SN74LS90D Equivalent & Substitute Parts

Part Overview

The SN74LS90D is a decade counter integrated circuit manufactured by Texas Instruments, classified as a 4-bit logic counter in the 74LS series. This component functions as a negative edge-triggered counter with asynchronous reset capability, designed for applications requiring decimal counting operations. The SN74LS90D is currently in Last Time Buy status, indicating discontinued production. Identifying equivalent substitute parts is necessary to ensure design continuity and maintain supply chain reliability for ongoing production and maintenance applications.

Substiute Parts

SN74LS90D

Texas InstrumentsIn Stock: 698SN74LS90D Datasheet

Current PartRFQ

SN74LS90DR

Texas InstrumentsIn Stock: 2186SN74LS90DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74LS90D is determined by strict equivalence across the following critical parameters:

• Logic Type: Counter, Decade (1 Element, 4 Bit)
• Trigger Type: Negative Edge
• Reset Configuration: Asynchronous
• Count Rate: 42 MHz minimum
• Supply Voltage Range: 4.75 V ~ 5.25 V
• Package / Case: 14-SOIC form factor
• Mounting Type: Surface Mount
• Operating Temperature Range: 0°C ~ 70°C minimum

The SN74LS90DR qualifies as a direct substitute because it maintains identical electrical specifications, functional characteristics, and physical packaging. Both parts share the same base product number (74LS90) and are manufactured by Texas Instruments within the same 74LS logic series.

Parameter Comparison

Engineering Selection Recommendations

The SN74LS90DR is the manufacturer-recommended substitute for the SN74LS90D. Both parts are manufactured by Texas Instruments and maintain complete electrical and mechanical compatibility. The primary distinction is product status: the SN74LS90D is in Last Time Buy phase, while the SN74LS90DR maintains Active status with higher inventory availability (2116 pcs vs. 653 pcs).

Both parts satisfy ROHS3 compliance and REACH unaffected status, ensuring regulatory alignment for applications subject to environmental standards. The packaging difference between Tube (SN74LS90D) and Cut Tape & Digi-Reel (SN74LS90DR) reflects distribution format only and does not affect functional or electrical performance.

For new designs or production transitions, the SN74LS90DR is the appropriate selection due to its active product status and sustained supply availability.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS90DR directly replace the SN74LS90D in existing designs?

A: Yes. The SN74LS90DR is electrically and mechanically identical to the SN74LS90D. Pin configuration, electrical characteristics, timing specifications, and package dimensions are equivalent. No circuit modifications are required.

Q: What is the difference between Tube and Cut Tape & Digi-Reel packaging?

A: Packaging format affects distribution and handling only. Tube packaging is used for smaller quantities, while Cut Tape & Digi-Reel is used for higher-volume production runs. The integrated circuit itself is identical in both formats.

Q: Why is the SN74LS90D listed as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments has discontinued production of this part number. Existing inventory is available for a limited time. The SN74LS90DR remains in active production and is the recommended long-term alternative.

Q: Are there any temperature or voltage derating considerations when substituting?

A: No. Both parts operate within the identical voltage range (4.75 V ~ 5.25 V) and temperature range (0°C ~ 70°C). No derating or design adjustments are necessary.

Q: Do both parts meet the same compliance standards?

A: Yes. Both the SN74LS90D and SN74LS90DR are ROHS3 compliant and REACH unaffected, meeting the same environmental and regulatory requirements.