MM74HC161N Equivalent & Substitute Parts

Part Overview

The MM74HC161N is a 4-bit binary counter IC manufactured by onsemi, housed in a 16-DIP package. This component functions as a synchronous counter with asynchronous reset, designed for digital logic applications requiring counting operations at frequencies up to 40 MHz. The part is currently classified as obsolete, making equivalent substitutes necessary for ongoing production and maintenance applications. Direct replacements and functionally similar alternatives are available from active manufacturers.

Substiute Parts

MM74HC161N

onsemiIn Stock: 2709MM74HC161N Datasheet

Current PartRFQ

SN74HC161N

Texas InstrumentsIn Stock: 13734SN74HC161N Datasheet

DirectRFQ

CD74HC161E

Harris CorporationIn Stock: 2299CD74HC161E Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MM74HC161N is determined by the following critical parameters:

• Logic Type & Function: Must be a binary counter with identical counting direction (up)
• Bit Configuration: Must have 4 bits per element with 1 element
• Reset & Timing: Must feature asynchronous reset with synchronous timing operation
• Trigger Mechanism: Must respond to positive edge triggers
• Electrical Specifications: Must operate within the 2 V ~ 6 V supply range
• Package Compatibility: Must use 16-DIP (0.300", 7.62mm) through-hole mounting

The identified substitutes meet all these core functional and mechanical requirements, enabling direct replacement in circuit designs.

Parameter Comparison

Engineering Selection Recommendations

SN74HC161N (Texas Instruments) is the primary substitute for the MM74HC161N. This part is currently in active production status, ensuring long-term availability and supply chain reliability. It maintains full functional equivalence across all critical parameters. The operating temperature range is narrower (-40°C ~ 85°C versus -55°C ~ 125°C), and the maximum count rate is specified at 36 MHz compared to 40 MHz. These differences are acceptable for most applications operating within standard industrial temperature ranges and moderate frequency requirements. RoHS3 compliance provides environmental and regulatory advantages for new designs.

CD74HC161E (Harris Corporation) serves as an alternative substitute where extended temperature operation (-55°C ~ 125°C) is required. This part matches the original MM74HC161N temperature specification. However, the maximum count rate is limited to 24 MHz, which may restrict use in higher-frequency applications. The part is obsolete, presenting potential future availability constraints. RoHS non-compliance may limit applicability in regulated markets.

For new designs and ongoing production, SN74HC161N is the recommended choice due to active status and compliance certifications. CD74HC161E is suitable only when extended temperature range is a mandatory requirement and lower frequency operation is acceptable.

Frequently Asked Questions (FAQ)

Q: Can SN74HC161N directly replace MM74HC161N in existing designs?

A: Yes. Both parts share identical logic function, bit configuration, reset mechanism, trigger type, supply voltage range, and 16-DIP package. The SN74HC161N operates at 36 MHz maximum versus 40 MHz for the MM74HC161N, and has a narrower temperature range (-40°C ~ 85°C versus -55°C ~ 125°C). These differences are compatible with standard industrial applications.

Q: What is the primary difference between SN74HC161N and CD74HC161E?

A: The SN74HC161N is in active production with RoHS3 compliance, while CD74HC161E is obsolete and RoHS non-compliant. The SN74HC161N supports 36 MHz operation; CD74HC161E is limited to 24 MHz. The CD74HC161E maintains the extended temperature range (-55°C ~ 125°C) of the original MM74HC161N.

Q: Are all three parts mechanically interchangeable?

A: Yes. All three parts use the 16-DIP (0.300", 7.62mm) through-hole package, enabling direct socket replacement without PCB modifications.

Q: Which substitute should be selected for applications requiring extended temperature operation?

A: CD74HC161E maintains the -55°C ~ 125°C operating range. However, verify that the 24 MHz maximum count rate meets application frequency requirements before selection.

Q: Is the count rate difference between MM74HC161N (40 MHz) and SN74HC161N (36 MHz) significant?

A: The 4 MHz difference represents a 10% reduction in maximum frequency. For applications operating below 36 MHz, this difference is not functionally significant. Applications requiring operation above 36 MHz must use the original MM74HC161N or verify compatibility with the lower specification.