GENERAL DESCRIPTION

The W83194BR-B is a Clock Synthesizer for Intel Brook dale 845 chipset. W83194BR-B provides all clocks required for high-speed microprocessor and provides step-less frequency programming and 32 different frequencies of CPU, PCI, and 3V66 clocks setting. All clocks are externally selectable with smooth transitions.

The W83194BR-B provides I2C serial bus interface to program the registers to enable or disable each clock outputs and provides -0.5 and +/-0.25 centertype spread spectrum or programmable S.S.T. scale to reduce EMI.

The W83194BR-B also has watch dog timer and reset output pin to support auto-reset when systems hanging caused by improper frequency setting.

The W83194BR-B 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 1 V /ns slew rate into 30 pF loads. CPU CLOCK outputs typically provide better than 1 V /ns slew rate into 20 pF loads as maintaining 50± 5 duty cycle. The fixed frequency outputs as REF and 48 MHz provide better than 0.5V /ns slew rate.

PRODUCT FEATURES

• 3 pairs of CPU clock outputs

• 4 3V66 clock outputs

• 9 PCI synchronous clocks

• 2 48 MHz clock outputs for USB and DOT

• Skew form CPU to PCI clock 1 to 4 ns, center 2.6 ns

• Smooth frequency switch with selections from 66.6 to 200MHz

• Step-less frequency programming

• I2C 2-Wire serial interface and I2C read back

• -0.5 and +/- 0.25 center type spread spectrum

• Programmable S.S.T. scale to reduce EMI

• Programmable registers to enable/stop each output and select modes

• Watch Dog Timer and RESET# output pins

• 48-pin SSOP package