SN74LS251NG4 Equivalent & Substitute Parts

Part Overview

The SN74LS251NG4 is a 1 x 8:1 multiplexer logic integrated circuit manufactured by Texas Instruments in a 16-DIP package. This component is discontinued at DiGi Electronics and classified as obsolete in current distribution channels. Finding equivalent substitute parts is necessary to maintain design continuity and ensure component availability for production, repair, and legacy system support.

Substiute Parts

SN74LS251NG4

Texas InstrumentsIn Stock: 994SN74LS251NG4 Datasheet

Current PartRFQ

SN74LS251N

onsemiIn Stock: 4353SN74LS251N Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74LS251NG4 is determined by strict equivalence across the following critical parameters:

• Circuit configuration: 1 x 8:1 multiplexer topology
• Package type: 16-DIP (0.300", 7.62mm) for mechanical and pin compatibility
• Electrical specifications: Voltage supply range 4.75V ~ 5.25V, output current ratings 2.6mA (high) and 8mA (low)
• Operating temperature range: 0°C ~ 70°C
• Series classification: 74LS logic family

The substitute part SN74LS251N meets all these criteria and maintains functional and electrical equivalence with the original component.

Parameter Comparison

Engineering Selection Recommendations

The SN74LS251N manufactured by onsemi is the direct functional equivalent to the SN74LS251NG4. Both components share identical electrical specifications, circuit configuration, and package dimensions, ensuring pin-for-pin compatibility and circuit-level interchangeability.

When selecting between these parts, consider the following factors based on provided specifications:

• RoHS compliance requirements: The original SN74LS251NG4 is ROHS3 compliant, while the SN74LS251N is RoHS non-compliant. Applications subject to RoHS regulations should prioritize the compliant variant.
• Product availability: The SN74LS251N has higher inventory availability (4300 pcs) compared to the SN74LS251NG4 (917 pcs).
• Manufacturer source: Both components are from established semiconductor manufacturers (Texas Instruments and onsemi) within the 74LS logic family.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS251N be used as a direct replacement for the SN74LS251NG4?

A: Yes. Both components are 1 x 8:1 multiplexers with identical electrical specifications (4.75V ~ 5.25V supply, 2.6mA/8mA output current), operating temperature range (0°C ~ 70°C), and 16-DIP package dimensions. They are pin-for-pin compatible and functionally equivalent.

Q: What is the difference between these two parts?

A: The primary differences are manufacturer (Texas Instruments vs. onsemi) and RoHS compliance status. The SN74LS251NG4 is ROHS3 compliant, while the SN74LS251N is not. Both are 74LS series logic multiplexers with identical circuit performance.

Q: Are there any package or mounting differences?

A: No. Both parts use the same 16-DIP (0.300", 7.62mm) package with through-hole mounting. They are mechanically and electrically interchangeable in PCB designs.

Q: Which part should I select for new designs?

A: Selection depends on regulatory requirements. For RoHS-compliant applications, the SN74LS251NG4 is the appropriate choice. For applications without RoHS constraints, either part is suitable based on availability and cost considerations.

Q: What is the operating temperature range for these multiplexers?

A: Both the SN74LS251NG4 and SN74LS251N operate across 0°C to 70°C, suitable for commercial and industrial applications within this temperature specification.