SN54LS244J Equivalent & Substitute Parts

Part Overview

The SN54LS244J is a military-grade, non-inverting buffer IC manufactured by Texas Instruments, designed for applications requiring reliable signal buffering in harsh operating environments. This 20-pin CDIP package device operates across the 4.5V to 5.5V supply range and maintains functionality across the extended military temperature range of -55°C to 125°C. The device features 2 elements with 4 bits per element and 3-state output capability, making it suitable for bus-oriented applications requiring signal isolation and drive capability.

The SN54LS244J remains in active production status. Identifying equivalent substitute parts becomes necessary when addressing supply chain constraints, lead time requirements, or when design specifications permit operation within alternative electrical and thermal parameters.

Substiute Parts

SN54LS244J

Texas InstrumentsIn Stock: 7736SN54LS244J Datasheet

Current PartRFQ

CD74FCT541E

Texas InstrumentsIn Stock: 985CD74FCT541E Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN54LS244J is determined by the following critical parameters:

Functional Equivalence: Logic type (Buffer, Non-Inverting), output type (3-State), and total bit capacity must match or exceed the original specification.

Electrical Compatibility: Supply voltage range, output current drive capability, and input type characteristics must support the intended application circuit.

Environmental Suitability: Operating temperature range must encompass the application's thermal requirements. Military-grade operation (-55°C to 125°C) may be substituted with commercial-grade operation (0°C to 70°C) only when application thermal conditions permit.

Package Compatibility: Physical package dimensions and pin configuration must be compatible with the PCB layout and socket specifications.

Compliance Requirements: RoHS and REACH compliance status must meet regulatory and procurement requirements.

The CD74FCT541E qualifies as a substitute based on matching logic type, output type, 3-state capability, and package footprint compatibility, with the understanding that its operating temperature range and supply voltage specifications differ from the original part.

Parameter Comparison

Engineering Selection Recommendations

SN54LS244J Selection: Maintain this part number for applications requiring military-grade temperature operation (-55°C to 125°C) or when the specific 2-element, 4-bit configuration is functionally required. Both the SN54LS244J and CD74FCT541E maintain active production status and ROHS3 compliance.

CD74FCT541E Selection: This substitute is applicable when application operating temperature remains within the 0°C to 70°C range and when the 1-element, 8-bit configuration meets or exceeds functional requirements. The CD74FCT541E provides higher output current drive capability (15mA high, 64mA low) compared to the SN54LS244J (12mA, 12mA), which may benefit applications requiring increased fan-out or lower impedance drive. Both devices maintain identical RoHS3 compliance status.

Supply Voltage Consideration: The CD74FCT541E operates within 4.75V to 5.25V, which represents a narrower range than the SN54LS244J (4.5V to 5.5V). Verify that the application power supply remains within the 4.75V to 5.25V window when selecting the CD74FCT541E.

Frequently Asked Questions (FAQ)

Q: Can the CD74FCT541E directly replace the SN54LS244J in all applications?

A: Direct replacement is possible only when the application operating temperature remains within 0°C to 70°C and the supply voltage remains within 4.75V to 5.25V. The CD74FCT541E is not suitable for military-grade temperature applications requiring -55°C operation.

Q: What is the functional difference between the 2-element, 4-bit configuration of the SN54LS244J and the 1-element, 8-bit configuration of the CD74FCT541E?

A: Both configurations provide 8 total bits of buffering with 3-state output capability. The SN54LS244J organizes these as two independent 4-bit buffers, while the CD74FCT541E provides a single 8-bit buffer. Pin configuration and control logic differ between the two devices; PCB layout and firmware control logic must be verified for compatibility.

Q: Are the package dimensions identical between the SN54LS244J and CD74FCT541E?

A: Both devices use 20-pin DIP packages with 0.300" (7.62mm) row spacing, making them physically compatible for through-hole PCB mounting. However, the SN54LS244J uses CDIP (ceramic) packaging while the CD74FCT541E uses PDIP (plastic) packaging. Verify that the application environment permits plastic packaging before substitution.

Q: What are the output current differences, and how do they affect circuit design?

A: The SN54LS244J provides 12mA output current (both high and low states). The CD74FCT541E provides 15mA high and 64mA low output current. The higher low-state current of the CD74FCT541E may reduce propagation delay and improve noise margins in applications with significant capacitive loading, but does not require circuit redesign for standard TTL/CMOS logic interfaces.

Q: Are both parts compliant with current regulatory requirements?

A: Both the SN54LS244J and CD74FCT541E are ROHS3 compliant and REACH unaffected, meeting current regulatory requirements for commercial and industrial applications.