General Description

The ICS9250-10 is a single chip clock for Intel Pentium II. It provides all necessary clock signals for such a system.

Spread spectrum may be enabled through I2C programming. Spread spectrum typically reduces EMI by 8dB to 10 dB. This simplifies EMI qualification without resorting to board design iterations or costly shielding. The ICS9250-10 employs a proprietary closed loop design, which tightly controls the percentage of spreading over process and temperature variations.

Features

• Generates the following system clocks:

- 3 CPU (2.5V) 66.6/100 MHz (up to 133MHz through I2C selection)

- 9 SDRAM (3.3V) up to 133MHz

- 8 PCI (3.3 V) @33.3MHz

- 2 IOAPIC (2.5V) @16.67 or 33.3MHz

- 2 Hublink clocks (3.3 V) @ 66.6 MHz

- 2 USB (3.3V) @ 48 MHz ( Non spread spectrum)

- 1 REF (3.3V) @ 14.318 MHz

• Supports spread spectrum modulation, down spread 0 to -0.5

• I2C support for power management

• Efficient power management scheme through PD#

• Uses external 14.138 MHz crystal