SN74LS03D NAND Gate IC Equivalent & Substitute Parts

Part Overview

The SN74LS03D is a 4-channel 2-input NAND gate logic IC manufactured by Texas Instruments in a 14-SOIC surface mount package. This component features open collector outputs and operates within the 4.75V to 5.25V supply voltage range, making it suitable for TTL logic applications requiring open collector functionality.

The SN74LS03D is classified as Last Time Buy, indicating limited availability from the original manufacturer. Identifying equivalent and substitute parts is necessary to ensure design continuity and secure component supply for production and maintenance applications.

Substiute Parts

SN74LS03D

Texas InstrumentsIn Stock: 1575SN74LS03D Datasheet

Current PartRFQ

SN74LS26D

MotorolaIn Stock: 8528SN74LS26D Datasheet

DirectRFQ

SN74LS38D

onsemiIn Stock: 43652SN74LS38D Datasheet

DirectRFQ

SN74LS03DR

Texas InstrumentsIn Stock: 3265SN74LS03DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SN74LS03D are identified based on the following critical parameters that determine functional and mechanical compatibility:

Core Substitution Criteria:

• Logic Type: NAND Gate (4 channels, 2 inputs per channel)
• Features: Open Collector output configuration
• Voltage - Supply: 4.75V ~ 5.25V range
• Input Logic Levels: Low 0.8V, High 2V
• Package / Case: 14-SOIC form factor
• Mounting Type: Surface Mount

The substitute parts listed below maintain these core electrical and mechanical specifications, ensuring pin-compatible operation within the same circuit topology. Variations in output current ratings and propagation delay characteristics are noted but do not prevent functional substitution when circuit design margins accommodate these differences.

Parameter Comparison

Engineering Selection Recommendations

SN74LS03DR (Manufacturer Recommended Substitute)

The SN74LS03DR is the preferred substitute for the SN74LS03D. Both parts are manufactured by Texas Instruments and share identical electrical specifications. The SN74LS03DR maintains Active product status and ROHS3 compliance, ensuring long-term availability and regulatory alignment. The primary difference is packaging format: SN74LS03DR is supplied in Tape & Reel (TR) configuration versus the Tube packaging of the SN74LS03D. This substitution is direct and requires no circuit design modifications.

SN74LS26D (Motorola Manufacture)

The SN74LS26D is functionally compatible with the SN74LS03D, maintaining identical logic configuration, supply voltage range, and propagation delay specifications. However, the output low current specification is reduced to 8mA compared to the 16mA of the main part. The SN74LS26D is classified as Obsolete and does not meet ROHS3 compliance. This part is suitable only when circuit design margins accommodate the lower output current and when RoHS compliance is not a requirement.

SN74LS38D (onsemi Manufacture)

The SN74LS38D maintains core NAND gate functionality and open collector configuration with identical supply voltage and input logic level specifications. The output low current is increased to 24mA, and the maximum load capacitance specification is 45pF compared to 15pF for the main part. The SN74LS38D is classified as Obsolete and does not meet ROHS3 compliance. This part is suitable when higher output current capability is required and when RoHS compliance is not a requirement.

Frequently Asked Questions (FAQ)

Q: Can SN74LS03DR be used as a direct replacement for SN74LS03D?

A: Yes. The SN74LS03DR is electrically and functionally identical to the SN74LS03D. Both are manufactured by Texas Instruments with matching electrical specifications. The difference is packaging format: SN74LS03DR uses Tape & Reel packaging while SN74LS03D uses Tube packaging. No circuit modifications are required.

Q: What is the difference between open collector output and standard CMOS output?

A: Open collector outputs require an external pull-up resistor to establish a high logic level. This configuration allows multiple open collector outputs to be wire-ORed together and provides flexibility in output voltage levels. The SN74LS03D, SN74LS03DR, SN74LS26D, and SN74LS38D all feature open collector outputs.

Q: Why does the SN74LS38D have a higher maximum load capacitance specification?

A: The SN74LS38D specifies a maximum load capacitance of 45pF compared to 15pF for the SN74LS03D. This parameter reflects the propagation delay measurement conditions and does not indicate superior performance. Circuit design should be based on actual load capacitance requirements rather than maximum specification values.

Q: Are the obsolete parts (SN74LS26D and SN74LS38D) still available for purchase?

A: Inventory availability for obsolete parts varies. The provided data indicates current stock levels for both parts. However, obsolete classification indicates that manufacturers have discontinued production, and future availability cannot be guaranteed. The SN74LS03DR is recommended for new designs due to its Active status.

Q: What does ROHS3 compliance mean?

A: ROHS3 compliance indicates the part meets the Restriction of Hazardous Substances Directive requirements, restricting the use of specific hazardous materials including lead, mercury, cadmium, and certain flame retardants. The SN74LS03D and SN74LS03DR are ROHS3 compliant, while SN74LS26D and SN74LS38D are not.

Q: Can I use SN74LS26D or SN74LS38D in applications requiring RoHS compliance?

A: No. SN74LS26D and SN74LS38D are classified as RoHS non-compliant. Applications requiring RoHS compliance must use SN74LS03D or SN74LS03DR.

Q: What is the significance of the 14-SOIC package specification?

A: The 14-SOIC (Small Outline Integrated Circuit) package is a surface mount form factor with 14 pins, 0.154 inches (3.90mm) width. All substitute parts use the same 14-SOIC package, ensuring mechanical and pin compatibility. No PCB layout modifications are required when substituting between these parts.