The 9DB633 zero-delay buffer supports PCIe Gen3 requirements, while being backwards compatible to PCIe Gen2 and Gen1. The 9DB633 is driven by a differential SRC output pair from an IDT 932S421 or 932SQ420 or equivalent main clock generator. It attenuates jitter on the input clock and has a selectable PLL bandwidth to maximize performance in systems with or without Spread-Spectrum clocking. An SMBus interface allows control of the PLL bandwidth and bypass options, while 2 clock request (OE#) pins make the 9DB633 suitable for Express Card applications.