74VHC123ASJ Equivalent & Substitute Parts

Part Overview

The 74VHC123ASJ is a monostable multivibrator logic IC manufactured by onsemi, featuring dual independent circuits with 8.1 ns propagation delay in a 16-SOIC surface mount package. The product is currently obsolete, making equivalent and substitute parts necessary for ongoing design support, production continuity, and system maintenance. Substitute parts must maintain functional compatibility across the monostable multivibrator logic category while meeting the electrical and mechanical requirements of the original design.

Substiute Parts

74VHC123ASJ

onsemiIn Stock: 548374VHC123ASJ Datasheet

Current PartRFQ

SN74LV123ANSR

Texas InstrumentsIn Stock: 3241SN74LV123ANSR Datasheet

DirectRFQ

74AHC123AD,118

Nexperia USA Inc.In Stock: 681274AHC123AD,118 Datasheet

SimilarRFQ

SN74AHC123AD

Texas InstrumentsIn Stock: 1948SN74AHC123AD Datasheet

SimilarRFQ

SN74AHC123ADR

Texas InstrumentsIn Stock: 5508SN74AHC123ADR Datasheet

SimilarRFQ

SN74AHC123AMDREP

Texas InstrumentsIn Stock: 3309SN74AHC123AMDREP Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 74VHC123ASJ is determined by the following critical parameters: logic type (monostable multivibrator), independent circuit count (2), supply voltage compatibility (2 V ~ 5.5 V), package type (16-SOIC surface mount), and functional pin compatibility. All substitute parts must operate within the specified voltage range and maintain the dual-circuit architecture. Propagation delay, output current capability, operating temperature range, and Schmitt trigger input presence are secondary parameters that may vary between substitutes while maintaining functional equivalence. Package width variations (0.154" vs 0.209") are acceptable within the 16-SOIC family for PCB layout compatibility.

Parameter Comparison

Engineering Selection Recommendations

Direct Substitute (Highest Compatibility): SN74LV123ANSR maintains the original 16-SOIC (0.209", 5.30mm) package width, identical supply voltage range, and Schmitt trigger input functionality. This part is manufactured by Texas Instruments with active product status and ROHS3 compliance. The 13 ns propagation delay represents a 60% increase over the original 8.1 ns specification but remains within acceptable timing margins for most monostable multivibrator applications.

Primary Alternative (Recommended for New Designs): SN74AHC123ADR offers the fastest propagation delay at 7.5 ns, closest to the original 8.1 ns specification, with active product status and ROHS3 compliance. This part features Schmitt trigger input and operates across the full -40°C ~ 85°C temperature range. The 16-SOIC (0.154", 3.90mm) package width requires PCB layout verification but is mechanically compatible with standard 16-SOIC footprints.

Extended Temperature Range Option: SN74AHC123AMDREP extends the operating temperature range to -55°C ~ 125°C, suitable for industrial and automotive applications. This part maintains 7.5 ns propagation delay, Schmitt trigger input, and ROHS3 compliance with active product status.

Alternative with Faster Timing: 74AHC123AD,118 (Nexperia) provides the fastest propagation delay at 5.1 ns but lacks Schmitt trigger input functionality. This part is suitable only for applications where Schmitt trigger input is not required. ROHS3 compliance and active product status are confirmed.

All substitute parts maintain the dual independent circuit architecture, 2 V ~ 5.5 V supply voltage compatibility, and 8 mA output current capability (or higher) required for functional equivalence with the 74VHC123ASJ.

Frequently Asked Questions (FAQ)

Q: Can I use SN74LV123ANSR as a direct replacement for 74VHC123ASJ? A: Yes. SN74LV123ANSR maintains the same 16-SOIC (0.209", 5.30mm) package width, supply voltage range (2 V ~ 5.5 V), dual independent circuits, and Schmitt trigger input. The 13 ns propagation delay is slower than the original 8.1 ns but is functionally compatible for most applications. Verify timing-critical paths in your design before implementation.

Q: What is the difference between the 16-SOIC (0.209") and 16-SOIC (0.154") packages? A: Both are 16-pin SOIC packages with identical pin pitch and electrical compatibility. The difference is package width: 0.209" (5.30mm) versus 0.154" (3.90mm). Standard 16-SOIC PCB footprints accommodate both widths. Verify your PCB layout allows the narrower package if selecting a 0.154" variant.

Q: Why does 74AHC123AD,118 lack Schmitt trigger input? A: The 74AHC123AD,118 is a variant within the 74AHC series that omits Schmitt trigger input functionality. Use this part only if your application does not require Schmitt trigger input for noise immunity or signal conditioning.

Q: Which substitute offers the best propagation delay performance? A: 74AHC123AD,118 (Nexperia) provides the fastest propagation delay at 5.1 ns. If Schmitt trigger input is required, SN74AHC123ADR and SN74AHC123AMDREP both offer 7.5 ns propagation delay, closest to the original 8.1 ns specification.

Q: Are all substitute parts RoHS compliant? A: Yes. All substitute parts listed are ROHS3 compliant. The original 74VHC123ASJ RoHS status was not specified in the provided data.

Q: What is the inventory status of these substitute parts? A: SN74LV123ANSR: 3200 pcs; 74AHC123AD,118: 6759 pcs; SN74AHC123AD: 1900 pcs; SN74AHC123ADR: 5433 pcs; SN74AHC123AMDREP: 3225 pcs. All parts are listed as new original stock.