Equivalent & Substitute Parts for 2N4918

Part Overview

The 2N4918 is a PNP bipolar junction transistor manufactured by onsemi, designed for general-purpose switching and amplification applications. The device is rated for 40 V collector-emitter breakdown voltage, 1 A maximum collector current, and 30 W power dissipation in a Through Hole TO-126 package. The 2N4918 is classified as obsolete, making identification of suitable substitute components necessary for ongoing design support and production continuity. The 2N4918G represents the direct equivalent with improved compliance status and availability under Last Time Buy conditions.

Substiute Parts

2N4918

onsemiIn Stock: 36902N4918 Datasheet

Current PartRFQ

2N4918G

onsemiIn Stock: 34822N4918G Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2N4918 is determined by electrical and mechanical parameter equivalence. The primary substitute, 2N4918G, maintains identical electrical specifications across all critical parameters: PNP transistor type, 1 A maximum collector current, 40 V breakdown voltage, 600 mV saturation voltage, 30 W power rating, 3 MHz transition frequency, and -65°C to 150°C operating temperature range. Both devices utilize the TO-126-3 package for Through Hole mounting, ensuring mechanical compatibility.

The substitution logic is based on the following key parameters:

• Transistor polarity and type (PNP)
• Maximum collector current rating (1 A)
• Collector-emitter breakdown voltage (40 V)
• Saturation voltage characteristics (600 mV @ specified conditions)
• Power dissipation capability (30 W)
• Transition frequency (3 MHz)
• Package form factor (TO-126-3 Through Hole)
• Operating temperature range (-65°C to 150°C)

Parameter Comparison

Engineering Selection Recommendations

The 2N4918G is the direct electrical and mechanical equivalent of the 2N4918, with identical performance specifications across all rated parameters. Selection between these parts is determined by product lifecycle and regulatory compliance requirements.

The 2N4918 is classified as obsolete, indicating end-of-life status and limited availability for new production. The 2N4918G, designated as Last Time Buy, provides extended availability while maintaining full electrical equivalence. The 2N4918G additionally achieves ROHS3 compliance, whereas the 2N4918 is RoHS non-compliant. Both devices maintain REACH Unaffected status.

For applications requiring regulatory compliance with modern environmental standards, the 2N4918G is the appropriate selection. For legacy system maintenance where RoHS compliance is not mandated, either part satisfies the electrical and mechanical requirements. The TO-126-3 package ensures direct mechanical interchangeability in existing PCB designs without layout modification.

Frequently Asked Questions (FAQ)

Q: Can the 2N4918G directly replace the 2N4918 in existing designs?

A: Yes. The 2N4918G is electrically and mechanically equivalent to the 2N4918. All electrical parameters, including collector current, breakdown voltage, saturation voltage, power rating, transition frequency, and operating temperature range, are identical. Both devices use the TO-126-3 Through Hole package, enabling direct substitution without PCB redesign.

Q: What is the difference between the 2N4918 and 2N4918G?

A: The primary differences are product lifecycle status and regulatory compliance. The 2N4918 is obsolete with RoHS non-compliant status. The 2N4918G is Last Time Buy with ROHS3 compliance. Electrical and mechanical specifications are identical.

Q: Why is the 2N4918 classified as obsolete?

A: Obsolete classification indicates the manufacturer has discontinued production and support for this part number. The 2N4918G represents the current equivalent offering with extended availability under Last Time Buy conditions.

Q: Are there any thermal or performance differences between these parts?

A: No. Both the 2N4918 and 2N4918G are rated for identical maximum power dissipation (30 W), operating temperature range (-65°C to 150°C), and thermal characteristics. Performance in switching and amplification applications is equivalent.

Q: What does Last Time Buy status mean for the 2N4918G?

A: Last Time Buy indicates the manufacturer will continue to produce the part for a limited period before discontinuation. Customers requiring this component should secure inventory during this window. The 2N4918G maintains full electrical and mechanical specifications throughout its Last Time Buy period.

Q: Is the TO-126-3 package the same as TO-126?

A: The TO-126-3 designation specifies the three-lead TO-126 package configuration used for both the 2N4918 and 2N4918G. This is the standard Through Hole package for these transistors and ensures mechanical compatibility in existing designs.

Q: What are the key electrical parameters that define substitution for this transistor?

A: Substitution is determined by matching: transistor type (PNP), maximum collector current (1 A), collector-emitter breakdown voltage (40 V), saturation voltage (600 mV @ specified conditions), power rating (30 W), transition frequency (3 MHz), and operating temperature range (-65°C to 150°C). The 2N4918G meets all these criteria.

Q: Can the 2N4918 be used in new product designs?

A: The 2N4918 is obsolete and not recommended for new designs. The 2N4918G should be specified for new products to ensure long-term availability and regulatory compliance. Both parts are electrically equivalent, making the transition straightforward.