W83194BR-B

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