CLOCK SYNTH 4-PLL VCXO PROG 949
The CDCE949 and CDCEL949 are modular PLLbased low cost, high-performance, programmable clock synthesizers, multipliers and dividers. They generate up to 9 output clocks from a single input frequency. Each output can be programmed insystem for any clock frequency up to 230 MHz, using up to four independent configurable PLLs. The CDCEx949 has separate output supply pins, VDDOUT, 1.8 V for the CDCEL949, and 2.5 V to 3.3 V for CDCE949. The input accepts an external crystal or LVCMOS clock signal. If an external crystal is used, an on-chip load capacitor is adequate for most applications. The value of the load capacitor is programmable from 0 to 20 pF. Additionally, an on-chip VCXO is selectable, allowing synchronization of the output frequency to an external control signal, that is, a PWM signal.