FST3126M Equivalent & Substitute Parts

Part Overview

The FST3126M is a Bus Switch IC in 1 x 1:1 configuration, manufactured by onsemi in 14-SOIC surface mount packaging. This component functions as a logic-level bus switch for signal routing and isolation applications. The FST3126M carries an Obsolete product status, making identification of functionally equivalent alternatives essential for ongoing design support and procurement planning.

Substiute Parts

FST3126M

onsemiIn Stock: 687FST3126M Datasheet

Current PartRFQ

FST3126DR2G

onsemiIn Stock: 2246FST3126DR2G Datasheet

UpgradeRFQ

SN74CBT3126D

Texas InstrumentsIn Stock: 3671SN74CBT3126D Datasheet

DirectRFQ

SN74CBT3126DR

Texas InstrumentsIn Stock: 3573SN74CBT3126DR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the FST3126M is determined by the following critical parameters:

• Circuit Configuration: Must be 1 x 1:1 with 4 independent circuits
• Package Type: Must be 14-SOIC surface mount
• Voltage Supply: Must support single supply operation within compatible voltage ranges
• Mounting Compatibility: Surface mount only
• Moisture Sensitivity: MSL 1 (Unlimited) preferred for handling flexibility

Substitute parts are grouped into two categories based on manufacturer and product status:

Upgrade Path (onsemi): FST3126DR2G provides extended operating temperature range (-55°C ~ 125°C) with identical circuit configuration and packaging.

Direct Equivalents (Texas Instruments): SN74CBT3126D and SN74CBT3126DR offer identical circuit topology and packaging with Last Time Buy status, representing active alternatives from a different manufacturer.

Parameter Comparison

Engineering Selection Recommendations

For Extended Temperature Range Applications: FST3126DR2G is the appropriate upgrade path, offering -55°C ~ 125°C operating range compared to the original -40°C ~ 85°C specification. Both parts are onsemi products with identical circuit topology and 14-SOIC packaging.

For Standard Temperature Range with Active Product Status: SN74CBT3126D (Tube packaging) or SN74CBT3126DR (Tape & Reel packaging) from Texas Instruments provide Last Time Buy status, indicating longer availability windows than Obsolete parts. These devices maintain identical 1 x 1:1 circuit configuration and 14-SOIC packaging. Note the voltage supply range is 4.5V ~ 5.5V versus the original 4V ~ 5.5V.

For Procurement Continuity: Texas Instruments parts offer superior product lifecycle status (Last Time Buy versus Obsolete), supporting extended design support periods and procurement planning.

For Compliance Requirements: All substitute parts carry ROHS3 compliance certification and REACH Unaffected status, meeting modern environmental and regulatory standards.

Frequently Asked Questions (FAQ)

Q: Can FST3126DR2G be used as a direct replacement for FST3126M?

A: Yes. Both parts share identical circuit configuration (1 x 1:1), independent circuit count (4), package type (14-SOIC), and mounting method (surface mount). FST3126DR2G extends the operating temperature range to -55°C ~ 125°C. The voltage supply range remains 4V ~ 5.5V for both parts.

Q: What is the difference between SN74CBT3126D and SN74CBT3126DR?

A: Both parts are functionally identical with 1 x 1:1 circuit configuration and 14-SOIC packaging. The primary difference is packaging format: SN74CBT3126D is supplied in Tube format, while SN74CBT3126DR is supplied in Tape & Reel (TR) format. Selection depends on procurement and assembly requirements.

Q: Are there voltage supply compatibility concerns when substituting with Texas Instruments parts?

A: Texas Instruments SN74CBT3126D and SN74CBT3126DR specify a voltage supply range of 4.5V ~ 5.5V, compared to the FST3126M range of 4V ~ 5.5V. Applications requiring operation below 4.5V must use onsemi parts (FST3126M or FST3126DR2G).

Q: Why is product status important for this substitution?

A: FST3126M and FST3126DR2G carry Obsolete status, indicating limited future availability and support. SN74CBT3126D and SN74CBT3126DR carry Last Time Buy status, providing extended procurement windows and design support periods. For new designs or long-term production, Texas Instruments alternatives are preferred.

Q: Are all substitute parts RoHS compliant?

A: FST3126DR2G, SN74CBT3126D, and SN74CBT3126DR are all ROHS3 Compliant. The original FST3126M does not specify RoHS status in available documentation.

Q: Can these parts be used interchangeably in existing PCB designs?

A: Yes, all substitute parts use identical 14-SOIC surface mount packaging with matching pinout and footprint. PCB layout and assembly processes require no modification for substitution.