detector generates error signals that are used to adjust the clock phases through digital delay elements, creating a closed-loop system that continuously corrects timing skew and duty-cycle distortion, thereby maintaining timing accuracy despite using multiple clock phases for high data rates

The calibration system performs self-correction by automatically detecting its own timing errors through the phase detector and correcting them via the delay elements. The system monitors its own performance and adjusts its internal clock phases without external intervention, enabling the DAC to self-correct timing skew and duty-cycle distortion while operating at high speeds

The phase detector continuously monitors the actual clock phases and feeds back error information to adjust the phases through digital delay elements. This closed-loop feedback ensures that clock phase accuracy is maintained despite the use of multiple phases for high-speed operation, as any deviations are automatically detected and corrected

The patent changes the timing parameters of the clock phases dynamically by adjusting the delay elements in response to detected phase errors. The digital delay elements modify the phase shift amounts to correct timing skew and duty-cycle distortion, allowing the system to adapt clock phase parameters in real-time to maintain accuracy at high data rates