W83194R-81

W83194R-81 100MHZ CLOCK FOR SIS CHIPSET 1.0 GENERAL DESCRIPTION The W83194R-81 is a Clock Synthesizer for SiS chipset. W83194R-81 provides all clocks required for high-speed RISC or CISC microprocessor such as AMD,Cyrix,Intel Pentium and also provides 16 different frequencies of CPU clocks frequency setting. All clocks are externally selectable with smooth transitions. The W83194R-81 makes SDRAM in synchronous or asynchronous frequency with CPU clocks. The W83194R-81 provides I2C serial bus interface to program the registers to enable or disable each clock outputs and W83194R-81 provides the 0.25%, 0.5% center type spread spectrum to reduce EMI. The W83194R-81 accepts a 14.318 MHz reference crystal as its input and runs on a 3.3V supply. High drive PCI and SDRAM 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¡Ó 5% duty cycle. The fixed frequency outputs as REF, 24MHz, and 48 MHz provide better than 0.5V /ns slew rate. 2.0 PRODUCT FEATURES Supports Pentium™, Pentium™ Pro, AMD and Cyrix CPUs with I2C. 3 CPU clocks 13 SDRAM clocks for 3 DIMMs 6 PCI synchronous clocks. Optional single or mixed supply: (Vdd = Vddq4=Vddq3 = Vddq2b = 3.3V, Vddq2=2.5V) or (Vdd = Vddq4=Vddq3 = 3.3V, Vddq2=Vdq2b = 2.5V) Skew form CPU to PCI clock -1 to 4 ns, center 2.6 ns SDRAM frequency synchronous or asynchronous to CPU clocks Smooth frequency switch with se...