DM74AS21N Equivalent & Substitute Parts

Part Overview

The DM74AS21N is a 2-channel AND gate logic IC in 14-MDIP packaging manufactured by onsemi. This component implements dual 4-input AND gate functions and operates within the 4.5V to 5.5V supply voltage range. The product is currently classified as obsolete, making identification of compatible substitute parts essential for ongoing system support and component procurement.

Substiute Parts

DM74AS21N

onsemiIn Stock: 956DM74AS21N Datasheet

Current PartRFQ

SN74AS21N

Texas InstrumentsIn Stock: 1540SN74AS21N Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DM74AS21N is determined by strict equivalence across the following parameters:

• Logic function: 2-channel AND gate with 4 inputs per channel
• Electrical specifications: 4.5V to 5.5V supply voltage, 2mA/20mA output current, 0.8V/2V input logic levels, 6ns propagation delay at 5V with 50pF load
• Operating temperature range: 0°C to 70°C
• Physical form factor: 14-DIP through-hole package with 0.300" (7.62mm) pitch
• Base product series: 74AS logic family

The SN74AS21N from Texas Instruments meets all these criteria and is therefore a parametric equivalent. Both parts share identical electrical characteristics, logic function, and package specifications, with the primary distinction being manufacturer and product status.

Parameter Comparison

Engineering Selection Recommendations

The SN74AS21N is a direct parametric equivalent to the DM74AS21N. Selection between these parts should be based on the following factors:

• Product Status: The SN74AS21N maintains active product status with Texas Instruments, ensuring ongoing availability and support. The DM74AS21N is obsolete.
• Compliance: The SN74AS21N carries RoHS3 compliance certification, whereas the DM74AS21N does not specify RoHS status. Both parts are REACH Unaffected and classified as EAR99.
• Inventory Availability: The SN74AS21N has higher documented inventory levels (1445 Pcs) compared to the DM74AS21N (925 Pcs).
• Packaging: The SN74AS21N is supplied in tube packaging, while the DM74AS21N packaging format is not specified.

For new designs or system refreshes, the SN74AS21N is the preferred selection due to active product status and RoHS3 compliance.

Frequently Asked Questions (FAQ)

Q: Can the SN74AS21N directly replace the DM74AS21N in existing designs?

A: Yes. Both parts are parametric equivalents with identical electrical specifications, logic function, and 14-DIP package dimensions. Direct pin-for-pin substitution is supported without circuit modification.

Q: What is the difference between the DM74AS21N and SN74AS21N?

A: The primary differences are manufacturer (onsemi vs. Texas Instruments), product status (obsolete vs. active), and compliance certifications (RoHS3 for SN74AS21N). All electrical and functional parameters are identical.

Q: Why is the DM74AS21N listed as obsolete?

A: Obsolescence status indicates the manufacturer has discontinued active production and support. The SN74AS21N from Texas Instruments provides equivalent functionality with ongoing availability.

Q: Are there any package compatibility concerns?

A: Both parts use the 14-DIP (0.300", 7.62mm) through-hole package. Physical and electrical pin configurations are identical, ensuring direct compatibility on PCBs designed for either part.

Q: What compliance certifications apply to these parts?

A: Both parts are REACH Unaffected and classified as EAR99. The SN74AS21N additionally carries RoHS3 compliance certification.