Apparatus and method for multi-phase clock calibration in high-speed data communication systems

Abstract

An apparatus for multiphase clock calibration for a transmitter in data communication systems includes a phase interpolator (PI) configured to receive a clock signal and generate multiphase clock signals with adjustable duty cycles and in-phase quadrature control. The apparatus may include a pattern generator coupled to the PI and configured to generate a pattern output based on a data signal sampled by the multiphase clock signals. The apparatus also includes a delay-adjust module coupled to the PI and configured to measure timing differences between the edges of a reference clock and the pattern output with adjustable delays. A phase detector is coupled to the pattern generator and configured to detect a phase error between the pattern output and the reference clock. A calibration controller is configured to provide controls to the PI and the delay-adjust module for adjusting delays to the reference clock and the pattern output to calibrate the multiphase clock signals.