BFT93W,115 Equivalent & Substitute Parts

Part Overview

The BFT93W,115 is an RF transistor PNP type manufactured by NXP USA Inc., designed for high-frequency applications up to 4GHz. This component operates at 12V collector-emitter breakdown voltage with a maximum power dissipation of 300mW and collector current of 50mA in a surface mount SC-70 package. The part is classified as obsolete, making identification of suitable substitute components necessary for ongoing design support and production continuity.

Substiute Parts

BFT93W,115

NXP USA Inc.In Stock: 1039BFT93W,115 Datasheet

Current PartRFQ

MMBTH81

onsemiIn Stock: 15492MMBTH81 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BFT93W,115 is determined by the following critical electrical and mechanical parameters:

Transistor Configuration: PNP type required for circuit polarity compatibility.

Voltage Rating: Collector-emitter breakdown voltage must equal or exceed 12V. The substitute MMBTH81 provides 20V, which is acceptable for applications designed for 12V operation.

Frequency Performance: Transition frequency must support the intended RF application bandwidth. The BFT93W,115 operates at 4GHz; the MMBTH81 operates at 600MHz, limiting its use to lower-frequency applications within the original design envelope.

Current Capability: Maximum collector current of 50mA is maintained in the substitute part.

Power Dissipation: The BFT93W,115 dissipates 300mW maximum; the MMBTH81 dissipates 225mW. Applications requiring the full 300mW capability cannot use this substitute.

Package Compatibility: Both parts use surface mount technology. The BFT93W,115 uses SC-70 (SOT-323); the MMBTH81 uses SOT-23-3. PCB layout modifications are required.

Compliance: Both parts are ROHS3 compliant, REACH unaffected, and carry MSL 1 rating.

Parameter Comparison

Engineering Selection Recommendations

The MMBTH81 is the manufacturer-recommended substitute for the obsolete BFT93W,115. Selection of this substitute is based on the following factors:

Product Status: The BFT93W,115 is obsolete. The MMBTH81 is in active production, ensuring long-term availability and supply chain continuity.

Compliance Alignment: Both parts maintain ROHS3 compliance and REACH unaffected status, meeting current regulatory requirements.

Electrical Compatibility: Both transistors are PNP type with 50mA maximum collector current and MSL 1 moisture sensitivity rating, supporting equivalent handling and storage protocols.

Application Scope Limitations: The MMBTH81 operates at 600MHz transition frequency, compared to the BFT93W,115 at 4GHz. Substitution is limited to applications operating below 600MHz. Applications requiring 4GHz performance cannot use this substitute.

Power Dissipation Constraint: The MMBTH81 maximum power dissipation is 225mW versus 300mW for the BFT93W,115. Designs requiring full 300mW dissipation capability must use alternative substitutes or the original part if available from inventory.

Package Redesign Requirement: PCB layout modification is necessary due to package change from SC-70 to SOT-23-3.

Frequently Asked Questions (FAQ)

Q: Can the MMBTH81 directly replace the BFT93W,115 without circuit modifications?

A: No. While both are PNP transistors with compatible current ratings, the MMBTH81 operates at 600MHz transition frequency compared to 4GHz for the BFT93W,115. Applications designed for 4GHz operation cannot use the MMBTH81. Additionally, the package change from SC-70 to SOT-23-3 requires PCB layout redesign.

Q: What is the primary limitation of using MMBTH81 as a substitute?

A: Frequency performance is the primary limitation. The MMBTH81 transition frequency of 600MHz restricts its use to lower-frequency RF applications. The BFT93W,115 is designed for applications up to 4GHz.

Q: Are there compliance or handling differences between these parts?

A: No. Both parts are ROHS3 compliant, REACH unaffected, and carry MSL 1 (unlimited) moisture sensitivity rating. Handling, storage, and compliance protocols are equivalent.

Q: Does the higher voltage rating of MMBTH81 (20V vs 12V) create compatibility issues?

A: No. The higher voltage rating of the MMBTH81 is acceptable for circuits designed for 12V operation. The substitute can withstand higher voltage stress without degradation.

Q: What package considerations apply to this substitution?

A: The BFT93W,115 uses SC-70 (SOT-323) package; the MMBTH81 uses SOT-23-3 package. These packages have different pin spacing and footprints. PCB layout modification is required, including new land pattern design and trace routing.

Q: Is the MMBTH81 suitable for all applications using the BFT93W,115?

A: No. Substitution is limited to applications operating at or below 600MHz and requiring maximum power dissipation of 225mW or less. High-frequency applications above 600MHz or high-power applications exceeding 225mW require alternative solutions.