PI6C21200 is a high-speed, low-noise PCI-Express differential clock buffer designed to be a companion with PI6C410B clock synthesizer. The device distributes twelve copies of the differential SRC clock coming from PI6C410B. The output frequency can be ratioed to offer a derivative frequency from the input frequency. Each differential output is controlled by individual OE pin, except OUT10 and OUT11 are sharing one OE_10#_11# pin. The clock outputs are controlled by input selection of SA_0, SA_1, SA_2 via SMBus, SCLK and SDA.