ICS9248-101

Integrated Circuit Systems, Inc. ICS9248-101 Frequency Generator & Integrated Buffers for PENTIUM/ProTM & K6 General Description The ICS9248-101 is the single chip clock solution for Notebook designs using the 440BX or the VIA Apollo Pro 133 style chipset. It provides all necessary clock signals for such a system. Spread spectrum may be enabled through I2C programming. Spread spectrum typically reduces system EMI by 8dB to 10dB. This simplifies EMI qualification without resorting to board design iterations or costly shielding. The ICS9248-101 employs a proprietary closed loop design, which tightly controls the percentage of spreading over process and temperature variations. • • Features • • • • Up to 137MHz frequency support Spread Spectrum for EMI control Serial I2C interface for Power Management, Frequency Select, Spread Spectrum. Provides the following system clocks - 4-CPUs @ 2.5/3.3V, up to 137MHz. (including CPUCLK_F) - 9-SDRAMs @3.3V, up to 137MHz (including SDRAM_F) - 8-PCI @3.3V, CPU/2 or CPU/3 (including 1 free running PCICLK_F) - 1-24/48MHz @3.3V - 1-48MHz @3.3V fixed - 2-REF @3.3V, 14.318MHz. Efficient Power management scheme through PCI and STOP CLOCKS Spread Spectrum ± .25%, & 0 to -0.5% down spread Block Diagram Pin Configuration VDDREF REF0 GNDREF X1 X2 VDDPCI *CPU2.5_3.3#/PCICLK_F *FS3/PCICLK0 GNDPCI *SEL24_48#/PCICLK1 PCICLK2 PCICLK3 PCICLK4 VDDPCI BUFFER IN GNDPCI PCICLK5 PCICLK6 VDDCOR PCI_STOP# *PD# GND48 SDATA 2 I C SCLK 1 2 3 4 5 6 7 8 9 10 11 12 13...