74AC161SCX Binary Counter 4-Bit Logic IC Equivalent & Substitute Parts

Part Overview

The 74AC161SCX is a 4-bit binary counter logic IC manufactured by onsemi, housed in a 16-SOIC surface mount package. This component functions as a synchronous binary counter with asynchronous reset, capable of counting on positive clock edges at up to 167 MHz. The part is currently listed as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Substiute Parts

74AC161SCX

onsemiIn Stock: 479574AC161SCX Datasheet

Current PartRFQ

MC74AC161DR2G

onsemiIn Stock: 10085MC74AC161DR2G Datasheet

DirectRFQ

MC74AC161DG

onsemiIn Stock: 2240MC74AC161DG Datasheet

SimilarRFQ

CD74AC161M

Texas InstrumentsIn Stock: 1569CD74AC161M Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 74AC161SCX is determined by the following critical parameters:

• Logic Function: Binary counter, 4-bit, positive edge triggered
• Package Compatibility: 16-SOIC surface mount form factor
• Electrical Specifications: Supply voltage range, count rate, operating temperature
• Reset Mechanism: Asynchronous reset capability
• Timing Architecture: Synchronous counting operation

Substitute parts must maintain identical or superior electrical performance within the specified parameter ranges. Parts are grouped into two categories: direct manufacturer equivalents from onsemi and cross-manufacturer alternatives from Texas Instruments.

Parameter Comparison

Engineering Selection Recommendations

MC74AC161DR2G (onsemi) is the primary direct substitute. This part maintains identical electrical specifications to the 74AC161SCX, including 167 MHz count rate and 2 V ~ 6 V supply voltage range. The MC74AC161DR2G carries Last Time Buy status with higher inventory availability (10,035 units) and is ROHS3 compliant. Packaging is specified as Cut Tape (CT) & Digi-Reel®, suitable for automated assembly processes.

MC74AC161DG (onsemi) is a secondary onsemi equivalent with identical electrical performance. This variant is supplied in Tube packaging and also maintains Last Time Buy status. Inventory is lower (2,224 units) compared to the DR2G variant.

CD74AC161M (Texas Instruments) is a cross-manufacturer alternative. While it maintains the same 4-bit binary counter function and 16-SOIC package, the count rate is reduced to 90 MHz and the supply voltage range is narrower (1.5 V ~ 5.5 V). The operating temperature range is extended (-55°C ~ 125°C). This part is discontinued at DiGi Electronics and should be considered only when the reduced count rate and narrower voltage range are acceptable for the application.

Frequently Asked Questions (FAQ)

Q: Can MC74AC161DR2G directly replace 74AC161SCX without circuit modification?

A: Yes. The MC74AC161DR2G maintains identical electrical specifications, package form factor, and pin configuration. No circuit modifications are required for direct substitution.

Q: What is the difference between MC74AC161DR2G and MC74AC161DG?

A: Both parts are electrically identical. The primary difference is packaging: MC74AC161DR2G is supplied in Cut Tape (CT) & Digi-Reel® format for automated pick-and-place assembly, while MC74AC161DG is supplied in Tube format for manual handling or lower-volume applications.

Q: Is CD74AC161M a suitable substitute if my application requires 167 MHz operation?

A: No. The CD74AC161M has a maximum count rate of 90 MHz, which is insufficient for applications requiring 167 MHz operation. Use MC74AC161DR2G or MC74AC161DG instead.

Q: Are all substitute parts ROHS3 compliant?

A: MC74AC161DR2G and MC74AC161DG are both ROHS3 compliant. The 74AC161SCX compliance status is not specified in available documentation.

Q: What is the inventory status of available substitutes?

A: MC74AC161DR2G has the highest availability (10,035 units in stock). MC74AC161DG has 2,224 units available. CD74AC161M has 1,550 units but is discontinued at DiGi Electronics and should not be relied upon for future procurement.

Q: Can I use CD74AC161M in a circuit designed for 2 V ~ 6 V supply operation?

A: The CD74AC161M supply voltage range is 1.5 V ~ 5.5 V. Circuits requiring operation above 5.5 V are not compatible with this part. Verify your supply voltage requirements before selecting this substitute.