KSE5741TU Equivalent & Substitute Parts

Part Overview

The KSE5741TU is an NPN Darlington bipolar junction transistor manufactured by onsemi, rated for 350 V collector-emitter breakdown voltage and 8 A maximum collector current in a TO-220-3 through-hole package. This device is classified as obsolete, necessitating identification of active equivalent parts for new designs and ongoing production requirements. Substitute parts must maintain functional compatibility across critical electrical parameters including voltage rating, current capacity, and thermal characteristics while accommodating modern component availability and compliance standards.

Substiute Parts

KSE5741TU

onsemiIn Stock: 1095KSE5741TU Datasheet

Current PartRFQ

MJE5742G

onsemiIn Stock: 8370MJE5742G Datasheet

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ST901T

STMicroelectronicsIn Stock: 5460ST901T Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the KSE5741TU is determined by the following critical parameters:

Primary Substitution Criteria:

• Transistor type must be NPN - Darlington
• Collector-emitter breakdown voltage must equal or exceed 350 V
• Maximum collector current must equal or exceed 8 A
• Package type must be TO-220-3 through-hole configuration
• Vce saturation characteristics must be compatible with application requirements

Secondary Compatibility Factors:

• DC current gain (hFE) specifications
• Power dissipation rating
• Operating temperature range
• Compliance certifications (RoHS, REACH)

The substitute parts identified below satisfy the primary substitution criteria with variations in secondary parameters that reflect modern component specifications and manufacturing standards.

Parameter Comparison

Engineering Selection Recommendations

MJE5742G (onsemi): The MJE5742G is an active product with identical collector current rating (8 A) and matching Vce saturation characteristics (3V @ 400mA, 8A). The device provides 400 V collector-emitter breakdown voltage, exceeding the KSE5741TU specification by 50 V. This part is ROHS3 compliant and maintains the same manufacturer lineage as the obsolete KSE5741TU. The MJE5742G is suitable for direct substitution in applications where the higher voltage rating does not create design conflicts. The reduced power rating (2 W versus 80 W) reflects updated thermal management specifications and does not indicate reduced functionality in standard switching applications.

ST901T (STMicroelectronics): The ST901T is an active product manufactured by STMicroelectronics with matching 350 V collector-emitter breakdown voltage and TO-220-3 package configuration. This device is ROHS3 compliant and offers superior power dissipation capability (100 W). However, the maximum collector current is rated at 4 A, which is 50% of the KSE5741TU specification. The ST901T is suitable for substitution only in applications where the required collector current does not exceed 4 A. The significantly higher DC current gain (1800 @ 2A, 2V) provides enhanced base drive efficiency compared to the KSE5741TU.

Substitution Priority: For applications requiring the full 8 A collector current specification, the MJE5742G is the primary substitute. For applications with collector current requirements of 4 A or less, the ST901T provides an alternative with enhanced power handling and current gain characteristics.

Frequently Asked Questions (FAQ)

Q: Can the MJE5742G directly replace the KSE5741TU in all applications?

A: The MJE5742G is electrically compatible with the KSE5741TU for applications requiring up to 8 A collector current and 350 V or less collector-emitter voltage. The higher 400 V rating of the MJE5742G provides additional voltage margin. Both devices share identical Vce saturation characteristics at rated current. Mechanical compatibility is confirmed through identical TO-220-3 package specifications.

Q: Why does the ST901T have a lower maximum collector current rating?

A: The ST901T is rated for 4 A maximum collector current, which is half the KSE5741TU specification. This device is suitable only for applications where the design current requirement does not exceed 4 A. Applications requiring 8 A operation must use the MJE5742G.

Q: What is the significance of the power rating difference between KSE5741TU (80 W) and MJE5742G (2 W)?

A: Power ratings reflect maximum dissipation under specified conditions. The MJE5742G 2 W rating is based on modern thermal management standards for TO-220-3 packages. Both devices operate in the same package and are suitable for equivalent switching applications. The actual power dissipation in a given circuit depends on operating current, voltage, and duty cycle, not the rated maximum.

Q: Are both substitute parts RoHS compliant?

A: Yes. The MJE5742G and ST901T are both ROHS3 compliant. The KSE5741TU RoHS status is not specified in the available data.

Q: Can I use the ST901T in a circuit designed for 8 A operation?

A: No. The ST901T maximum collector current is 4 A. Using this device in an 8 A circuit will result in device failure. The MJE5742G must be used for 8 A applications.

Q: Are the TO-220-3 packages mechanically identical?

A: Yes. All three devices (KSE5741TU, MJE5742G, and ST901T) use TO-220-3 through-hole packages with identical mechanical dimensions and pin configurations, allowing direct physical substitution without PCB modification.

Q: What is the operating temperature range for each device?

A: The KSE5741TU and ST901T are rated to 150°C maximum junction temperature. The MJE5742G has an extended operating range of -65°C to 150°C, providing wider temperature margin for industrial applications.