BD535 NPN Bipolar Transistor Equivalent & Substitute Parts

Part Overview

The BD535 is an NPN bipolar junction transistor manufactured by STMicroelectronics, designed for general-purpose switching and amplification applications. The device is rated for 60 V collector-emitter breakdown voltage, 8 A maximum collector current, and 50 W power dissipation in a Through Hole TO-220-3 package. The BD535 is classified as obsolete, making identification of functionally equivalent substitute components necessary for ongoing design support, maintenance, and production continuity.

Substiute Parts

BD535

STMicroelectronicsIn Stock: 5331BD535 Datasheet

Current PartRFQ

2N6290 PBFREE

Central Semiconductor CorpIn Stock: 7442N6290 PBFREE Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BD535 is determined by electrical and mechanical compatibility within the following criteria:

Primary Substitution Parameters:

• Transistor polarity (NPN type required)
• Collector-emitter breakdown voltage rating (minimum 60 V for direct substitution)
• Maximum collector current rating (minimum 8 A for direct substitution)
• Maximum power dissipation (minimum 50 W for direct substitution)
• Package type (TO-220-3 Through Hole required for mechanical compatibility)
• DC current gain (hFE) characteristics suitable for the intended application

The 2N6290 PBFREE is identified as a substitute part. However, this device exhibits reduced electrical ratings compared to the BD535 across multiple parameters, including collector-emitter breakdown voltage (50 V versus 60 V), maximum collector current (7 A versus 8 A), and maximum power dissipation (40 W versus 50 W). The 2N6290 PBFREE maintains NPN polarity, TO-220-3 package compatibility, and Through Hole mounting type. Both devices are classified as obsolete and comply with ROHS3 and REACH standards.

Parameter Comparison

Engineering Selection Recommendations

Direct Substitution Considerations:

The 2N6290 PBFREE is mechanically compatible with the BD535 through identical TO-220-3 package and Through Hole mounting specifications. Both devices are classified as obsolete and maintain equivalent compliance certifications (ROHS3 Compliant, REACH Unaffected).

Electrical Derating:

The 2N6290 PBFREE operates at reduced electrical ratings. The collector-emitter breakdown voltage is 50 V compared to 60 V on the BD535, representing a 16.7% reduction in voltage headroom. Maximum collector current is 7 A versus 8 A (12.5% reduction), and maximum power dissipation is 40 W versus 50 W (20% reduction). Vce saturation characteristics differ significantly, with the 2N6290 PBFREE exhibiting 3.5 V saturation at 3 A and 7 A compared to 800 mV saturation at 600 mA and 6 A on the BD535.

Application Suitability:

Substitution of the BD535 with the 2N6290 PBFREE is suitable only for applications where the reduced electrical ratings do not exceed circuit requirements. Circuits designed for the full 60 V, 8 A, 50 W capability of the BD535 require evaluation to confirm operation within the 50 V, 7 A, 40 W envelope of the 2N6290 PBFREE. The significant difference in saturation voltage characteristics necessitates circuit analysis for switching applications.

Frequently Asked Questions (FAQ)

Q: Can the 2N6290 PBFREE directly replace the BD535 in all applications?

A: No. While both devices share NPN polarity and TO-220-3 package compatibility, the 2N6290 PBFREE has reduced electrical ratings across voltage, current, and power parameters. Direct substitution is limited to applications where circuit requirements do not exceed the 2N6290 PBFREE specifications.

Q: What is the primary difference in electrical performance between these devices?

A: The BD535 provides 60 V breakdown voltage, 8 A collector current, and 50 W power dissipation. The 2N6290 PBFREE is rated for 50 V, 7 A, and 40 W respectively. Additionally, saturation voltage characteristics differ substantially, affecting switching performance in saturation-mode applications.

Q: Are both devices suitable for new designs?

A: Both the BD535 and 2N6290 PBFREE are classified as obsolete. Neither device is recommended for new designs. Current-generation NPN transistors with equivalent or superior ratings should be evaluated for new applications.

Q: Do the devices have identical package dimensions?

A: Both devices use the TO-220-3 Through Hole package, providing mechanical compatibility for PCB mounting and thermal management via heatsink attachment. Package dimensions are equivalent.

Q: What compliance certifications apply to both devices?

A: Both the BD535 and 2N6290 PBFREE are ROHS3 Compliant and REACH Unaffected, meeting current environmental and hazardous substance regulations.

Q: How do the DC current gain characteristics compare?

A: The BD535 specifies minimum hFE of 25 at 2 A and 2 V. The 2N6290 PBFREE specifies minimum hFE of 30 at 2.5 A and 4 V. These measurements are taken at different operating points, making direct comparison dependent on specific circuit conditions.

Q: Is the 2N6290 PBFREE a full electrical equivalent?

A: No. The 2N6290 PBFREE is a partial substitute with reduced electrical ratings. It is suitable only for applications where the lower voltage, current, and power specifications are acceptable.