MK1491-06S

Overview

The MK1491-06S is a clock synthesizer IC designed for AMD Geode-based computer and portable appliance applications. It accepts a 14.318 MHz crystal input to generate multiple output clocks, including selectable PCI local bus, AC97 audio, 24 MHz, and 48 MHz clocks. The device operates within a supply voltage range of 3.15V to 3.45V and supports a maximum frequency of 49.152MHz. It features a 1:10 input-to-output ratio, LVCMOS outputs, and no differential signaling. Packaged in a 28-SOIC case with a width of 7.50mm, it functions within an operating temperature range of 0°C to 70°C.

Feature Summary

• Generates critical timing for AMD Geode companion chips, including four PCI clocks and AC97 audio support.
• Features patented Low EMI Enable pin to reduce radiation on PCI clocks.
• Includes multiple power-down modes to minimize power consumption.
• Provides selectable PCIF functionality on up to two outputs.

Applications

• AMD Geode-based desktop computers
• Portable appliance systems
• Super I/O and USB clock generation (24 MHz/48 MHz)

Procurement Notes

Verify component authenticity through authorized Renesas or IDT distributors. Confirm RoHS compliance status as the standard part may contain lead; check for 'LF' suffix variants if lead-free requirements apply. Ensure ordering suffixes match the required packaging format, such as tubes for the 'S' designation.

Selection Notes

Select this component when designing for AMD Geode platforms requiring specific PCI and AC97 clock frequencies. Ensure the design accommodates the 28-SOIC package dimensions and 3.3V ±5% power supply constraints. Verify that external decoupling capacitors (0.1µF) and series termination resistors (33Ω) are included in the schematic for proper operation.

Part Context

This part belongs to the MK1491-06 family of clock synthesizers originally developed by Integrated Device Technology (IDT) and later acquired by Renesas Electronics. It serves as a dedicated clock source solution for legacy AMD Geode processors, replacing earlier discrete timing solutions with a single integrated circuit.

Replacement Considerations

Direct replacements include other parts from the MK1491-06 family, such as MK1491-06R (SSOP package) or MK1491-06RLF (lead-free SSOP). Cross-package equivalents like MK1491-09 series exist but differ in output ratios and frequencies; verify electrical compatibility before substitution.