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