ICS9248-103 Datasheet | Integrated Circuit Systems

Integrated Circuit Systems, Inc. Frequency Generator & Integrated Buffers for PENTIUM/Pro TM General Description The ICS9248-103 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 8d B to 10d B. This simplifies EMI qualification without resorting to board design iterations or costly shielding. The ICS9248-103 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 3 free running PCICLK_Fs) - 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 Power Groups VDDLCPU, GNDLCPU = CPUCLK [2:0], CPUCLK_F VDDSDR, GNDSDR = SDRAMCLKS [7:0], SDRAM_F VDDPCI, GNDPCI = PCICLKS [6:0], PCICLK_F VDD48, GND48 = 48MHz, 24MHz VDDREF, GNDREF = REF, X1, X2 VDDCOR = PLL CORE 9248-103 Rev C 10/14/99 48-Pin SSOP - Internal Pull-up Resistor of 120K to VDD Pentium is a trademark of Intel Corporation I2C is a trademark of Philips Corporation ICS reserves the right to make changes in the device data identified in this publication without further notice. ICS advises its customers to obtain the latest version of all device data to verify that any information being relied upon by the customer is current and accurate. Pin Descriptions PIN NUMBER 1 2 20 3, 9, 16, 33, 40, 44 4 5...