Programmable Clock Generators Offer Three Independent PLLs
Exhibiting frequency stabilities from ±25 ppm to ±50 ppm, SiTime’s SiT9103 and SiT9104 MEMS-based programmable clock generators present 3 independent PLLs that can offer 3 unrelated clock frequencies. The SiT9103 provides 3 differential clock outputs that can operate at up to 800 MHz in servers, routers, RAID controllers, fiber channel, PCI-Express, Gigabit Ethernet, and optical networking equipment. The SiT9104 integrates 6 single-ended clock outputs, 2 from each PLL, performing at up to 220 MHz in digital and flat-panel televisions, DVD recorders, set-top boxes, and printers. Each PLL and associated pair of clock outputs can be driven by independent voltage supplies (1.8 V, 2.5 V, 2.8 V or 3.3 V), and each output pair on the differential output SiT9103 can be configured to LVPECL, LVDS, or CML. The 7-mm × 5-mm 22-pin QFN-packaged components include an rms phase jitter of <1 ps and an integrated MEMS resonator.