2N4125BU Equivalent & Substitute Parts

Part Overview

The 2N4125BU is a PNP bipolar junction transistor manufactured by onsemi, rated for 30 V collector-emitter breakdown voltage and 200 mA maximum collector current in a Through Hole TO-92-3 package. This device is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The 2N4125BU serves general-purpose switching and amplification applications requiring PNP transistor functionality within the specified voltage and current ratings.

Substiute Parts

2N4125BU

onsemiIn Stock: 11672N4125BU Datasheet

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2N4058 PBFREE

Central Semiconductor CorpIn Stock: 9372N4058 PBFREE Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2N4125BU is determined by strict equivalence of the following electrical and mechanical parameters:

• Transistor Type: PNP configuration required
• Maximum Collector Current (Ic): 200 mA minimum rating
• Collector-Emitter Breakdown Voltage: 30 V minimum rating
• Maximum Power Dissipation: 625 mW minimum rating
• Mounting Type: Through Hole configuration
• Package: TO-92-3 compatible form factor

The 2N4058 PBFREE from Central Semiconductor Corp meets all substitution criteria. Both devices share identical maximum ratings for collector current, breakdown voltage, and power dissipation. Both are packaged in TO-92-3 Through Hole configuration, ensuring mechanical and electrical compatibility in existing circuit designs.

Parameter Comparison

Engineering Selection Recommendations

2N4058 PBFREE is the direct substitute for 2N4125BU applications. The 2N4058 PBFREE is classified as Active product status, ensuring continued availability and manufacturing support, whereas the 2N4125BU is obsolete. Both devices are REACH Unaffected and carry EAR99 ECCN classification.

The 2N4058 PBFREE provides ROHS3 compliance certification, meeting modern environmental and regulatory requirements. The substitute device operates across an extended lower temperature range (-65°C minimum versus -55°C), providing additional margin for low-temperature applications. Both devices share identical maximum electrical ratings and TO-92-3 Through Hole packaging, enabling direct circuit substitution without design modification.

The 2N4058 PBFREE demonstrates higher DC current gain (hFE minimum of 100 versus 50) and higher collector cutoff current (100 nA versus 50 nA), representing minor parametric differences that remain within typical circuit tolerance margins for general-purpose switching and amplification applications.

Frequently Asked Questions (FAQ)

Q: Can the 2N4058 PBFREE directly replace the 2N4125BU in existing designs?

A: Yes. Both devices share identical maximum ratings for collector current (200 mA), collector-emitter breakdown voltage (30 V), and power dissipation (625 mW). Both are packaged in TO-92-3 Through Hole configuration. Direct substitution is electrically and mechanically compatible.

Q: What is the primary reason for substituting the 2N4125BU?

A: The 2N4125BU is classified as obsolete. The 2N4058 PBFREE is an active product with ongoing manufacturing support and availability.

Q: Are there package compatibility concerns?

A: No. Both the 2N4125BU and 2N4058 PBFREE use the TO-92-3 (TO-226AA) Through Hole package. Pin configuration and mechanical form factor are identical.

Q: How do the DC current gain specifications differ?

A: The 2N4125BU specifies minimum hFE of 50 at 2 mA collector current and 1 V collector-emitter voltage. The 2N4058 PBFREE specifies minimum hFE of 100 at 100 µA collector current and 5 V collector-emitter voltage. The 2N4058 PBFREE exhibits higher current gain, which is beneficial for switching applications requiring lower base drive current.

Q: What compliance advantages does the 2N4058 PBFREE offer?

A: The 2N4058 PBFREE is ROHS3 compliant, meeting current environmental regulations. Both devices are REACH Unaffected and carry EAR99 ECCN classification.

Q: Does the extended temperature range of the 2N4058 PBFREE provide operational advantages?

A: The 2N4058 PBFREE operates from -65°C to 150°C, compared to the 2N4125BU range of -55°C to 150°C. The extended lower temperature limit provides additional margin for applications requiring operation at lower ambient temperatures.