SN74145NSR Equivalent & Substitute Parts

Part Overview

The SN74145NSR is a 1 x 4:10 decoder logic IC manufactured by Texas Instruments in the 7400 series. This component decodes a 4-bit binary input into one of ten mutually exclusive outputs, commonly used in address decoding and selection applications. The part is classified as obsolete, making equivalent substitutes necessary for new designs and ongoing production support. The SN74LS145NSR provides a direct functional replacement while maintaining active product status and improved availability.

Substiute Parts

SN74145NSR

Texas InstrumentsIn Stock: 826SN74145NSR Datasheet

Current PartRFQ

SN74LS145NSR

Texas InstrumentsIn Stock: 3310SN74LS145NSR Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

The SN74LS145NSR qualifies as a parametric equivalent to the SN74145NSR based on the following critical substitution criteria:

Functional Parameters (Must Match):

• Decoder circuit configuration: 1 x 4:10
• Independent circuits: 1
• Output current rating: 80mA (low)
• Supply voltage range: 4.75V ~ 5.25V
• Operating temperature range: 0°C ~ 70°C

Physical Parameters (Must Match):

• Package type: 16-SOIC
• Package dimensions: 0.209" width (5.30mm)
• Mounting type: Surface Mount

Compliance Parameters (Must Match):

• RoHS3 Compliant
• Moisture Sensitivity Level: 1 (Unlimited)
• REACH Status: REACH Unaffected

The SN74LS145NSR belongs to the 74LS logic family, which is a low-power Schottky variant of the standard 7400 series. Both parts maintain identical electrical specifications within the specified operating ranges and are housed in the same 16-SOIC package, enabling direct pin-compatible substitution.

Parameter Comparison

Engineering Selection Recommendations

For New Designs: The SN74LS145NSR is the recommended selection. It maintains full electrical and mechanical compatibility with the SN74145NSR while offering active product status, ensuring long-term availability and supply chain stability. Both parts are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements.

For Legacy System Maintenance: The SN74145NSR remains functionally equivalent for existing applications. However, due to obsolete status, sourcing may be limited. The SN74LS145NSR provides identical performance characteristics and serves as a direct replacement without design modification.

Compliance Considerations: Both parts satisfy ROHS3 compliance and carry unlimited moisture sensitivity classification (MSL 1), suitable for standard storage and handling conditions without special precautions.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS145NSR directly replace the SN74145NSR without PCB modifications?

A: Yes. Both parts are pin-compatible 16-SOIC packages with identical pinout, electrical specifications, and functional behavior. No PCB layout changes are required.

Q: What is the primary difference between the SN74145NSR and SN74LS145NSR?

A: The SN74LS145NSR uses low-power Schottky (LS) technology, reducing power consumption compared to standard 7400 series logic. Both maintain identical output current ratings and voltage specifications within the specified operating range.

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

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

Q: Why is the SN74145NSR marked as obsolete?

A: The SN74145NSR has reached end-of-life status. Texas Instruments continues to support the 74LS variant (SN74LS145NSR) as the active product line for this decoder function.

Q: Do both parts require the same handling and storage conditions?

A: Yes. Both parts carry MSL 1 (Unlimited) moisture sensitivity classification, indicating no special moisture control or baking requirements for standard storage and assembly processes.

Q: Is the SN74LS145NSR available in the same packaging options?

A: The SN74LS145NSR is available in Cut Tape (CT) and Digi-Reel packaging formats, with significantly higher inventory availability compared to the obsolete SN74145NSR.