2STW100 Equivalent & Substitute Parts

Part Overview

The 2STW100 is an NPN Darlington bipolar junction transistor manufactured by STMicroelectronics, designed for high-current switching applications. This component features a maximum collector current of 25 A, collector-emitter breakdown voltage of 80 V, and maximum power dissipation of 130 W in a Through Hole TO-247-3 package. The 2STW100 is classified as obsolete, necessitating identification of functionally equivalent active alternatives for new designs and ongoing production requirements. Substitute parts must maintain electrical performance within specified operating parameters while offering current market availability.

Substiute Parts

2STW100

STMicroelectronicsIn Stock: 12502STW100 Datasheet

Current PartRFQ

TIP35C

NTE Electronics, IncIn Stock: 35314TIP35C Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2STW100 is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Collector current rating must equal or exceed 25 A maximum
• Collector-emitter breakdown voltage must equal or exceed 80 V
• Maximum power dissipation must equal or exceed 130 W
• Transistor polarity must be NPN type
• DC current gain must support the intended switching application

Mechanical Compatibility Criteria:

• Through Hole mounting type required
• Package form factor must accommodate TO-247-3 or equivalent footprint dimensions
• Lead configuration must support existing PCB layouts

Compliance Requirements:

• RoHS3 compliance required
• ECCN classification EAR99 maintained

The TIP35C qualifies as a functional substitute based on meeting or exceeding all critical electrical parameters while maintaining Through Hole mounting and RoHS3 compliance. Package differences between TO-247-3 and TO-218-3 require mechanical verification for specific applications.

Parameter Comparison

Engineering Selection Recommendations

The TIP35C is an active substitute for the obsolete 2STW100. Selection of this alternative is based on the following engineering factors:

Product Status Alignment: The TIP35C maintains Active product status, ensuring long-term availability and supply chain continuity compared to the Obsolete 2STW100.

Electrical Parameter Sufficiency: The TIP35C meets or exceeds all critical electrical specifications. The collector current rating of 25 A matches the original part. The collector-emitter breakdown voltage of 100 V exceeds the 2STW100 specification of 80 V, providing additional voltage margin. Maximum power dissipation of 125 W is within 4% of the original 130 W specification and remains suitable for equivalent thermal management designs.

Compliance Maintenance: Both parts maintain ROHS3 compliance and EAR99 ECCN classification, ensuring regulatory continuity in applications subject to these requirements.

Package Consideration: The TIP35C uses TO-218-3 packaging versus the 2STW100 TO-247-3 package. Both are Through Hole packages with different mechanical footprints. PCB layout modification is required to accommodate the TO-218-3 lead configuration and mounting hole spacing.

Transistor Type Difference: The 2STW100 is specified as NPN - Darlington, while the TIP35C is specified as NPN. This difference reflects the internal circuit architecture. The TIP35C operates as a standard NPN transistor and is suitable for applications previously served by the Darlington configuration, provided circuit design accounts for differences in base-emitter voltage characteristics.

Frequently Asked Questions (FAQ)

Q: Can the TIP35C directly replace the 2STW100 without PCB modifications?

A: No. While electrical parameters are compatible, the package change from TO-247-3 to TO-218-3 requires PCB layout modification. The lead spacing, mounting hole positions, and mechanical envelope differ between these packages. Physical verification of the new footprint against existing PCB designs is necessary.

Q: What is the significance of the Darlington configuration in the 2STW100?

A: The Darlington configuration in the 2STW100 provides higher DC current gain (500 @ 10A, 3V) compared to standard NPN transistors. The TIP35C, as a standard NPN transistor, has lower current gain (10 @ 15A, 4V). Circuit designs relying on high current gain for base drive reduction must account for this difference in base current requirements.

Q: Are there voltage rating differences between these parts?

A: Yes. The TIP35C has a collector-emitter breakdown voltage of 100 V, compared to 80 V for the 2STW100. This 20 V increase provides additional voltage margin and does not restrict substitution in applications operating within the original 80 V specification.

Q: What is the impact of the power rating difference?

A: The TIP35C maximum power dissipation is 125 W versus 130 W for the 2STW100. This 5 W reduction (approximately 4%) is within typical thermal design margins for most applications. Thermal management designs based on the original 130 W specification remain valid for the TIP35C.

Q: Does the frequency specification difference affect substitution?

A: The TIP35C specifies a transition frequency of 3 MHz, while the 2STW100 does not provide this parameter. For DC switching applications, this difference is not relevant. For AC or high-frequency applications, the 3 MHz specification of the TIP35C establishes the upper frequency limit for reliable operation.

Q: Are there compliance or certification differences?

A: Both parts maintain ROHS3 compliance and EAR99 ECCN classification. The TIP35C REACH status is listed as Vendor Undefined, whereas the 2STW100 is REACH Unaffected. Applications subject to REACH compliance requirements should confirm the TIP35C status with the supplier.

Q: What inventory considerations apply to this substitution?

A: The 2STW100 has 1231 pieces in stock as an obsolete part with limited future availability. The TIP35C has 35300 pieces in stock as an active product, providing significantly greater supply security for ongoing production and future requirements.