873991-147

The 873991-147 is a low voltage, low skew, 3.3V LVPECL or ECL Clock Generator and a member of the family of High Performance Clock Solutions from IDT. The 873991-147 has two selectable clock inputs. The CLK, nCLK pair can accept LVPECL, LVDS, LVHSTL, SSTL and HCSL input levels and, the REF_CLK pin can accept a LVCMOS or LVTTL input levels. This device has a fully integrated PLL along with frequency configurable outputs. An external feedback input and output regenerates clocks with "zero delay". The four independent banks of outputs each have their own output dividers, which allow the device to generate a multitude of different bank frequency ratios and output-to-input frequency ratios. The output frequency range is 25MHz to 480MHz and the input frequency range is 6.25MHz to 120MHz. The PLL_EN input can be used to bypass the PLL for test and system debug purposes. In bypass mode, the input clock is routed around the PLL and into the internal output dividers. The 873991-147 also has a SYNC output which can be used for system synchronization purposes. It monitors Bank A and Bank C outputs for coincident rising edges and signals a pulse per the timing diagrams in this data sheet. This feature is used primarily in applications where Bank A and Bank C are running at different frequencies, and is particularly useful when they are running at non-integer multiples of each other.