W83194BR-645

The W83194BR-645 is a Clock Synthesizer for SiS645/650 chipset. W83194BR-645 provides all clocks required for high-speed Intel Pentium 4, and also provides 32 different frequencies of CPU clocks frequency setting. All clocks are externally selectable with smooth transitions. The W83194BR- 645 makes SDRAM in synchronous or asynchronous frequency with CPU clocks.

The W83194BR-645 provides step-less frequency programming by controlling the VCO freq. and the programmable AGP, PCI clock output divisor ratio. A watchdog timer is quipped and when time out, register9 bit5 will be set to 1 for warning. Spread spectrum built in at ±0.5% or ±0.25% to reduce EMI. Programmable stopping individual clock outputs and frequency selection through I²C interface.

The W83194BR-645 accepts a 14.318 MHz reference crystal as its input and runs on a 3.3V supply. High drive PCI CLOCK outputs typically provide greater than 1V /nS slew rate into 30 pF loads. The fixed frequency outputs as REF, 24 MHz, and 48 MHz provide better than 0.5V /nS slew rate.