The 672-01/02 are zero delay buffers that generate four output clocks whose phases are spaced at 90° intervals. Based on IDT's proprietary low jitter Phase-Locked Loop (PLL) techniques, each device provides five low-skew outputs, with clock rates up to 84 MHz for the 672-01 and up to 135 MHz for the 672-02. By providing outputs delayed one quarter clock cycle, the device is useful for systems requiring early or late clocks. The 672-01/02 include multiplier selections of x0.5, x1, x2, x3, x4, x5, or x6. They also offer a mode to power-down all internal circuitry and tri-state the outputs. In normal operation, output clock FBCLK is tied to the FBIN pin. IDT manufactures the largest variety of clock generators and buffers, and is the largest clock supplier in the world.