74FST3861DTR2 Equivalent & Substitute Parts

Part Overview

The 74FST3861DTR2 is a bus switch IC with 10 x 1:1 circuit configuration in a 24-TSSOP package, manufactured by onsemi. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The part operates across a 4V to 5.5V supply range with an operating temperature range of -40°C to 85°C, suitable for single-supply logic applications requiring bus switching functionality.

Substiute Parts

74FST3861DTR2

onsemiIn Stock: 102274FST3861DTR2 Datasheet

Current PartRFQ

SN74CBT3861PWR

Texas InstrumentsIn Stock: 5433SN74CBT3861PWR Datasheet

DirectRFQ

PI5C3861QE

Diodes IncorporatedIn Stock: 1804PI5C3861QE Datasheet

SimilarRFQ

PI5C3861QEX

Diodes IncorporatedIn Stock: 2192PI5C3861QEX Datasheet

SimilarRFQ

SN74CBT3861DBQR

Texas InstrumentsIn Stock: 4124SN74CBT3861DBQR Datasheet

SimilarRFQ

SN74CBT6800APWR

Texas InstrumentsIn Stock: 3150SN74CBT6800APWR Datasheet

Parametric EquivalentRFQ

SN74CBT6800CPWR

Texas InstrumentsIn Stock: 2186SN74CBT6800CPWR Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 74FST3861DTR2 is determined by the following critical parameters:

• Circuit configuration (10 x 1:1 bus switch topology)
• Package type and physical dimensions (24-TSSOP or compatible 24-pin packages)
• Voltage supply range compatibility (minimum 4V operation required)
• Operating temperature range (-40°C to 85°C)
• Single supply operation

Substitute parts are grouped into two categories:

Direct Substitutes maintain identical package and electrical specifications, enabling pin-for-pin replacement.

Similar Substitutes provide equivalent functionality with package variations (24-QSOP or 24-SSOP) that require PCB layout verification but maintain electrical compatibility within the specified voltage and temperature ranges.

Parametric Equivalents offer the same circuit function and package but use different base product numbers from the same manufacturer family, suitable when direct part availability is limited.

Parameter Comparison

Engineering Selection Recommendations

SN74CBT3861PWR (Texas Instruments) is the primary direct substitute. It maintains the 24-TSSOP package and identical circuit configuration with active product status and ROHS3 compliance. The voltage supply range narrows to 4.5V minimum, which is acceptable for standard 5V logic applications.

SN74CBT6800CPWR (Texas Instruments) provides an alternative with active product status and full voltage range compatibility (4V ~ 5.5V). This part maintains the 24-TSSOP package and is available in Tape & Reel packaging for production volumes.

SN74CBT6800APWR (Texas Instruments) offers the same electrical and package specifications as SN74CBT6800CPWR with Last Time Buy status, suitable for designs where supply continuity is not critical.

SN74CBT3861DBQR (Texas Instruments) provides a similar substitute with 24-SSOP package (0.154" width versus 0.173" for TSSOP). This requires PCB layout verification due to package width difference but maintains electrical compatibility and ROHS3 compliance.

PI5C3861QE and PI5C3861QEX (Diodes Incorporated) are similar substitutes with 24-QSOP packages. Both have narrower voltage supply ranges (4.75V ~ 5.25V) and Last Time Buy status. Package width is 0.154", requiring layout verification.

For new designs, SN74CBT3861PWR or SN74CBT6800CPWR are recommended due to active product status and full RoHS compliance. For existing designs with 24-TSSOP footprints, direct package compatibility is maintained.

Frequently Asked Questions (FAQ)

Q: Can SN74CBT3861PWR directly replace 74FST3861DTR2 without PCB modifications?

A: Yes. Both parts use the 24-TSSOP package with identical 0.173" width and pin configuration, enabling direct pin-for-pin replacement without PCB layout changes.

Q: What is the voltage supply difference between 74FST3861DTR2 and SN74CBT3861PWR?

A: The 74FST3861DTR2 operates from 4V to 5.5V, while SN74CBT3861PWR operates from 4.5V to 5.5V. For standard 5V logic systems, this difference is not significant. Applications requiring 4V operation must use SN74CBT6800APWR or SN74CBT6800CPWR.

Q: Why do PI5C3861QE and PI5C3861QEX have narrower voltage ranges?

A: These Diodes Incorporated parts specify 4.75V to 5.25V operation. This narrower range reflects the device characterization and does not indicate reduced functionality within standard 5V logic applications.

Q: Can I use SN74CBT3861DBQR as a substitute if my PCB has a 24-TSSOP footprint?

A: No. SN74CBT3861DBQR uses a 24-SSOP package with 0.154" width, while the original part uses 24-TSSOP with 0.173" width. The footprint difference requires PCB redesign.

Q: What is the difference between SN74CBT6800APWR and SN74CBT6800CPWR?

A: Both parts are electrically identical with the same 24-TSSOP package and voltage/temperature specifications. SN74CBT6800APWR is Last Time Buy status, while SN74CBT6800CPWR is Active. SN74CBT6800CPWR is preferred for new designs requiring long-term availability.

Q: Are all substitute parts RoHS compliant?

A: All substitute parts listed are ROHS3 compliant. The original 74FST3861DTR2 is RoHS non-compliant. If RoHS compliance is required, substitute parts must be selected from the compliant options.

Q: Which substitute has the best long-term availability?

A: SN74CBT3861PWR and SN74CBT6800CPWR both have Active product status, indicating ongoing manufacturing and availability. These are preferred for designs requiring extended component lifecycle support.