W83194BR-B

Winbond Clock Generator For Intel P4 845 Series Chipset

GENERAL DESCRIPTION

The 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