SN74LS390DR Equivalent & Substitute Parts

Part Overview

The SN74LS390DR is a decade counter IC manufactured by Texas Instruments, featuring dual 4-bit negative edge-triggered counters in a 16-SOIC surface mount package. This component is classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing design support and production requirements. The part operates within the 74LS logic family standard and maintains compatibility with 5V TTL systems.

Substiute Parts

SN74LS390DR

Texas InstrumentsIn Stock: 936SN74LS390DR Datasheet

Current PartRFQ

SN74LS390D

Texas InstrumentsIn Stock: 1597SN74LS390D Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74LS390DR is determined by strict equivalence across the following critical parameters:

• Logic Type: Counter, Decade (2 Element, 4 Bit configuration)
• Trigger Type: Negative Edge
• Count Rate: 35 MHz minimum
• Voltage Supply Range: 4.75 V ~ 5.25 V
• Package / Case: 16-SOIC surface mount
• Reset Function: Asynchronous
• Operating Temperature Range: 0°C ~ 70°C

The SN74LS390D qualifies as a direct substitute based on identical electrical specifications and package configuration. The primary distinction is product status and packaging format, with the substitute part currently in active production status.

Parameter Comparison

Engineering Selection Recommendations

The SN74LS390D is the direct equivalent for the obsolete SN74LS390DR. Both parts share identical electrical characteristics, pin configuration, and functional specifications. The substitute part maintains active production status with Texas Instruments, ensuring long-term availability and supply chain continuity.

Both parts comply with ROHS3 and REACH regulatory requirements, with MSL rating of 1 (Unlimited), indicating no moisture sensitivity constraints during storage and handling. The transition from the obsolete SN74LS390DR to the active SN74LS390D presents no functional or compliance risks for circuit implementation.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS390D directly replace the SN74LS390DR in existing designs?

A: Yes. The SN74LS390D is electrically and mechanically identical to the SN74LS390DR. Pin configuration, voltage requirements, timing specifications, and package dimensions are equivalent. No circuit modifications are required.

Q: What is the primary difference between these parts?

A: The SN74LS390DR is obsolete, while the SN74LS390D is in active production. The substitute part ensures continued availability and supply chain support.

Q: Are there any packaging differences?

A: Both parts use 16-SOIC surface mount packaging. The SN74LS390DR is supplied in standard packaging, while the SN74LS390D is supplied in tube packaging format. This does not affect electrical performance or PCB assembly compatibility.

Q: Do both parts meet current regulatory standards?

A: Yes. Both the SN74LS390DR and SN74LS390D are ROHS3 compliant and REACH unaffected, with MSL rating of 1 (Unlimited).

Q: What are the critical substitution parameters for this counter IC?

A: Substitution is valid when the following parameters match: Logic Type (Counter, Decade), Number of Elements (2), Bits per Element (4), Trigger Type (Negative Edge), Count Rate (35 MHz), Supply Voltage (4.75 V ~ 5.25 V), Package (16-SOIC), and Operating Temperature Range (0°C ~ 70°C).