ICS97U877AK PLL Clock Driver Equivalent & Substitute Parts

Part Overview

The ICS97U877AK is a PLL clock driver IC manufactured by Renesas Electronics Corporation, designed for DDR2 memory applications. This 40-VFQFN surface mount device operates at 370MHz maximum frequency with SSTL-18 input/output signaling and a 1:10 input-to-output ratio. The part is classified as obsolete, making equivalent substitutes from active manufacturers necessary for new designs and ongoing production requirements.

Substiute Parts

ICS97U877AK

Renesas Electronics CorporationIn Stock: 2089ICS97U877AK Datasheet

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CDCU877ARHAR

Texas InstrumentsIn Stock: 2946CDCU877ARHAR Datasheet

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CDCU877ARHAT

Texas InstrumentsIn Stock: 1515CDCU877ARHAT Datasheet

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CDCU877RHAR

Texas InstrumentsIn Stock: 2716CDCU877RHAR Datasheet

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CDCU877RHAT

Texas InstrumentsIn Stock: 1654CDCU877RHAT Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the ICS97U877AK are qualified based on the following critical parameters that must match or exceed the original specification:

Mandatory Matching Parameters:

• Package / Case: 40-VFQFN Exposed Pad (6x6) — physical and electrical compatibility
• Input Signal: SSTL-18 — interface standard compatibility
• Output Signal: SSTL-18 — interface standard compatibility
• Ratio - Input:Output: 1:10 — functional equivalence
• Differential - Input:Output: Yes/Yes — signal type compatibility
• Number of Circuits: 1 — functional equivalence
• Voltage - Supply: 1.7V ~ 1.9V — power supply compatibility
• Mounting Type: Surface Mount — assembly compatibility

Performance Parameters:

• Frequency - Max: Substitute parts must support 370MHz or higher
• Operating Temperature: Substitute parts must support the required temperature range or broader

All four substitute parts (CDCU877RHAR, CDCU877RHAT, CDCU877ARHAR, CDCU877ARHAT) from Texas Instruments meet these criteria and are manufactured by an active supplier with current product status.

Parameter Comparison

Engineering Selection Recommendations

All four Texas Instruments CDCU877 variants (CDCU877RHAR, CDCU877RHAT, CDCU877ARHAR, CDCU877ARHAT) are direct functional equivalents to the ICS97U877AK. Selection among these variants should be based on the following factors:

Product Status: The ICS97U877AK is obsolete. All substitute parts carry active product status from Texas Instruments, ensuring long-term availability and manufacturing support.

Compliance: The Texas Instruments CDCU877 series is ROHS3 compliant, whereas the original ICS97U877AK is RoHS non-compliant. This compliance upgrade is beneficial for new designs and regulatory requirements.

Performance Margin: All substitute parts support 400MHz maximum frequency, exceeding the original 370MHz specification. This provides additional performance headroom.

Operating Temperature Range: The Texas Instruments parts support -40°C to 85°C, which exceeds the original 0°C to 70°C range, providing broader environmental compatibility.

Packaging: All substitute parts are supplied in Tape & Reel (TR) format, suitable for automated assembly processes.

Frequently Asked Questions (FAQ)

Q: Can CDCU877RHAR, CDCU877RHAT, CDCU877ARHAR, and CDCU877ARHAT be used interchangeably with ICS97U877AK?

A: Yes. All four Texas Instruments parts are functionally equivalent. They share identical electrical specifications for supply voltage (1.7V ~ 1.9V), input/output signaling (SSTL-18), frequency ratio (1:10), differential signal configuration, and package form factor (40-VFQFN Exposed Pad). The differences between the four variants relate to temperature grade and packaging options, not core functionality.

Q: What is the difference between the four CDCU877 variants?

A: The variants differ in temperature grade designation (R vs. AR prefix) and tape orientation (HAR vs. HAT suffix). These differences affect tape reel configuration and temperature specifications but do not impact electrical functionality or package compatibility. Consult Texas Instruments documentation for specific tape reel orientation requirements for your assembly equipment.

Q: Is the higher maximum frequency (400MHz vs. 370MHz) of the substitute parts a concern?

A: No. The 400MHz specification of the CDCU877 series represents a performance upgrade. The substitute parts are backward compatible with designs requiring 370MHz operation. The higher frequency rating provides additional design margin and future-proofing.

Q: Does the extended operating temperature range (-40°C to 85°C) of the substitute parts affect compatibility?

A: No. The extended temperature range is a superset of the original specification (0°C to 70°C). Designs operating within the original temperature range will function identically with the substitute parts. The extended range provides additional flexibility for applications with broader environmental requirements.

Q: Are there any package or pinout differences between ICS97U877AK and the CDCU877 series?

A: No. Both the original and substitute parts use the 40-VFQFN Exposed Pad package (6x6mm). Pinout and package dimensions are identical, enabling direct board-level substitution without layout modifications.

Q: What is the impact of RoHS3 compliance on the substitute parts?

A: RoHS3 compliance indicates that the CDCU877 series meets current environmental and hazardous substance restrictions. This is an improvement over the non-compliant original part and is required for many modern applications and markets.

Q: Which CDCU877 variant should I select for new designs?

A: All four variants are suitable for new designs. Selection should be based on your assembly equipment's tape reel orientation requirements (HAR vs. HAT) and any specific temperature grade needs. Consult your manufacturing partner and Texas Instruments documentation for guidance on tape configuration compatibility.