The CY29949 is a low-voltage 200-MHz clock distribution buffer with the capability to select either a differential LVPECL or LVCMOS/LVTTL compatible input clocks. These clock sources can be used to provide for test clocks as well as the primary system clocks. All other control inputs are LVCMOS/LVTTL compatible. The 15 outputs are LVCMOS or LVTTL compatible and can drive 50 series or parallel terminated transmission lines. For series terminated transmission lines, each output can drive one or two traces giving the device an effective fanout of 1:30.