2SC4081RT1 Equivalent & Substitute Parts

Part Overview

The 2SC4081RT1 is an NPN bipolar junction transistor manufactured by onsemi, rated for 50 V collector-emitter breakdown voltage and 100 mA maximum collector current in a surface mount SC-70 (SOT-323) package. This part is classified as obsolete, which necessitates identification of equivalent and substitute components for ongoing design support and production continuity. The 200 mW power dissipation rating and general-purpose switching characteristics make this transistor suitable for low-power signal amplification and switching applications.

Substiute Parts

2SC4081RT1

onsemiIn Stock: 9772SC4081RT1 Datasheet

Current PartRFQ

MSC2712GT1G

onsemiIn Stock: 65185MSC2712GT1G Datasheet

DirectRFQ

BC847AW RFG

Taiwan Semiconductor CorporationIn Stock: 18956BC847AW RFG Datasheet

DirectRFQ

BC847BW-TP

Micro Commercial CoIn Stock: 4143BC847BW-TP Datasheet

DirectRFQ

BC850AW RFG

Taiwan Semiconductor CorporationIn Stock: 19004BC850AW RFG Datasheet

DirectRFQ

2PD601ARW,115

Nexperia USA Inc.In Stock: 9162PD601ARW,115 Datasheet

UpgradeRFQ

2PD601ASW,115

NXP USA Inc.In Stock: 7052072PD601ASW,115 Datasheet

UpgradeRFQ

2SC4081T106R

Rohm SemiconductorIn Stock: 1204642SC4081T106R Datasheet

SimilarRFQ

BC847AW-7-F

Diodes IncorporatedIn Stock: 47345BC847AW-7-F Datasheet

SimilarRFQ

BC847CW,135

Nexperia USA Inc.In Stock: 15815BC847CW,135 Datasheet

SimilarRFQ

BC850CW,135

Nexperia USA Inc.In Stock: 10466BC850CW,135 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2SC4081RT1 is determined by strict alignment of electrical and mechanical parameters. The critical substitution criteria are:

Mandatory Matching Parameters:

• Transistor Type: NPN
• Voltage - Collector Emitter Breakdown (Max): 50 V or higher
• Current - Collector (Ic) (Max): 100 mA or higher
• Power - Max: 200 mW or higher
• Package / Case: SC-70 or SOT-323 (surface mount)
• Mounting Type: Surface Mount

Acceptable Variation Parameters:

• DC Current Gain (hFE): May vary within device specifications
• Vce Saturation: May vary within device specifications
• Frequency - Transition: May exceed original specification
• Operating Temperature Range: May exceed original specification
• RoHS Compliance: May differ from original (RoHS3 compliant alternatives are preferred for new designs)

Substitute parts are categorized as Direct, Upgrade, or Similar based on how closely they match the original 2SC4081RT1 electrical and mechanical specifications.

Parameter Comparison

Engineering Selection Recommendations

Direct Substitutes (Highest Compatibility):

The MSC2712GT1G (onsemi) provides direct electrical equivalence with 50 V breakdown voltage and 100 mA collector current rating. However, the package differs (SC-59 vs. SC-70), requiring PCB layout modification. This part is active and RoHS3 compliant.

The 2PD601ARW,115 and 2PD601ASW,115 (Nexperia/NXP) maintain the 50 V breakdown voltage specification and SC-70 package compatibility. Both are active products with RoHS3 compliance and AEC-Q101 automotive qualification. The 2PD601ASW,115 offers higher DC current gain (290 vs. 210) and greater inventory availability.

Upgrade Substitutes (Enhanced Performance):

The 2PD601ARW,115 and 2PD601ASW,115 provide improved leakage current performance (10 nA vs. 100 nA) and higher transition frequency (100 MHz), while maintaining the original 50 V rating and SC-70 package. These parts are suitable for applications requiring enhanced reliability and automotive-grade qualification.

Compatible Alternatives (Reduced Voltage Rating):

The BC847AW RFG, BC847BW-TP, BC850AW RFG, BC847AW-7-F, BC847CW,135, and BC850CW,135 all feature 45 V breakdown voltage (5 V lower than the original), 100 mA collector current, and SC-70 package compatibility. These parts are active and RoHS3 compliant. Selection among these alternatives depends on DC current gain requirements and manufacturer availability.

Similar Specification (Higher Current Rating):

The 2SC4081T106R (Rohm Semiconductor) maintains the 50 V breakdown voltage and SC-70 package but offers 150 mA maximum collector current. This part is classified as "Not For New Designs" and should be used only for legacy system support.

Product Status Consideration:

All recommended substitutes are active products except 2SC4081T106R (Not For New Designs). For new designs, prioritize active status parts with RoHS3 compliance. The 2PD601ASW,115 offers the highest inventory availability (705,135 pcs) and automotive qualification.

Frequently Asked Questions (FAQ)

Q: Can I use BC847AW RFG as a direct replacement for 2SC4081RT1?

A: BC847AW RFG is electrically compatible for most applications. It maintains the 100 mA collector current and 200 mW power rating in the same SC-70 package. However, the breakdown voltage is 45 V versus the original 50 V. This 5 V reduction is acceptable for applications with design margins below 45 V. Verify your circuit's maximum collector-emitter voltage does not exceed 45 V.

Q: What is the difference between 2PD601ARW,115 and 2PD601ASW,115?

A: Both parts maintain 50 V breakdown voltage and SC-70 package compatibility. The primary differences are DC current gain (210 vs. 290 at 2 mA, 10V) and packaging format (Tape & Reel vs. Bulk). The 2PD601ASW,115 offers significantly higher inventory availability. Both are AEC-Q101 automotive qualified and RoHS3 compliant.

Q: Why does MSC2712GT1G use a different package (SC-59) than the original?

A: MSC2712GT1G is electrically equivalent but uses SC-59 (TO-236-3) instead of SC-70 (SOT-323). While both are surface mount packages with three leads, the physical dimensions and PCB footprints differ. PCB layout modification is required for this substitution.

Q: Is the 2SC4081T106R suitable for new designs?

A: No. The 2SC4081T106R is classified as "Not For New Designs" by Rohm Semiconductor. This designation indicates the manufacturer is discontinuing support. Use this part only for legacy system maintenance. For new designs, select from active status alternatives such as 2PD601ASW,115 or BC847BW-TP.

Q: What does RoHS3 compliance mean for my application?

A: RoHS3 compliance indicates the part meets Restriction of Hazardous Substances Directive requirements, restricting lead, cadmium, mercury, and other hazardous materials. The original 2SC4081RT1 is RoHS non-compliant. All recommended active substitutes are RoHS3 compliant, making them suitable for applications subject to environmental regulations.

Q: Can I use BC850CW,135 in place of 2SC4081RT1?

A: BC850CW,135 is compatible for most switching applications. It maintains 100 mA collector current, 200 mW power rating, and SC-70 package. The 45 V breakdown voltage is 5 V lower than the original. The significantly higher DC current gain (420 vs. 180) may affect circuit biasing; verify your design accommodates this difference.

Q: What is the significance of the transition frequency specification?

A: Transition frequency (fT) indicates the frequency at which current gain drops to unity. The original 2SC4081RT1 does not specify this parameter. Substitute parts range from 50 MHz (MSC2712GT1G) to 300 MHz (BC847AW-7-F). Higher transition frequency provides better high-frequency performance but is not required for low-frequency switching applications.

Q: Are all substitute parts available in the same tape and reel packaging?

A: Most substitutes are available in Tape & Reel (TR) format suitable for automated assembly. The 2PD601ASW,115 is supplied in Bulk format. Verify packaging format compatibility with your procurement and assembly processes before selection.