NA556D Equivalent & Substitute Parts

Part Overview

The NA556D is a dual timer/oscillator integrated circuit manufactured by Texas Instruments, designed for clock and timing applications. It operates as a 555-type timer in a 14-SOIC surface mount package. The NA556D is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. The active substitute NA556DR provides functional continuity while maintaining full electrical and mechanical compatibility.

Substiute Parts

NA556D

Texas InstrumentsIn Stock: 4927NA556D Datasheet

Current PartRFQ

NA556DR

Texas InstrumentsIn Stock: 30496NA556DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the NA556D is determined by strict equivalence across the following critical parameters:

• Functional Type: 555-type dual timer/oscillator IC
• Electrical Specifications: Identical supply voltage range (4.5V ~ 16V) and supply current (20 mA)
• Temperature Rating: Matching operating temperature range (-40°C ~ 105°C)
• Package Specification: Identical 14-SOIC package with 0.154" width (3.90mm)
• Mounting Technology: Surface mount configuration
• Compliance Standards: ROHS3 compliance and MSL Level 1 rating

The NA556DR qualifies as a direct substitute based on complete alignment with all specified parameters. The primary distinction is product status: NA556D is obsolete while NA556DR is active, and packaging format differs (tube versus cut tape/digi-reel).

Parameter Comparison

Engineering Selection Recommendations

The NA556DR is the direct equivalent for the obsolete NA556D. Selection of NA556DR is appropriate for:

• New design implementations requiring 555-type dual timer functionality
• Production continuity where NA556D inventory is depleted
• Applications requiring active product status and ongoing manufacturer support

Both parts maintain identical electrical performance, thermal characteristics, and compliance certifications. The NA556DR's active status ensures availability and manufacturer backing. Packaging format selection (cut tape/digi-reel versus tube) depends on procurement volume and assembly process requirements.

Frequently Asked Questions (FAQ)

Q: Can NA556DR be used as a direct replacement for NA556D in existing designs?

A: Yes. The NA556DR is electrically and mechanically identical to the NA556D across all specified parameters: supply voltage (4.5V ~ 16V), supply current (20 mA), operating temperature range (-40°C ~ 105°C), and 14-SOIC package configuration. Pin-for-pin compatibility is maintained.

Q: What is the primary reason for substitution?

A: The NA556D is classified as obsolete. The NA556DR provides functional continuity as an active product from the same manufacturer with identical specifications.

Q: Are there differences in packaging that affect component selection?

A: Yes. The NA556D is supplied in tube packaging, while the NA556DR is available in cut tape and digi-reel formats. Packaging selection should align with assembly process requirements and order quantities.

Q: Do both parts meet the same compliance standards?

A: Yes. Both the NA556D and NA556DR are ROHS3 compliant with MSL Level 1 (unlimited moisture sensitivity rating), ensuring equivalent environmental and regulatory compliance.

Q: Is the 14-SOIC package identical between both parts?

A: Yes. Both parts use the identical 14-SOIC package with 0.154" width (3.90mm), ensuring PCB footprint compatibility and surface mount assembly without modification.