W83194R-39

The W83194R-39/-39A is a Clock Synthesizer which provides all clocks required for high-speed RISC or CISC microprocessor such as Intel Pentium II. W83194R-39 provides eight different frequency of CPU and PCI clocks and W83194R-39A provides sixteen CPU/PCI frequencies which are externally selectable with smooth transitions. W83194R-39/-39A also provides 13 SDRAM clocks controlled by the none-delay buffer_in pin.

The W83194R-39/-39A accepts a 14.318 MHz reference crystal as its input and runs on a 3.3V supply. Spread spectrum built in at ¡Ó0.5% or ¡Ó0.25% to reduce EMI. Programmable stopping individual clock outputs and frequency selection through I²C interface. The device meets the Pentium power-up stabilization, which requires CPU and PCI clocks be stable within 2 ms after power-up. It is not recommend to use the dual function pin for the slots(ISA, PCI, CPU, DIMM). The add on cards may have a pull up or pull down.

High drive six PCI and thirteen SDRAM CLOCK outputs typically provide greater than 1 V /ns slew rate into 30 pF loads. Two CPU CLOCK outputs typically provide better than 1 V /ns slew rate into 20 pF loads as maintaining 50¡Ó 5% duty cycle. The fixed frequency outputs as REF, 24MHz, and 48 MHz provide better than 0.5V /ns slew rate.