MPC950

* Absolute maximum continuous ratings are those values beyond which damage to the device may occur. Exposure to these conditions or conditions beyond those indicated may adversely affect device reliability. Functional operation under absolutemaximumrated conditions is not implied.

The MPC950 is a 3.3V compatible, PLL based clock driver device targeted for high performance clock tree designs. With output frequencies of up to 180MHz and output skews of 375ps the MPC950 is ideal for the most demanding clock tree designs. The devices employ a fully differential PLL design to minimize cycletocycle and long term jitter.

This parameter is of significant importance when the clock driver is providing the reference clock for PLL's on board today's microprocessors and ASiC's. The MPC950 offers 9 low skew outputs, the outputs of MPC950 are configurable to support the clocking needs of the various high performance microprocessors.
• Fully Integrated PLL
• Oscillator or Crystal Reference Input
• Output Frequency up to 180MHz
• Outputs Disable in High Impedance
• Compatible with PowerPCE, Intel and High Performance RISC Microprocessors
• LQFP Packaging
• Output Frequency Configurable
• ±100ps Typical CycletoCycle Jitter
Two selectable feedback division ratios are available on the MPC950 to provide input reference clock flexibility. The FBSEL pin will choose between a divide by 8 or a divide by 16 of the VCO frequency to be compared with the input reference to the MPC950. The internal VCO is running at either 2x or 4x the high speed output, depending on configuration, so that the input reference will be either one half, one fourth or one eighth the high speed output.

The MPC950 provides an external test clock input for scan clock distribution or system diagnostics. In addition the REF_SEL pin allows the user to select between a crystal input to an onboard oscillator for the reference or to chose a TTL level oscillator input directly. The onboard crystal oscillator MPC950 requires no external components beyond a series resonant crystal.

The MPC950 is fully 3.3V compatible and require no external loop filter components. All inputs accept LVCMOS or LVTTL
compatible levels while the outputs provide LVCMOS levels with the capability to drive terminated 50W transmission lines. Select inputs do not have internal pullup/pulldown resistors and thus must be set externally. For series terminated 50W lines, each of the MPC950 outputs can drive two traces giving the MPC950 an effective fanout of 1:18. The device is packaged in a 7x7mm 32lead LQFP package to provide the optimum combination of board density and performance.