The 87604I is a 1:4 PCI/PCI-X Clock Generator. The 87604I has a selectable REF_IN or crystal input. The REF_IN input accepts LVCMOS or LVTTL input levels. The 87604I has a fully integrated PLL along with frequency configurable clock and feedback outputs for multiplying and regenerating clocks with "zero delay". The PLL's VCO has an operating range of 250MHz - 500MHz, allowing this device to be used in a variety of general purpose clocking applications. For PCI/PCI-X applications in particular, the VCO frequency should be set to 400MHz. This can be accomplished by supplying 33.33MHz, 25MHz, 20MHz, or 16.66MHz on the reference clock or crystal input and by selecting ÷12, ÷16, ÷20, or ÷24, respectively as the feedback divide value. The divider on the output bank can then be configured to generate 33.33MHz (÷12), 66.66MHz (÷6), 100MHz (÷4), or 133.33MHz (÷3). The 87604I is characterized to operate with its core supply at 3.3V and the bank supply at 3.3V or 2.5V. The 87604I is packaged in a small 6.1mm x 9.7mm TSSOP body, making it ideal for use in space-constrained applications.