2N3391A Equivalent & Substitute Parts

Part Overview

The 2N3391A is an NPN bipolar junction transistor manufactured by onsemi, designed for general-purpose switching and amplification applications. This device features a maximum collector current of 500 mA, collector-emitter breakdown voltage of 25 V, and maximum power dissipation of 625 mW in a Through Hole TO-92-3 package. The 2N3391A is classified as obsolete, making identification of functionally equivalent substitute components necessary for ongoing design support and procurement continuity.

Substiute Parts

2N3391A

onsemiIn Stock: 188242N3391A Datasheet

Current PartRFQ

ZTX649

Diodes IncorporatedIn Stock: 8237ZTX649 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2N3391A is determined by the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Transistor polarity must be NPN
• Collector-emitter breakdown voltage must equal or exceed 25 V
• Maximum collector current must equal or exceed 500 mA
• Collector cutoff current must not exceed 100 nA
• Operating temperature range must encompass the application requirements

Mechanical Compatibility Criteria:

• Mounting type must be Through Hole
• Package must be physically compatible with TO-92-3 footprint or equivalent pin configuration

The ZTX649 from Diodes Incorporated satisfies all substitution criteria. This device exceeds the electrical specifications of the 2N3391A while maintaining Through Hole mounting compatibility with a TO-92 compatible E-Line package.

Parameter Comparison

Engineering Selection Recommendations

ZTX649 as Primary Substitute:

The ZTX649 is the appropriate substitute for the 2N3391A based on the following factors:

1. Product Status: The ZTX649 is classified as Active, ensuring ongoing availability and manufacturing support, whereas the 2N3391A is Obsolete.

2. Electrical Specifications: The ZTX649 meets or exceeds all critical electrical parameters of the 2N3391A. Maximum collector current is rated at 2 A (versus 500 mA), and maximum power dissipation is 1 W (versus 625 mW), providing design margin for existing applications.

3. Voltage Rating: Both devices share identical collector-emitter breakdown voltage of 25 V, ensuring direct voltage compatibility.

4. Mechanical Compatibility: The ZTX649 E-Line package is physically compatible with TO-92-3 footprints, supporting direct board-level substitution without layout modification.

5. Compliance: The ZTX649 carries RoHS3 compliance certification, meeting current regulatory requirements. Both devices are REACH Unaffected and classified under ECCN EAR99.

6. Temperature Range: The ZTX649 operating temperature range extends to 200°C, exceeding the 2N3391A specification of 150°C.

Frequently Asked Questions (FAQ)

Q: Can the ZTX649 be used as a direct replacement for the 2N3391A in existing designs?

A: Yes. The ZTX649 is electrically and mechanically compatible with the 2N3391A. The E-Line package is physically compatible with TO-92-3 footprints. The ZTX649 exceeds the electrical specifications of the 2N3391A, providing design margin without requiring circuit modification.

Q: What are the key differences between the 2N3391A and ZTX649?

A: The primary differences are: (1) Product Status—ZTX649 is Active while 2N3391A is Obsolete; (2) Maximum Collector Current—ZTX649 is rated at 2 A versus 500 mA; (3) Maximum Power Dissipation—ZTX649 is rated at 1 W versus 625 mW; (4) Operating Temperature Maximum—ZTX649 extends to 200°C versus 150°C; (5) Transition Frequency—ZTX649 is specified at 240 MHz; (6) Compliance—ZTX649 carries RoHS3 certification.

Q: Are there any package considerations when substituting the ZTX649 for the 2N3391A?

A: The ZTX649 uses an E-Line package that is TO-92 compatible. Both devices are Through Hole mounted with three-pin configurations. Physical footprint compatibility is maintained, allowing direct board-level substitution without PCB redesign.

Q: What is the DC current gain difference between these devices?

A: The 2N3391A specifies minimum DC current gain (hFE) of 250 at 2 mA and 4.5 V. The ZTX649 specifies minimum DC current gain of 100 at 1 A and 2 V. These measurements are taken at different operating points, reflecting the different current ratings of each device. The ZTX649 maintains adequate current gain for switching applications across its operating range.

Q: Is the ZTX649 suitable for high-temperature applications?

A: The ZTX649 is rated for operation up to 200°C junction temperature, compared to the 2N3391A maximum of 150°C. Applications requiring extended temperature operation benefit from the ZTX649's higher temperature rating.

Q: What compliance certifications apply to the ZTX649?

A: The ZTX649 is RoHS3 Compliant and REACH Unaffected. Both the 2N3391A and ZTX649 are classified under ECCN EAR99 for export control purposes.