MJF122 Equivalent & Substitute Parts

Part Overview

The MJF122 is a Bipolar (BJT) Transistor NPN - Darlington configuration rated for 100 V collector-emitter breakdown voltage and 5 A maximum collector current. This component is packaged in a Through Hole TO-220-3 Full Pack (TO-220FP) format with a maximum power dissipation of 2 W and operates across a temperature range of -65°C to 150°C.

The MJF122 carries an Obsolete product status. Locating equivalent substitute parts is necessary to maintain design continuity and ensure component availability for new production builds, repairs, and system upgrades where this transistor is specified.

Substiute Parts

MJF122

onsemiIn Stock: 2146MJF122 Datasheet

Current PartRFQ

MJF122G

onsemiIn Stock: 25127MJF122G Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MJF122 is determined by strict equivalence across the following electrical and mechanical parameters:

• Transistor Configuration: NPN - Darlington topology
• Maximum Collector Current: 5 A
• Maximum Collector-Emitter Breakdown Voltage: 100 V
• Saturation Voltage Characteristics: 3.5V @ 20mA, 5A
• Collector Cutoff Current: 10µA
• DC Current Gain (hFE): 2000 @ 3A, 3V minimum
• Power Dissipation: 2 W maximum
• Operating Temperature Range: -65°C to 150°C
• Physical Package: TO-220-3 Full Pack (TO-220FP) Through Hole

The MJF122G is identified as a direct substitute based on identical electrical specifications and mechanical compatibility across all parameters listed above.

Parameter Comparison

Engineering Selection Recommendations

The MJF122G is the direct equivalent substitute for the obsolete MJF122. Both components share identical electrical specifications and mechanical packaging, ensuring functional interchangeability in circuit applications.

The primary distinction between the two parts is product status and regulatory compliance. The MJF122 is classified as Obsolete with RoHS non-compliant status, while the MJF122G maintains Active product status and achieves ROHS3 compliance. For new designs and production builds subject to RoHS regulations, the MJF122G is the appropriate selection. For legacy system maintenance where RoHS compliance is not a requirement, either part satisfies the electrical and mechanical specifications.

Both components carry identical REACH Unaffected and EAR99 ECCN classifications, indicating equivalent regulatory treatment for export and supply chain purposes.

Frequently Asked Questions (FAQ)

Q: Can the MJF122G be used as a direct replacement for the MJF122 in existing circuit designs?

A: Yes. The MJF122G provides identical electrical performance across all specified parameters including collector current, breakdown voltage, saturation characteristics, current gain, and power dissipation. The TO-220FP package dimensions and pin configuration are identical, enabling direct PCB-level substitution without circuit modification.

Q: What is the primary reason to transition from MJF122 to MJF122G?

A: The MJF122 is classified as Obsolete, making long-term component availability uncertain. The MJF122G maintains Active product status with established supply channels. Additionally, the MJF122G achieves ROHS3 compliance, meeting regulatory requirements for products sold in markets with RoHS mandates.

Q: Are there packaging differences between MJF122 and MJF122G?

A: Both components use the TO-220-3 Full Pack (TO-220FP) Through Hole package. The MJF122G is supplied in Tube packaging format, while the MJF122 packaging format is not specified. This distinction affects handling and storage but does not impact electrical or mechanical compatibility.

Q: Do the MJF122 and MJF122G have identical thermal characteristics?

A: Both components operate across the same temperature range of -65°C to 150°C (junction temperature) and dissipate a maximum of 2 W. Thermal performance is determined by identical power ratings and operating specifications.

Q: Are there any compliance or certification differences that affect component selection?

A: The MJF122G is ROHS3 compliant, while the MJF122 is RoHS non-compliant. Both share identical REACH Unaffected and EAR99 ECCN classifications. Component selection should account for applicable regulatory requirements in the target market and application.