The 853S057I is a 4:1 Differential-to-3.3V or 2.5V LVPECL/ECL Clock/Data Multiplexer which can operate up to 3GHz and is a member of the HiPerClockS ™ family of High Performance Clock Solutions from IDT. The 853S057I has 4 differential selectable clock input pairs. The CLK/nCLK input pairs can accept LVPECL, LVDS, CML or SSTL levels. The fully differential architecture and low propagation delay make it ideal for use in clock distribution circuits. The multiplexer select control inputs have ECL/LVPECL interface levels. The select pins have internal pulldown resistors.