74ACT161SCX Binary Counter IC Equivalent & Substitute Parts

Part Overview

The 74ACT161SCX is a 4-bit binary counter IC manufactured by onsemi, housed in a 16-SOIC surface mount package. This component functions as a synchronous counter with asynchronous reset, operating at a maximum count rate of 125 MHz. The part is currently classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity.

Substiute Parts

74ACT161SCX

onsemiIn Stock: 366174ACT161SCX Datasheet

Current PartRFQ

MC74ACT161DR2G

onsemiIn Stock: 2975MC74ACT161DR2G Datasheet

DirectRFQ

MC74ACT161DG

onsemiIn Stock: 1928MC74ACT161DG Datasheet

SimilarRFQ

CD74ACT161M

Harris CorporationIn Stock: 5840CD74ACT161M Datasheet

SimilarRFQ

CD74ACT161M96

Texas InstrumentsIn Stock: 4021CD74ACT161M96 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74ACT161SCX is determined by strict equivalence across the following critical parameters:

• Logic Type: Binary Counter (4-bit, up-counting)
• Reset Configuration: Asynchronous reset capability
• Timing Architecture: Synchronous operation
• Trigger Mechanism: Positive edge triggering
• Supply Voltage Range: 4.5 V ~ 5.5 V compatibility
• Package Form Factor: 16-SOIC surface mount package
• Pin Configuration: Identical pinout as base product number 74ACT161

All substitute parts listed maintain these core functional and physical characteristics, ensuring direct replacement capability without circuit redesign.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: CD74ACT161M96 (Texas Instruments)

The CD74ACT161M96 is the recommended substitute for new designs and production continuity. This part maintains full functional equivalence with the 74ACT161SCX across all critical parameters. The CD74ACT161M96 carries Active product status, ensuring long-term availability and supply chain stability. It is ROHS3 compliant and carries REACH Unaffected certification, meeting modern regulatory requirements. The extended operating temperature range (-55°C ~ 125°C) provides additional thermal margin compared to the original part.

Secondary Substitutes: MC74ACT161DR2G and MC74ACT161DG (onsemi)

Both onsemi alternatives maintain identical functional specifications to the 74ACT161SCX, including the 125 MHz count rate. MC74ACT161DR2G is supplied in Cut Tape packaging, while MC74ACT161DG is supplied in Tube packaging. Both carry Last Time Buy status and ROHS3 compliance. These parts are suitable for applications requiring the higher 125 MHz performance specification.

Alternative Substitute: CD74ACT161M (Harris Corporation)

The CD74ACT161M provides functional equivalence with a reduced count rate of 80 MHz. This part is classified as obsolete and RoHS non-compliant. Selection of this part is appropriate only for legacy system maintenance where the 80 MHz specification is acceptable and regulatory compliance is not required.

Frequently Asked Questions (FAQ)

Q: Can the MC74ACT161DR2G replace the 74ACT161SCX directly?

A: Yes. The MC74ACT161DR2G maintains identical functional specifications, package form factor, and pinout. The only differences are packaging format (Cut Tape versus unspecified) and product status (Last Time Buy versus Obsolete). Direct substitution is possible without circuit modification.

Q: What is the significance of the 125 MHz versus 80 MHz count rate difference?

A: The count rate specifies the maximum frequency at which the counter can reliably operate. The 74ACT161SCX, MC74ACT161DR2G, and MC74ACT161DG support 125 MHz operation. The CD74ACT161M and CD74ACT161M96 support 80 MHz operation. Applications requiring operation above 80 MHz must use parts rated for 125 MHz.

Q: Are all substitute parts RoHS compliant?

A: No. The CD74ACT161M (Harris) is RoHS non-compliant. The MC74ACT161DR2G, MC74ACT161DG, and CD74ACT161M96 are ROHS3 compliant. For applications subject to RoHS regulations, select only ROHS3 compliant alternatives.

Q: What is the difference between Cut Tape and Tube packaging?

A: Cut Tape (CT) and Tube packaging are different supply formats for surface mount components. Both formats contain identical die and are functionally equivalent. Packaging selection depends on assembly equipment compatibility and inventory management preferences. The MC74ACT161DR2G (Cut Tape) and MC74ACT161DG (Tube) are otherwise identical.

Q: Can I use CD74ACT161M96 in applications designed for the 74ACT161SCX?

A: Yes. The CD74ACT161M96 is fully compatible. It provides superior specifications including Active product status, extended temperature range (-55°C ~ 125°C), and ROHS3 compliance. The 80 MHz count rate specification is lower than the original 125 MHz, but this does not prevent substitution in applications operating at or below 80 MHz.

Q: Why is the 74ACT161SCX classified as obsolete?

A: Obsolete status indicates the manufacturer has discontinued production and will not accept new orders. This classification necessitates the use of equivalent or substitute parts for ongoing production and design support. Active alternatives such as CD74ACT161M96 ensure continued availability.