2N3904_J18Z Equivalent & Substitute Parts

Part Overview

The 2N3904_J18Z is a through-hole NPN bipolar junction transistor manufactured by onsemi, rated for 40 V collector-emitter breakdown voltage and 200 mA maximum collector current. This device is classified as obsolete, which necessitates identification of active equivalent parts for ongoing design support and procurement. The 2N3904_J18Z operates across a temperature range of -55°C to 150°C and is suitable for general-purpose switching and amplification applications in through-hole circuit designs.

Substiute Parts

2N3904_J18Z

onsemiIn Stock: 8402N3904_J18Z Datasheet

Current PartRFQ

2N3904BU

onsemiIn Stock: 221042N3904BU Datasheet

DirectRFQ

500-00001

Parallax Inc.In Stock: 880500-00001 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2N3904_J18Z is determined by strict equivalence across the following electrical and mechanical parameters:

• Transistor Type: NPN configuration
• Current Rating: 200 mA maximum collector current
• Voltage Rating: 40 V collector-emitter breakdown voltage
• Saturation Characteristics: 300 mV Vce saturation at specified base and collector currents
• Current Gain: Minimum 100 hFE at 10 mA collector current and 1 V Vce
• Frequency Response: 300 MHz transition frequency
• Temperature Range: -55°C to 150°C operating junction temperature
• Package: TO-92-3 through-hole configuration

Substitute parts must maintain all electrical specifications within the stated tolerances and operate within the defined temperature range. Package compatibility requires identical or functionally equivalent through-hole lead configurations.

Parameter Comparison

Engineering Selection Recommendations

2N3904BU (Direct Substitute)

The 2N3904BU is the primary equivalent for the obsolete 2N3904_J18Z. Both parts are manufactured by onsemi and share identical electrical specifications across all critical parameters: collector current, breakdown voltage, saturation characteristics, current gain, and frequency response. The 2N3904BU maintains active product status, ensuring long-term availability and supply chain continuity. This part is ROHS3 compliant and carries REACH Unaffected status, meeting modern regulatory requirements. The 2N3904BU is packaged in bulk format and is suitable for direct replacement in existing circuit designs without modification.

500-00001 (Similar Substitute)

The 500-00001 manufactured by Parallax Inc. provides functional equivalence with all core electrical parameters matching the 2N3904_J18Z specification. This part maintains the same collector current, breakdown voltage, saturation characteristics, current gain, and frequency response. The 500-00001 offers enhanced power dissipation capability at 1.5 W compared to the 625 mW rating of the main part, providing additional thermal margin in power-limited applications. The part is active and available. The 500-00001 is supplied in TO-92 package configuration with formed leads, which is mechanically compatible with TO-92-3 through-hole applications. The 500-00001 specifies a maximum collector cutoff current of 50 nA, providing additional leakage current specification not documented for the main part.

Frequently Asked Questions (FAQ)

Q: Can the 2N3904BU be used as a direct replacement for the 2N3904_J18Z?

A: Yes. The 2N3904BU is electrically and mechanically equivalent to the 2N3904_J18Z. Both parts share identical specifications for collector current, breakdown voltage, saturation voltage, current gain, and frequency response. The 2N3904BU is manufactured by the same supplier (onsemi) and uses the same TO-92-3 package configuration. The primary difference is product status: the 2N3904_J18Z is obsolete while the 2N3904BU is active.

Q: What is the difference between the 2N3904BU and the 500-00001?

A: Both parts meet the electrical requirements of the 2N3904_J18Z across all specified parameters. The 500-00001 is manufactured by Parallax Inc. rather than onsemi. The 500-00001 provides higher maximum power dissipation (1.5 W versus 625 mW) and specifies a maximum collector cutoff current of 50 nA. The 500-00001 is supplied with formed leads in TO-92 package configuration, which is mechanically compatible with TO-92-3 applications.

Q: Are there package compatibility concerns when substituting these parts?

A: The 2N3904BU uses the identical TO-92-3 package as the 2N3904_J18Z and requires no circuit board modifications. The 500-00001 is supplied in TO-92 package with formed leads, which is mechanically compatible with TO-92-3 through-hole footprints and does not require design changes.

Q: Which substitute part should be selected for new designs?

A: The 2N3904BU is the recommended selection for new designs. It is manufactured by onsemi (the original manufacturer of the 2N3904_J18Z), maintains active product status, and carries ROHS3 compliance certification. The 2N3904BU provides identical electrical performance and mechanical compatibility without requiring any circuit modifications.

Q: Can the 500-00001 be used in applications where thermal performance is critical?

A: The 500-00001 provides 1.5 W maximum power dissipation compared to the 625 mW rating of the 2N3904_J18Z. In applications where the transistor operates near its power limit, the 500-00001 offers additional thermal margin due to its higher power rating. However, all three parts operate within the same temperature range (-55°C to 150°C) and share identical electrical characteristics at rated conditions.

Q: What compliance certifications apply to these substitute parts?

A: The 2N3904BU carries ROHS3 compliance and REACH Unaffected status. The 500-00001 does not specify RoHS or REACH status in the provided documentation. Both parts are classified under ECCN EAR99 for export control purposes.