ICS9248-56

* Generates the following system clocks: - 2CPU(2.5V) up to 100MHz. - 6 PCI(3.3V) @ 33.3MHz (Includes one free running). - 1 REF clks (3.3V) at 14.318MHz. - 1 Fixed clock at 48MHz - 1 Fixed clock at 48 or 24MHz
* Skew characteristics: - CPU CPU<175ps  - PCI PCI < 500ps  - CPU(early) PCI = 1.5ns 4ns.
* Supports Spread Spectrum modulation for CPU and PCI clocks, 0.5% down spread
* Efficient Power management scheme through stop clock and power down modes.
* Uses external 14.318MHz crystal, no external load cap required for CL=18pF crystal.
* 28 pin 209mil SSOP and 173mil TSSOP

Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . ..................................  7.0 V
Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . .  GND 0.5 V to  VDD +0.5 V
Ambient Operating Temperature . . . . . . . . . . ..................... .  0°C to +70°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . . ...........  65°C to +150°C

The ICS9248-56 is the Main clock solution for Notebook designs using the Intel 440BX style chipset.  Along with an SDRAM buffer such as the ICS9179-03, it provides all necessary clock signals for such a system.

Spread spectrum may be enabled by driving pin 26, SPREAD# active (Low) at power-on. Spread spectrum typically reduces system EMI by 8dB to 10dB. This simplifies EMI qualification without resorting to board design iterations or costly shielding. The ICS9248-56 employs a proprietary closed loop design, which tightly controls the percentage of spreading over process and temperature variations.