An in-phase / quadrature (l / Q)
clock generator (400) is described. The l / Q
clock generated includes a poly-
phase filter (420) configured to generate a four-phase quadrature
clock signal (422) in response to a two-phase quadrature
clock signal (406) generated in response to a single-ended input
clock signal (402). The l / Q clock generated also includes a phase interpolator (460) configured to generate an output four-phase quadrature
clock signal (462) from the four-phase quadrature clock
signal. The l / Q clock generated further includes a poly-
phase filter tune circuit (430) coupled to an output of the phase interpolator (460). The poly-
phase filter tune circuit (430) is configured to generate a control
voltage (432) for the poly-phase filter to tune the four-phase quadrature clock
signal from the poly-phase filter.