DM74LS161AM Equivalent & Substitute Parts

Part Overview

The DM74LS161AM is a 4-bit binary counter IC manufactured by onsemi in a 16-SOIC surface mount package. This component functions as a synchronous counter with asynchronous reset, positive edge triggering, and operates within the 4.75V to 5.25V supply voltage range. The part is classified as obsolete, making equivalent substitutes necessary for ongoing production and maintenance applications where this logic function is required.

Substiute Parts

DM74LS161AM

onsemiIn Stock: 1346DM74LS161AM Datasheet

Current PartRFQ

SN74LS161AD

onsemiIn Stock: 3967SN74LS161AD Datasheet

DirectRFQ

SN74LS161ADR

Texas InstrumentsIn Stock: 10258SN74LS161ADR Datasheet

DirectRFQ

SN74LS161ANSR

Texas InstrumentsIn Stock: 3033SN74LS161ANSR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the DM74LS161AM is determined by strict equivalence across the following critical parameters:

• 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
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Series: 74LS

All identified substitute parts maintain these core electrical and functional specifications. Variations in packaging format (Tube vs. Tape & Reel) and minor package dimensions do not affect functional equivalence. Product status differences (Obsolete vs. Active) and compliance certifications are noted for procurement and regulatory considerations.

Parameter Comparison

Engineering Selection Recommendations

For new designs and ongoing production, SN74LS161ADR (Texas Instruments) is the preferred substitute. This part maintains active product status, carries ROHS3 compliance certification, and is available in high volume (10,200 pcs in stock). The identical 16-SOIC package footprint (0.154", 3.90mm width) ensures direct PCB compatibility without layout modifications.

SN74LS161ANSR (Texas Instruments) provides an alternative with equivalent electrical performance and ROHS3 compliance. The wider 16-SO package (0.209", 5.30mm) requires PCB footprint verification before selection.

SN74LS161AD (onsemi) maintains manufacturer continuity but carries RoHS non-compliance status and obsolete product classification, limiting its suitability for new applications subject to regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can SN74LS161ADR directly replace DM74LS161AM on existing PCBs?

A: Yes. Both parts use identical 16-SOIC packaging with matching pin configurations, supply voltage ranges (4.75V–5.25V), and functional specifications. No circuit modifications are required.

Q: What is the difference between SN74LS161ADR and SN74LS161ANSR?

A: Both are functionally equivalent 4-bit binary counters from Texas Instruments with active product status. The primary difference is package width: SN74LS161ADR uses 0.154" (3.90mm) width, while SN74LS161ANSR uses 0.209" (5.30mm) width. PCB footprint compatibility must be confirmed before substitution.

Q: Why is DM74LS161AM classified as obsolete?

A: Obsolete status indicates the manufacturer has discontinued production. Active alternatives from Texas Instruments (SN74LS161ADR, SN74LS161ANSR) are available for new designs and replacement applications.

Q: Are there RoHS compliance differences between substitutes?

A: Yes. SN74LS161ADR and SN74LS161ANSR are ROHS3 compliant. SN74LS161AD is RoHS non-compliant. For applications requiring RoHS certification, select SN74LS161ADR or SN74LS161ANSR.

Q: What is the count rate specification for these parts?

A: SN74LS161AD, SN74LS161ADR, and SN74LS161ANSR all support a 25 MHz count rate, enabling high-frequency counting applications within the 74LS logic family specifications.