DM74LS123M Equivalent & Substitute Parts

Part Overview

The DM74LS123M is a monostable multivibrator logic IC manufactured by onsemi in 16-SOIC surface mount packaging. This component features dual independent circuits with 45 ns propagation delay and operates within the 4.75 V to 5.25 V supply voltage range. The part is classified as obsolete, making equivalent substitutes necessary for ongoing design support and procurement.

Substiute Parts

DM74LS123M

onsemiIn Stock: 1983DM74LS123M Datasheet

Current PartRFQ

SN74LS123D

Texas InstrumentsIn Stock: 1974SN74LS123D Datasheet

DirectRFQ

SN74LS123DE4

Texas InstrumentsIn Stock: 800SN74LS123DE4 Datasheet

DirectRFQ

SN74LS123DR

Texas InstrumentsIn Stock: 45487SN74LS123DR Datasheet

DirectRFQ

SN74LS123NSR

Texas InstrumentsIn Stock: 4542SN74LS123NSR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DM74LS123M is determined by the following critical parameters:

• Logic Type: Monostable Multivibrator
• Independent Circuits: 2
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 16-SOIC surface mount
• Current - Output High, Low: 400µA, 8mA

All substitute parts listed maintain these core electrical and mechanical specifications. Propagation delay variations (28 ns vs. 45 ns) represent performance improvements and do not prevent functional substitution. Package width variations (0.154" vs. 0.209") indicate different SOIC body sizes but maintain 16-pin SOIC compatibility.

Parameter Comparison

Engineering Selection Recommendations

Direct Substitutes (Identical Package Geometry):

SN74LS123D, SN74LS123DE4, and SN74LS123DR are direct substitutes for the DM74LS123M. All three maintain the 16-SOIC (0.154", 3.90mm Width) package specification and are manufactured by Texas Instruments. SN74LS123DR offers the highest inventory availability (45,384 pcs) and active product status. SN74LS123D is available in tube packaging with 1,917 pcs in stock. SN74LS123DE4 is discontinued at DiGi Electronics with 757 pcs remaining. All three are ROHS3 compliant, providing regulatory advantage over the non-compliant DM74LS123M.

Package Variant Substitute:

SN74LS123NSR is functionally equivalent but uses a wider 16-SOIC (0.209", 5.30mm Width) package body. This part is supplied in tape and reel format with 4,475 pcs in stock and active product status. PCB layout modifications are required to accommodate the increased package width.

Frequently Asked Questions (FAQ)

Q: Can SN74LS123D replace DM74LS123M directly on the PCB?

A: Yes. SN74LS123D maintains identical package geometry (16-SOIC 0.154" width), pin configuration, and all critical electrical parameters. No PCB modifications are required.

Q: What is the difference between SN74LS123D, SN74LS123DE4, and SN74LS123DR?

A: All three are functionally identical Texas Instruments parts with 28 ns propagation delay. The differences are packaging format (tube vs. cut tape/reel) and product status. SN74LS123DR is recommended for new designs due to active status and highest inventory.

Q: Why does SN74LS123NSR have a different package width?

A: SN74LS123NSR uses a 16-SO package body (0.209" width) instead of the standard 16-SOIC (0.154" width). Both are 16-pin surface mount packages with identical pin spacing, but the wider body requires PCB footprint adjustment.

Q: Is the 28 ns propagation delay of Texas Instruments parts compatible with designs specified for 45 ns?

A: Yes. The 28 ns propagation delay is faster than the 45 ns specification of the DM74LS123M. Faster propagation delay does not create functional incompatibility in circuits designed for the original 45 ns timing.

Q: Are all substitute parts RoHS compliant?

A: All Texas Instruments substitutes (SN74LS123D, SN74LS123DE4, SN74LS123DR, SN74LS123NSR) are ROHS3 compliant. The original DM74LS123M is RoHS non-compliant.