MM74HC123AM Equivalent & Substitute Parts

Part Overview

The MM74HC123AM is a monostable multivibrator logic IC manufactured by onsemi, housed in a 16-SOIC package with a 22 ns propagation delay. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The 74HC123 series provides dual independent monostable circuits with Schmitt trigger inputs, suitable for timing and pulse generation applications across industrial and commercial electronics.

Substiute Parts

MM74HC123AM

onsemiIn Stock: 1368MM74HC123AM Datasheet

Current PartRFQ

74HC123D,653

Nexperia USA Inc.In Stock: 198674HC123D,653 Datasheet

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CD74HC123M96

Texas InstrumentsIn Stock: 50187CD74HC123M96 Datasheet

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CD74HC123ME4

Texas InstrumentsIn Stock: 969CD74HC123ME4 Datasheet

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CD74HC123MG4

Texas InstrumentsIn Stock: 920CD74HC123MG4 Datasheet

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CD74HC123MT

Texas InstrumentsIn Stock: 11170CD74HC123MT Datasheet

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CD74HC123NSR

Texas InstrumentsIn Stock: 3798CD74HC123NSR Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MM74HC123AM is determined by the following critical parameters:

• Base Product Number: All substitutes must belong to the 74HC123 series to ensure functional equivalence
• Logic Type: Monostable multivibrator with 2 independent circuits
• Package / Case: 16-SOIC or 16-SO surface mount packages with compatible pinouts
• Voltage Supply Range: 2 V to 6 V compatibility required
• Output Current: 5.2 mA minimum for both high and low states
• Mounting Type: Surface mount only

Substitutes are grouped into two categories based on propagation delay performance and product status:

Category 1 - Active Status (Preferred for New Designs)

• CD74HC123M96 (Texas Instruments, 25 ns, Active)
• CD74HC123NSR (Texas Instruments, 25 ns, Active)
• 74HC123D,653 (Nexperia USA Inc., 65 ns, Active)

Category 2 - Discontinued or Obsolete Status (Limited Availability)

• CD74HC123ME4 (Texas Instruments, 25 ns, Discontinued at DiGi Electronics)
• CD74HC123MG4 (Texas Instruments, 25 ns, Obsolete)
• CD74HC123MT (Texas Instruments, 25 ns, Discontinued at DiGi Electronics)

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Active Status)

CD74HC123M96 is the preferred substitute for new designs. It maintains the 16-SOIC (0.154", 3.90 mm) package footprint identical to the MM74HC123AM, offers improved propagation delay performance at 25 ns, and provides extended operating temperature range (-55°C to 125°C). ROHS3 compliance ensures regulatory alignment for current manufacturing standards. Texas Instruments maintains active production status with substantial inventory availability (50,100 pcs).

CD74HC123NSR provides equivalent electrical performance with active product status and ROHS3 compliance. The package width differs at 0.209" (5.30 mm) versus the original 0.154" (3.90 mm), requiring PCB layout verification before implementation. Texas Instruments maintains this part in active production (3,777 pcs available).

74HC123D,653 from Nexperia USA Inc. is functionally compatible with active product status and ROHS3 compliance. The 65 ns propagation delay is slower than the original 22 ns specification; timing-critical applications must account for this performance difference. This part is available in quantity (1,900 pcs).

Secondary Substitutes (Discontinued or Obsolete Status)

CD74HC123ME4, CD74HC123MG4, and CD74HC123MT are available in limited quantities but carry discontinued or obsolete designations. These parts are suitable only for legacy system maintenance or when primary substitutes are unavailable. All three maintain ROHS3 compliance and the 16-SOIC package format.

Frequently Asked Questions (FAQ)

Q: Can I directly replace MM74HC123AM with CD74HC123M96 without PCB modifications?

A: Yes. Both parts use the 16-SOIC (0.154", 3.90 mm) package with identical pinouts. No PCB layout changes are required. The 25 ns propagation delay of CD74HC123M96 is faster than the original 22 ns, which is functionally compatible for timing applications.

Q: What is the difference between CD74HC123NSR and CD74HC123M96?

A: Both are Texas Instruments 74HC123 monostable multivibrators with 25 ns propagation delay and identical electrical specifications. The primary difference is package width: CD74HC123NSR measures 0.209" (5.30 mm) while CD74HC123M96 measures 0.154" (3.90 mm). Verify PCB footprint compatibility before selection.

Q: Why does 74HC123D,653 have a longer propagation delay (65 ns)?

A: The Nexperia part operates at a different speed grade within the 74HC123 family. While functionally equivalent as a monostable multivibrator, the 65 ns delay is significantly slower than the original 22 ns. Applications with strict timing requirements must account for this performance difference or select faster alternatives.

Q: Are all substitute parts ROHS3 compliant?

A: All active and discontinued Texas Instruments parts (CD74HC123M96, CD74HC123NSR, CD74HC123ME4, CD74HC123MG4, CD74HC123MT) are ROHS3 compliant. The Nexperia part (74HC123D,653) is also ROHS3 compliant. The original MM74HC123AM does not specify RoHS status.

Q: Which substitute has the best long-term availability?

A: CD74HC123M96 from Texas Instruments is the recommended choice for long-term availability. It maintains active product status with the largest inventory (50,100 pcs), ensuring consistent procurement for ongoing production and design support.

Q: Can I use these substitutes in designs requiring Schmitt trigger inputs?

A: The original MM74HC123AM includes Schmitt trigger inputs. All substitute parts listed (CD74HC123M96, CD74HC123NSR, 74HC123D,653, CD74HC123ME4, CD74HC123MG4, CD74HC123MT) do not feature Schmitt trigger inputs. If Schmitt trigger functionality is critical to your application, alternative parts outside the 74HC123 family must be evaluated.