ICS9250-18

Integrated Circuit Systems, Inc. ICS9250-18 Frequency Generator & Integrated Buffers for Celeron & PII/III™ Recommended Application: BX, Appollo Pro 133 type of chip set. Output Features: 3 - CPUs @2.5V, up to 166MHz. 17 - SDRAM @ 3.3V, up to 166MHz. 7 - PCI @3.3V 2 - IOAPIC @ 2.5V 1 - 48MHz, @3.3V fixed. 1 - 24MHz @ 3.3V 2 - REF @3.3V, 14.318MHz. Features: Up to 166MHz frequency support Support power management: CPU, PCI, stop and Power down Mode form I2C programming. Spread spectrum for EMI control (± 0.25% center spread) Uses external 14.318MHz crystal Key Specifications: CPU – CPU: <175ps CPU – PCI: 1 - 4ns PCI – PCI: <500ps SDRAM - SDRAM: <250ps Pin Configuration VDDREF *FS2/REF1 *PCI_STOP#/REF0 GND X1 X2 VDDPCI *MODE/PCICLK_F *FS3/PCICLK0 GND PCICLK1 PCICLK2 PCICLK3 PCICLK4 VDDPCI PCICLK5 BUFFERIN SDRAM11 SDRAM10 VDDSDR SDRAM9 SDRAM8 GND SDRAM15 SDRAM14 GND SDATA 2 I C SCLK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 VDDLIOAPIC IOAPIC0 IOAPIC_F GND CPUCLK_F CPUCLK1 VDDLCPU CPUCLK2 GND CPU_STOP# SDRAM_F VDDSDR SDRAM0 SDRAM1 GND SDRAM2 SDRAM3 SDRAM4 SDRAM5 VDDSDR SDRAM6 SDRAM7 GND SDRAM12 SDRAM13 VDD48 24MHz/FS0* 1 48MHz/FSI* { 56-Pin SSOP Block Diagram * Internal Pull-up Resistor of 240K to 3.3V on indicated inputs ** Internal Pull-down resistor of 240K to GND on indicated inputs. 1. This output is double strength. Functio...