General Description
The ICS9148-25 is a Clock Synthesizer chip for Pentium and PentiumPro plus Cyrix CPU based Desktop/Notebook systems that will provide all necessary clock timing.
FEATUREs
• Generates system clocks for CPU, IOAPIC, SDRAM,
PCI, plus 14.318 MHz ), USB, Plus Super I/O
• Spread spectrum for CPU/SDRAM/PCI clocks default
• Supports single or dual processor systems
• Modulation of Spread Spectrum selectable as ±0.5, ±1.0,
±2.0 or none
• Supports Intel 60, 66.8MHz, Cyrix 55, 75MHz plus 83.3
and 68MHz (Turbo of 66.6) speeds.
• Synchronous clocks skew matched to 250ps window on
CPU, SDRAM and 500ps window on PCI clocks
• CPU clocks to PCI clocks skew 1-4ns (CPU early)
• MODE input pin selects optional power management
input control pins
• Two fixed outputs, 48MHz and 24 MHz
• Separate 2.5V and 3.3V supply pins
- 2.5V or 3.3V output: CPU, IOAPIC (Strength
selectable)
- 3.3V outputs: SDRAM, PCI, REF, 48/24 MHz
• No power supply sequence requirements
• 48 pin 300 mil SSOP