SN74LS393D Equivalent & Substitute Parts

Part Overview

The SN74LS393D is a binary counter IC manufactured by Texas Instruments, featuring two independent 4-bit counters with negative edge triggering. This component is classified as Last Time Buy, indicating discontinued production with limited availability. The SN74LS393D is housed in a 14-SOIC surface mount package and operates within the standard TTL voltage range of 4.75V to 5.25V. Due to its Last Time Buy status, identifying functionally equivalent substitute parts is essential for ongoing design support and production continuity.

Substiute Parts

SN74LS393D

Texas InstrumentsIn Stock: 1935SN74LS393D Datasheet

Current PartRFQ

SN74LS393DR

Texas InstrumentsIn Stock: 2122SN74LS393DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74LS393D is determined by strict equivalence across the following critical parameters:

• Logic Type: Binary Counter (2 Element, 4 Bit configuration)
• Trigger Type: Negative Edge
• Count Rate: 35 MHz minimum
• Voltage Supply Range: 4.75V ~ 5.25V
• Package Type: 14-SOIC surface mount
• Reset Function: Asynchronous
• Operating Temperature Range: 0°C ~ 70°C

The SN74LS393DR qualifies as a direct substitute based on identical electrical specifications and package configuration. The primary distinction between these parts is packaging format: the SN74LS393D is supplied in Tube packaging, while the SN74LS393DR is supplied in Tape & Reel (TR) format. Both parts maintain identical functional performance, pin configuration, and electrical characteristics.

Parameter Comparison

Engineering Selection Recommendations

The SN74LS393DR is the direct functional equivalent of the SN74LS393D. Both parts are manufactured by Texas Instruments and maintain identical electrical specifications, pin configurations, and performance characteristics. The SN74LS393DR carries Active product status, ensuring continued availability and supply chain stability compared to the Last Time Buy status of the SN74LS393D.

Both parts satisfy ROHS3 compliance and REACH unaffected requirements. The selection between these parts should be based on packaging requirements: Tube format for the SN74LS393D or Tape & Reel format for the SN74LS393DR. Tape & Reel packaging is standard for automated assembly processes, while Tube packaging is suitable for manual handling and lower-volume applications.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS393DR directly replace the SN74LS393D in existing designs?

A: Yes. The SN74LS393DR is electrically and functionally identical to the SN74LS393D. Both parts feature the same pin configuration, electrical specifications, and 14-SOIC package dimensions. No circuit modifications are required for substitution.

Q: What is the difference between Tube and Tape & Reel packaging?

A: Tube packaging supplies components in plastic tubes suitable for manual handling and small-quantity applications. Tape & Reel packaging supplies components on continuous carrier tape wound on reels, optimized for automated pick-and-place assembly equipment. Both formats contain identical components with identical performance.

Q: Why is the SN74LS393D marked as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments has discontinued production of this part number. Existing inventory may be available, but no new production runs are planned. The SN74LS393DR, with Active status, represents the current production equivalent and is recommended for new designs and long-term supply assurance.

Q: Are there any compliance or certification differences between these parts?

A: No. Both the SN74LS393D and SN74LS393DR maintain identical RoHS3 compliance, REACH unaffected status, and Moisture Sensitivity Level 1 (Unlimited) ratings.

Q: What is the maximum count rate for these binary counters?

A: Both parts support a maximum count rate of 35 MHz, determined by the negative edge trigger configuration and internal propagation delays of the 74LS logic family.