ICS94236

www.DataSheet4U.com Integrated Circuit Systems, Inc. ICS94236 Programmable System Clock Chip for AMD - K7™ processor Recommended Application: VIA KX/KT133 style chipset Output Features: 1 - Differential pair open drain CPU clocks 1 - CPU clock @ 3.3V 13 - SDRAM @ 3.3V 6 - PCI @3.3V, 1 - 48MHz, @3.3V fixed. 1 - 24/48MHz @ 3.3V 2 - REF @3.3V, 14.318MHz. Features: Programmable ouput frequency. Programmable ouput rise/fall time. Programmable PCI_F and PCICLK skew. Spread spectrum for EMI control typically by 7dB to 8dB, with programmable spread percentage. Watchdog timer technology to reset system if over-clocking causes malfunction. Uses external 14.318MHz crystal. FS pins for frequency select Pin Configuration VDDREF REF0 GND X1 X2 VDDPCI 1 FS4/PCICLK_F **FS3/PCICLK0 GND *SEL24_48#/PCICLK1 PCICLK2 PCICLK3 PCICLK4 VDDPCI BUFFER IN GND SDRAM11 SDRAM10 VDDSDR SDRAM9 SDRAM8 GND SDATA 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 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 REF1/FS2** GND CPUCLK GND CPUCLKC0 CPUCLKT0 VDDCPU PD#* SDRAM_OUT GND SDRAM0 SDRAM1 VDDSDR SDRAM2 SDRAM3 GND SDRAM4 SDRAM5 VDDSDR SDRAM6 SDRAM7 VDD48 48MHz/FS0* 24/48MHz/FS1** 48-Pin 300mil SSOP * ** 1 Internal Pull-up Resistor of 120K to VDD. Internal Pull-down Resistor of 120K to GND. Internal Pull-down Resistor of 60K to GND. Block Diagram PLL2 /2 X1 X2 XTAL OSC PLL1 Spread Spectrum 48MHz 24_48MHz Functionality FS3 0 0 0 0 0 0 ...