MJ802 Equivalent & Substitute Parts

Part Overview

The MJ802 is an NPN bipolar junction transistor manufactured by STMicroelectronics, rated for 90 V collector-emitter breakdown voltage and 30 A maximum collector current. The device is housed in a TO-3 chassis mount package and delivers 200 W maximum power dissipation with a 2 MHz transition frequency. The MJ802 is classified as obsolete, making identification of functionally equivalent active alternatives necessary for ongoing design support and procurement continuity.

Substiute Parts

MJ802

STMicroelectronicsIn Stock: 1231MJ802 Datasheet

Current PartRFQ

MJ802G

onsemiIn Stock: 33113MJ802G Datasheet

DirectRFQ

2N5671

Microchip TechnologyIn Stock: 11262N5671 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MJ802 is determined by matching the following critical electrical and mechanical parameters:

Electrical Criteria:

• Transistor type: NPN configuration
• Voltage rating: Collector-emitter breakdown voltage of 90 V or greater
• Current rating: Maximum collector current of 30 A or greater
• Power dissipation: Maximum power rating of 200 W or greater
• Frequency response: Transition frequency of 2 MHz or greater

Mechanical Criteria:

• Package type: TO-3 or TO-204AA (equivalent mechanical form factor)
• Mounting compatibility: Through-hole or chassis mount configuration

Two substitute parts meet these criteria with varying degrees of parameter alignment:

MJ802G (onsemi): Direct electrical and mechanical equivalent with identical ratings across all critical parameters. Active product status with ROHS3 compliance.

2N5671 (Microchip Technology): Electrical compatibility confirmed for voltage and current ratings. Deviations exist in power dissipation (6 W versus 200 W), saturation voltage characteristics, and cutoff current specifications. Active product status but RoHS non-compliant.

Parameter Comparison

Engineering Selection Recommendations

MJ802G (onsemi) is the primary substitute for the obsolete MJ802. This part maintains identical electrical specifications across all critical parameters: 90 V breakdown voltage, 30 A collector current, 200 W power dissipation, and 2 MHz transition frequency. The MJ802G carries active product status and holds ROHS3 compliance certification, supporting long-term design continuity and regulatory requirements. The through-hole mounting configuration is mechanically compatible with TO-3 package footprints. This part is recommended for direct replacement in applications requiring full parameter equivalence.

2N5671 (Microchip Technology) is an alternative substitute with confirmed voltage and current compatibility but significant deviations in power dissipation and saturation characteristics. The 2N5671 is rated for 6 W maximum power versus the 200 W specification of the MJ802, and exhibits higher saturation voltage (5 V at 30 A versus 800 mV at 7.5 A). The 2N5671 carries active product status but does not meet RoHS compliance requirements. This part is suitable only for applications where the reduced power rating and altered saturation behavior do not impact circuit performance. The higher cutoff current (10 mA versus 1 mA) may affect leakage-sensitive applications.

Frequently Asked Questions (FAQ)

Q: Can MJ802G be used as a direct replacement for MJ802 in all applications?

A: Yes. The MJ802G maintains identical electrical ratings for voltage, current, power dissipation, and frequency response. The through-hole mounting configuration is mechanically compatible with TO-3 package footprints. No circuit modifications are required.

Q: What are the key differences between MJ802 and 2N5671?

A: The 2N5671 differs in three critical areas: (1) Power dissipation is rated at 6 W versus 200 W, limiting use in high-power applications; (2) Saturation voltage is 5 V at 30 A versus 800 mV at 7.5 A, affecting switching efficiency; (3) Collector cutoff current is 10 mA versus 1 mA, increasing leakage current. These differences restrict 2N5671 use to low-power or non-critical applications.

Q: Why is the MJ802 classified as obsolete?

A: The MJ802 is no longer manufactured by STMicroelectronics. The MJ802G from onsemi provides an active, functionally equivalent alternative with identical specifications and improved long-term availability.

Q: Are there packaging differences between MJ802 and its substitutes?

A: The MJ802 is specified as chassis mount; MJ802G and 2N5671 are through-hole mounted. Both configurations use the TO-3 package form factor and are mechanically compatible with standard TO-3 footprints. Mounting method differences do not affect electrical performance.

Q: Does RoHS compliance matter for substitute selection?

A: RoHS compliance is a regulatory requirement in many markets. The MJ802G is ROHS3 compliant, supporting compliance-driven procurement. The 2N5671 is RoHS non-compliant and may not be acceptable in regulated applications or regions with RoHS mandates.

Q: What is the operating temperature range for each part?

A: The MJ802 specifies a maximum junction temperature of 200°C. The MJ802G operates from −65°C to 200°C. The 2N5671 operates from −65°C to 200°C. All three parts support the same maximum temperature rating.

Q: Can 2N5671 be used in high-power switching applications?

A: No. The 2N5671 is rated for 6 W maximum power dissipation, making it unsuitable for applications requiring 200 W power handling. Use of 2N5671 in high-power circuits will result in thermal failure.