74VCX16821MTD Equivalent & Substitute Parts

Part Overview

The 74VCX16821MTD is a dual 10-bit D-type flip-flop logic integrated circuit manufactured by onsemi, housed in a 56-TFSOP surface mount package. This device functions as a standard positive edge-triggered flip-flop with tri-state, non-inverted outputs, operating across a supply voltage range of 1.4V to 3.6V with a maximum clock frequency of 250 MHz.

The 74VCX16821MTD is classified as obsolete. Equivalent substitute parts are available from active product lines, primarily from Texas Instruments, which maintain functional and electrical compatibility while offering continued availability and support.

Substiute Parts

74VCX16821MTD

onsemiIn Stock: 90474VCX16821MTD Datasheet

Current PartRFQ

SN74ALVCH16821DGG

Texas InstrumentsIn Stock: 958SN74ALVCH16821DGG Datasheet

SimilarRFQ

SN74ALVCH16821DGGR

Texas InstrumentsIn Stock: 5882SN74ALVCH16821DGGR Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74VCX16821MTD is determined by the following critical parameters:

• Functional equivalence: D-Type flip-flop with 2 elements, 10 bits per element, tri-state non-inverted outputs, positive edge trigger
• Package compatibility: 56-TFSOP surface mount package with identical pin configuration
• Electrical compatibility: Supply voltage range, output drive capability (24mA), and operating temperature range
• Timing performance: Maximum propagation delay and clock frequency specifications

The substitute parts identified—SN74ALVCH16821DGG and SN74ALVCH16821DGGR from Texas Instruments—maintain functional and electrical compatibility with the 74VCX16821MTD across all critical parameters. Both substitute parts operate within the same package, support the same logic function, and meet the required electrical specifications for direct replacement in existing designs.

Parameter Comparison

Engineering Selection Recommendations

Both SN74ALVCH16821DGG and SN74ALVCH16821DGGR from Texas Instruments are suitable replacements for the obsolete 74VCX16821MTD. Selection between the two Texas Instruments variants depends on packaging requirements:

• SN74ALVCH16821DGG: Standard packaging format, suitable for applications where tape and reel packaging is not required.
• SN74ALVCH16821DGGR: Tape and reel packaging, optimized for high-volume automated assembly processes.

Both substitute parts are ROHS3 compliant and carry active product status, ensuring long-term availability and manufacturer support. The Texas Instruments parts operate at a lower maximum clock frequency (150 MHz versus 250 MHz) and exhibit slightly higher quiescent current (40 µA versus 20 µA), but maintain full functional and electrical compatibility for standard logic applications within the specified operating parameters.

Frequently Asked Questions (FAQ)

Q: Can SN74ALVCH16821DGG and SN74ALVCH16821DGGR be used interchangeably with 74VCX16821MTD?

A: Yes. Both Texas Instruments parts maintain identical functional specifications, package configuration, and electrical compatibility. The primary difference is packaging format: SN74ALVCH16821DGG uses standard packaging, while SN74ALVCH16821DGGR uses tape and reel packaging for automated assembly.

Q: What are the differences in clock frequency between the main part and substitutes?

A: The 74VCX16821MTD supports a maximum clock frequency of 250 MHz, while both SN74ALVCH16821 variants support 150 MHz. For applications operating below 150 MHz, this difference is not a limiting factor. Applications requiring operation above 150 MHz must retain the original 74VCX16821MTD or identify alternative solutions.

Q: Are there differences in propagation delay specifications?

A: The 74VCX16821MTD specifies 4.6ns maximum propagation delay at 3.3V with 30pF load, while the SN74ALVCH16821 variants specify 4.5ns at 3.3V with 50pF load. The longer delay in the substitute parts reflects different test conditions and load capacitance. For timing-critical applications, verify that the 4.5ns specification meets system requirements.

Q: What is the difference between the two Texas Instruments part numbers?

A: SN74ALVCH16821DGG and SN74ALVCH16821DGGR are functionally identical. The "R" suffix in SN74ALVCH16821DGGR indicates tape and reel packaging for high-volume production. Select based on your assembly process requirements.

Q: Are the supply voltage ranges compatible?

A: The 74VCX16821MTD operates from 1.4V to 3.6V, while the SN74ALVCH16821 variants operate from 1.65V to 3.6V. The substitute parts have a slightly higher minimum supply voltage. For applications operating below 1.65V, the original part must be retained.

Q: What compliance certifications apply to these parts?

A: The SN74ALVCH16821DGG and SN74ALVCH16821DGGR are ROHS3 compliant. Both the original and substitute parts carry MSL 1 (Unlimited) moisture sensitivity ratings and are classified under ECCN EAR99 for export purposes.