SN74LS648NT Equivalent & Substitute Parts

Part Overview

The SN74LS648NT is a Logic Transceiver, Inverting component manufactured by Texas Instruments in the 74LS series. This device functions as a 1 Element, 8 Bit per Element transceiver with 3-State output capability, housed in a 24-PDIP through-hole package. The product is classified as Obsolete, making identification of functionally equivalent alternatives necessary for ongoing design support and component procurement in legacy systems or new designs requiring this specific logic function.

Substiute Parts

SN74LS648NT

Texas InstrumentsIn Stock: 4570SN74LS648NT Datasheet

Current PartRFQ

SN74ALS648ADW

Texas InstrumentsIn Stock: 1025SN74ALS648ADW Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74LS648NT is determined by the following critical parameters:

• Logic Function: Transceiver, Inverting configuration with 1 Element and 8 Bits per Element
• Output Characteristics: 3-State output with matching current specifications (15mA high, 24mA low)
• Electrical Performance: Supply voltage range and operating temperature compatibility
• Package Compatibility: Physical form factor and pin configuration

The SN74ALS648ADW qualifies as a manufacturer-recommended substitute based on identical logic function, element count, bit configuration, output type, and current ratings. The primary differences are the product series (74ALS vs. 74LS), supply voltage range (4.5V ~ 5.5V vs. 4.75V ~ 5.25V), package form factor (24-SOIC surface mount vs. 24-DIP through hole), and product status (Active vs. Obsolete).

Parameter Comparison

Engineering Selection Recommendations

The SN74ALS648ADW is the manufacturer-recommended substitute for the SN74LS648NT. Both components maintain identical logic function, element configuration, bit width, output type, and current specifications. The 74ALS series represents an advanced low-power variant of the 74LS logic family, offering improved electrical performance characteristics.

Selection of the SN74ALS648ADW requires consideration of mounting technology compatibility. The substitute employs surface-mount packaging (24-SOIC) in contrast to the through-hole configuration (24-DIP) of the original part. This necessitates corresponding changes to printed circuit board layout and assembly processes.

Both components are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements. The SN74ALS648ADW carries Active product status, ensuring continued availability and manufacturing support.

Frequently Asked Questions (FAQ)

Q: Can the SN74ALS648ADW directly replace the SN74LS648NT in existing designs?

A: Functional substitution is valid based on identical logic specifications. However, the package form factor differs: the SN74LS648NT uses 24-DIP through-hole mounting while the SN74ALS648ADW uses 24-SOIC surface-mount packaging. PCB redesign is required for physical implementation.

Q: What are the key electrical differences between these parts?

A: The supply voltage range differs slightly: SN74LS648NT operates at 4.75V ~ 5.25V, while SN74ALS648ADW operates at 4.5V ~ 5.5V. Both maintain identical output current specifications (15mA high, 24mA low) and operating temperature range (0°C ~ 70°C).

Q: Why is the SN74LS648NT classified as Obsolete?

A: The 74LS logic family represents an earlier generation technology. The 74ALS series provides equivalent functionality with improved performance characteristics and continues to receive manufacturing support.

Q: Are there any compliance or certification differences?

A: Both components are ROHS3 compliant and REACH unaffected. No compliance or certification differences exist between the two parts.

Q: What inventory status should be considered for procurement?

A: The SN74LS648NT shows 4467 pieces in stock as new original inventory. The SN74ALS648ADW shows 976 pieces in stock. Availability should be verified with your component supplier for current procurement timelines.