The ICS672-01 and ICS672-02 are zero delay buffers that generate four output clocks whose phases are spaced at 90 intervals. Based on ICS' proprietary low jitter Phase Locked Loop (PLL) techniques, each device provides five low skew outputs, with clock rates up to 84 MHz for the ICS672-01 and up to 135 MHz for the ICS672-02. By providing outputs delayed one quarter clock cycle, the device is useful for systems requiring early or late clocks.