CDCU877ZQLT Equivalent & Substitute Parts

Part Overview

The CDCU877ZQLT is a DDR2 memory clock buffer/driver IC manufactured by Texas Instruments, designed for high-speed clock distribution in memory subsystems. This device features a 1:10 input-to-output ratio with differential signaling on both input and output, operating at frequencies up to 400MHz with 1.8V supply voltage compatibility.

The CDCU877ZQLT is classified as obsolete. Identifying suitable substitute parts is necessary for ongoing system support, design updates, and procurement continuity when original inventory becomes unavailable.

Substiute Parts

CDCU877ZQLT

Texas InstrumentsIn Stock: 1415CDCU877ZQLT Datasheet

Current PartRFQ

98ULPA877AHT

Renesas Electronics CorporationIn Stock: 83598ULPA877AHT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the CDCU877ZQLT is determined by the following critical parameters:

• Package Type: 52-BGA form factor (physical and electrical compatibility)
• Input/Output Standards: SSTL-18 differential signaling on both input and output
• Frequency Performance: Maximum operating frequency of 400MHz or higher
• Supply Voltage Range: 1.7V ~ 1.9V compatibility
• Functional Architecture: 1:10 input-to-output ratio with PLL capability
• Circuit Count: Single circuit configuration
• Mounting: Surface mount technology

The 98ULPA877AHT from Renesas Electronics Corporation meets these substitution criteria with compatible electrical specifications and package dimensions, though with noted differences in product status and environmental compliance ratings.

Parameter Comparison

Engineering Selection Recommendations

The 98ULPA877AHT qualifies as a functional substitute for the CDCU877ZQLT based on matching electrical specifications, package form factor, and DDR2 memory clock driver application requirements. Both devices share identical supply voltage ranges, input-to-output ratios, and differential signaling architecture.

Key distinctions for selection:

Product Status: The 98ULPA877AHT maintains active production status, ensuring long-term availability and supply chain continuity compared to the obsolete CDCU877ZQLT.

Compliance Considerations: The CDCU877ZQLT carries ROHS3 compliance certification, while the 98ULPA877AHT is RoHS non-compliant. Systems with RoHS compliance requirements must account for this difference in material composition and environmental regulations.

Environmental Specifications: The CDCU877ZQLT operates across -40°C to 85°C with MSL rating of 2 (1 Year), while the 98ULPA877AHT operates 0°C to 70°C with MSL rating of 3 (168 Hours). Operating temperature range and moisture handling requirements must align with system specifications.

Frequency Margin: The 98ULPA877AHT provides 10MHz additional frequency headroom (410MHz vs. 400MHz), offering performance margin for clock distribution applications.

Frequently Asked Questions (FAQ)

Q: Can the 98ULPA877AHT directly replace the CDCU877ZQLT in existing designs?

A: Electrical and package compatibility is confirmed. However, verify operating temperature requirements (-40°C to 85°C for CDCU877ZQLT vs. 0°C to 70°C for 98ULPA877AHT) and RoHS compliance status (ROHS3 vs. non-compliant) against your system specifications before implementation.

Q: What are the key electrical parameters that determine substitution compatibility?

A: The critical parameters are: 52-BGA package form factor, SSTL-18 differential output standard, 1:10 input-to-output ratio, 1.7V ~ 1.9V supply voltage range, and maximum frequency of 400MHz or higher. Both devices meet these requirements.

Q: How do the moisture sensitivity levels differ between these parts?

A: The CDCU877ZQLT has MSL 2 (1 Year shelf life), while the 98ULPA877AHT has MSL 3 (168 Hours shelf life). MSL 3 requires more stringent moisture control during storage and handling. Verify your manufacturing process capabilities for MSL 3 compliance.

Q: Are there operating temperature restrictions when substituting?

A: Yes. The CDCU877ZQLT operates from -40°C to 85°C, while the 98ULPA877AHT operates from 0°C to 70°C. If your application requires operation below 0°C or above 70°C, the 98ULPA877AHT is not suitable.

Q: What is the significance of the "LP" designation in the 98ULPA877AHT part number?

A: The "LP" designation indicates low-power operation. This device is optimized for reduced power consumption compared to standard variants, which may be relevant for power-sensitive applications.