CD74AC161M Binary Counter 4-Bit Logic IC Equivalent & Substitute Parts

Part Overview

The CD74AC161M is a 4-bit binary counter logic IC manufactured by Texas Instruments in a 16-SOIC surface mount package. This component functions as a synchronous counter with asynchronous reset, designed for positive edge triggering applications. The part is currently discontinued at DiGi Electronics, making equivalent substitute parts necessary for ongoing production and maintenance applications.

Substiute Parts

CD74AC161M

Texas InstrumentsIn Stock: 1569CD74AC161M Datasheet

Current PartRFQ

MC74AC161DG

onsemiIn Stock: 2240MC74AC161DG Datasheet

DirectRFQ

MC74AC161DR2G

onsemiIn Stock: 10085MC74AC161DR2G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the CD74AC161M are qualified based on the following electrical and mechanical parameters:

Core Functional Parameters (Must Match):

• Logic Type: Binary Counter
• Number of Bits per Element: 4
• Number of Elements: 1
• Direction: Up
• Reset Type: Asynchronous
• Timing: Synchronous
• Trigger Type: Positive Edge
• Package / Case: 16-SOIC (0.154", 3.90mm Width)
• Mounting Type: Surface Mount
• Series: 74AC

Allowed Variation Parameters:

• Count Rate: May exceed original specification (90 MHz minimum)
• Voltage - Supply: May exceed original specification (1.5 V ~ 5.5 V minimum)
• Operating Temperature: May be narrower than original specification (-55°C ~ 125°C)

The substitute parts MC74AC161DG and MC74AC161DR2G, both manufactured by onsemi, meet all core functional requirements and maintain compatibility with the original CD74AC161M in equivalent circuit applications.

Parameter Comparison

Engineering Selection Recommendations

MC74AC161DR2G (onsemi) - Recommended Primary Substitute

The MC74AC161DR2G is the manufacturer-recommended substitute for the CD74AC161M. This part maintains full functional equivalence with identical logic specifications and package configuration. The onsemi part features enhanced performance characteristics with a count rate of 167 MHz compared to the original 90 MHz specification. The part is available in Cut Tape (CT) & Digi-Reel® packaging with 10,035 units in stock. Current product status is Last Time Buy, indicating ongoing availability for near-term procurement.

MC74AC161DG (onsemi) - Alternative Substitute

The MC74AC161DG provides equivalent functionality with identical electrical and logic specifications to the MC74AC161DR2G. This variant is supplied in Tube packaging and maintains the same 167 MHz count rate and supply voltage range. With 2,224 units in stock, this option is suitable for applications where tube packaging is acceptable.

Compliance and Regulatory Considerations

Both substitute parts maintain ROHS3 compliance, MSL Level 1 (Unlimited moisture sensitivity), and REACH Unaffected status, matching the original CD74AC161M specifications. All parts share the same ECCN (EAR99) and HTSUS (8542.39.0001) classifications.

Operating Environment Constraints

The onsemi substitutes operate within -40°C to 85°C temperature range, which is narrower than the original CD74AC161M specification of -55°C to 125°C. Applications requiring operation below -40°C or above 85°C require evaluation against specific design requirements.

Frequently Asked Questions (FAQ)

Q: Can MC74AC161DG and MC74AC161DR2G be used interchangeably with CD74AC161M?

A: Yes. Both onsemi parts are functionally equivalent to the CD74AC161M. The primary difference is packaging format: MC74AC161DR2G uses Cut Tape (CT) & Digi-Reel® packaging, while MC74AC161DG uses Tube packaging. The electrical and logic specifications are identical.

Q: What is the difference between MC74AC161DG and MC74AC161DR2G?

A: Both parts are electrically identical 4-bit binary counters with the same logic specifications and performance characteristics. The difference is packaging: MC74AC161DR2G is supplied on Cut Tape (CT) & Digi-Reel®, while MC74AC161DG is supplied in Tube format. Selection depends on assembly process requirements and inventory management preferences.

Q: Are the onsemi substitutes pin-compatible with the CD74AC161M?

A: Yes. All three parts use the 16-SOIC package with identical pinout and mechanical dimensions (0.154", 3.90mm Width). Direct board-level substitution is possible without layout modifications.

Q: What are the performance differences between CD74AC161M and the onsemi substitutes?

A: The onsemi parts (MC74AC161DG and MC74AC161DR2G) feature a higher count rate of 167 MHz compared to the CD74AC161M specification of 90 MHz. Both maintain the same 4-bit binary counter functionality, asynchronous reset, and synchronous timing. The supply voltage range for onsemi parts is 2 V ~ 6 V versus 1.5 V ~ 5.5 V for the original part.

Q: Are there temperature range limitations with the substitute parts?

A: The onsemi substitutes operate within -40°C to 85°C, which is narrower than the CD74AC161M range of -55°C to 125°C. Applications requiring operation at temperatures below -40°C or above 85°C must be evaluated against specific design requirements. For standard industrial and commercial temperature ranges, the substitutes are fully compatible.

Q: Do the substitute parts meet the same compliance standards?

A: Yes. Both MC74AC161DG and MC74AC161DR2G maintain ROHS3 compliance, MSL Level 1 (Unlimited), and REACH Unaffected status, matching the original CD74AC161M. All parts share identical ECCN and HTSUS classifications.

Q: Which substitute should be selected for new designs?

A: MC74AC161DR2G is the manufacturer-recommended substitute and is preferred for new designs due to higher inventory availability (10,035 units) and standard Cut Tape & Digi-Reel® packaging format compatible with automated assembly processes.