
Integrated Circuit Systems
General Description
The ICS9169C-272 is a low-cost frequency generator designed specifically for Pentium based chip set systems. The integrated buffer minimizes skew and provides all the clocks required. A 14.318 MHz XTAL oscillator provides the reference clock to generate standard Pentium frequencies. The CPU clock makes gradual frequency transitions without violating the PLL timing of internal microprocessor clock multipliers. A raised frequency setting of 68.5MHz is available in the Turbo-mode of the 66.8MHz CPU. The ICS9169C-272 contains 12 CPU clocks, 4 PCI clocks, 1 REF at 48MHz and 1 at 24MHz.
FEATUREs
• Twelve selectable CPU clocks operate up to 83.3MHz
• Maximum CPU jitter of ± 200ps
• Six BUS clocks support sync or async bus operation
• 250ps skew window for CPU outputs, 500ps skew window for BUS outputs
• CPU clocks BUS clocks skew 1-4ns (CPU early)
• Integrated buffer outputs drive up to 30pF loads
• 3.0V - 3.7V supply range, CPU(1:6) outputs 2.5V(2.375- 2.62V) VDD option
• 32-pin SOIC/SOJ package
• Logic inputs latched at Power-On for frequency selection saving pins as Input/Output
• 48 MHz clock for USB support and 24 MHz clock for FD.