74FST3126DR2 Equivalent & Substitute Parts

Part Overview

The 74FST3126DR2 is a bus switch IC manufactured by onsemi, designed for 1 x 1:1 switching applications with 4 independent circuits. This component operates on a single supply voltage between 4V and 5.5V and is housed in a 14-SOIC surface mount package. The part is currently classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and production continuity.

Substiute Parts

74FST3126DR2

onsemiIn Stock: 116174FST3126DR2 Datasheet

Current PartRFQ

SN74CBT3126D

Texas InstrumentsIn Stock: 3671SN74CBT3126D Datasheet

DirectRFQ

SN74CBT3126DR

Texas InstrumentsIn Stock: 3573SN74CBT3126DR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 74FST3126DR2 are qualified based on the following critical parameters that determine functional equivalence:

• Circuit configuration: 1 x 1:1 topology with 4 independent circuits
• Package type: 14-SOIC surface mount housing with identical 0.154" (3.90mm) width
• Voltage supply range: Single supply operation
• Operating temperature range: -40°C ~ 85°C
• Mounting type: Surface mount

The identified substitutes are the SN74CBT3126D and SN74CBT3126DR, both manufactured by Texas Instruments. These parts maintain identical circuit topology, package specifications, and thermal operating ranges. Both substitutes are available in the same 14-SOIC package and support the same voltage supply architecture.

Parameter Comparison

Engineering Selection Recommendations

The SN74CBT3126D and SN74CBT3126DR are direct functional equivalents to the 74FST3126DR2. Both Texas Instruments substitutes maintain identical circuit topology, package footprint, and thermal specifications. The primary differences are:

Voltage Supply Range: The substitute parts specify a minimum supply voltage of 4.5V compared to the original part's 4V minimum. Designs operating at voltages below 4.5V require validation against the original 74FST3126DR2 datasheet specifications.

RoHS Compliance: Both substitute parts are ROHS3 compliant, whereas the original 74FST3126DR2 is RoHS non-compliant. This compliance improvement may be advantageous for new designs or applications with regulatory requirements.

Product Status: Both substitutes are classified as Last Time Buy, indicating limited future availability. Long-term production designs should evaluate alternative architectures or secure adequate inventory.

Packaging Options: The SN74CBT3126D is supplied in Tube packaging, while the SN74CBT3126DR is supplied in Tape & Reel format. Selection depends on assembly process requirements and volume specifications.

Frequently Asked Questions (FAQ)

Q: Can the SN74CBT3126D and SN74CBT3126DR be used interchangeably with the 74FST3126DR2?

A: Yes, both Texas Instruments parts are functionally equivalent. The primary difference is packaging format: Tube versus Tape & Reel. The electrical specifications and pin configurations are identical.

Q: What is the impact of the 4.5V minimum supply voltage on the SN74CBT3126 substitutes?

A: The original 74FST3126DR2 operates at 4V minimum, while the substitutes require 4.5V minimum. If your design operates below 4.5V, the substitutes are not compatible without circuit modification or voltage regulation adjustment.

Q: Are the substitute parts pin-compatible with the original 74FST3126DR2?

A: Yes. All three parts use the identical 14-SOIC package with the same pin configuration and footprint dimensions (0.154" width, 3.90mm).

Q: What does "Last Time Buy" status mean for the substitute parts?

A: Last Time Buy indicates that the manufacturer will no longer produce these parts after a specified date. Existing inventory may be available, but long-term availability is not guaranteed. Designs should plan for alternative solutions or secure adequate stock.

Q: Does the ROHS3 compliance of the substitute parts affect compatibility?

A: No. ROHS3 compliance is a material composition specification that does not affect electrical or mechanical compatibility. It may be beneficial for applications with environmental or regulatory requirements.

Q: Which substitute part should I select for high-volume production?

A: Selection depends on your assembly process. The SN74CBT3126D (Tube) is suitable for lower-volume or manual assembly. The SN74CBT3126DR (Tape & Reel) is optimized for automated pick-and-place assembly at higher volumes.