ICS951413CGLFT

Overview

The ICS951413 is a programmable system clock chip designed for ATI RS400-based systems utilizing Intel P4 processors. It generates CPU outputs up to 400MHz and provides highly accurate SRC clocks for PCI-Express support. The device operates with a 14.318MHz crystal input and delivers multiple output pairs, including six pairs of SRC/PCI Express clocks, three pairs of Intel P4 clocks, and fixed reference frequencies. It features cycle-cycle jitter specifications of less than 85ps for CPU outputs and supports spread spectrum modulation for EMI reduction.

Feature Summary

• Generates CPU outputs up to 400MHz with cycle-cycle jitter under 85ps
• Provides six pairs of SRC/PCI Express clocks and two pairs of programmable ATIG clocks
• Supports SMBus control for frequency selection and output enable/disable functions
• Includes spread spectrum capability for electromagnetic interference (EMI) reduction

Applications

• ATI RS400 chipset systems using Intel P4 mobile processors
• Motherboards requiring precise timing for PCI Express interfaces
• Systems needing programmable clock generation for CPU and peripheral buses

Procurement Notes

Verify the specific revision ID and package variant when sourcing, as the component was originally manufactured by Integrated Circuit Systems, Inc. before its acquisition. Confirm that the supply voltage matches the required 3.3V nominal range with +/-5% tolerance. Ensure external components such as the 475 ohm reference resistor are included in the design, as they are critical for establishing the correct current mode output levels.

Selection Notes

Select this component for designs based on the ATI RS400 platform requiring integrated clock generation for P4 CPUs and PCIe links. It is suitable for applications needing programmable frequency tables via latch inputs or SMBus. Consider the 56-TSSOP package constraints and the requirement for external load capacitors on the crystal pins to ensure maximum frequency accuracy within the specified operating temperature range.

Part Context

The ICS951413 was produced by Integrated Circuit Systems, Inc., which was acquired by Renesas Electronics Corporation. This part belongs to the family of programmable clock generators targeted at desktop and mobile PC architectures from the mid-2000s era. It serves as a specialized timing solution for specific chipset combinations rather than a general-purpose clock generator.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Designers should consult original equipment manufacturer guidelines for legacy replacements or verify compatibility with newer clock generator families if migrating off the ATI RS400 platform.