KSC2258STU Equivalent & Substitute Parts

Part Overview

The KSC2258STU is an NPN bipolar junction transistor manufactured by onsemi, rated for 250 V collector-emitter breakdown voltage and 100 mA maximum collector current. This component is packaged in a TO-126-3 through-hole configuration and is designed for general-purpose switching and amplification applications requiring moderate voltage and current ratings.

The KSC2258STU is classified as obsolete. Locating equivalent or substitute components is necessary to support ongoing maintenance, repair, and new design requirements where this transistor is specified or where inventory depletion necessitates alternative sourcing.

Substiute Parts

KSC2258STU

onsemiIn Stock: 1209KSC2258STU Datasheet

Current PartRFQ

MJE340

NTE Electronics, IncIn Stock: 2035MJE340 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the KSC2258STU is determined by compatibility across the following critical electrical and mechanical parameters:

Transistor Type: Both the main part and substitute must be NPN configuration to maintain circuit polarity and biasing requirements.

Voltage Rating: The substitute must meet or exceed the 250 V collector-emitter breakdown voltage specification to ensure safe operation under maximum voltage stress conditions.

Current Rating: The substitute must support the required collector current. The KSC2258STU is rated for 100 mA maximum; substitutes with equal or higher current ratings are acceptable.

Power Dissipation: The substitute must have power handling capability equal to or greater than 4 W to accommodate thermal requirements.

DC Current Gain (hFE): The substitute must provide sufficient current gain to ensure proper biasing and switching performance in the intended application.

Package / Case: The substitute must be compatible with the TO-126-3 through-hole footprint to ensure mechanical fit and thermal management characteristics.

Mounting Type: Through-hole mounting compatibility is required for direct board-level substitution.

Parameter Comparison

Engineering Selection Recommendations

The MJE340 is a suitable substitute for the KSC2258STU based on the following engineering criteria:

Electrical Compatibility: The MJE340 exceeds the electrical specifications of the KSC2258STU across all rated parameters. The 300 V breakdown voltage rating exceeds the 250 V requirement. The 500 mA collector current rating exceeds the 100 mA requirement. The 20 W power rating exceeds the 4 W requirement. These higher ratings ensure the substitute can operate safely within the design envelope of the original component.

Transistor Configuration: Both components are NPN transistors, ensuring identical polarity and biasing characteristics for direct circuit substitution.

Package Compatibility: Both components use TO-126 through-hole packaging, providing mechanical and thermal compatibility with existing PCB layouts and mounting hardware.

Product Status: The KSC2258STU is obsolete, while the MJE340 is active and currently in production. This status difference ensures long-term availability and supply chain continuity for the substitute part.

Compliance: The MJE340 carries an ECCN classification of EAR99, consistent with the original part. RoHS compliance status differs between the two components; the MJE340 is RoHS non-compliant, which may be a consideration for applications subject to RoHS requirements.

Frequently Asked Questions (FAQ)

Q: Can the MJE340 be used as a direct replacement for the KSC2258STU in all applications?

A: The MJE340 meets or exceeds all critical electrical parameters of the KSC2258STU and shares compatible through-hole packaging. However, applications with specific RoHS compliance requirements should note that the MJE340 is RoHS non-compliant, whereas the KSC2258STU status is unaffected by REACH regulations. Circuit designers should verify that the higher power rating and current capability of the MJE340 do not introduce unintended behavior in current-limiting or thermal-sensitive applications.

Q: Are there any package differences between the KSC2258STU and MJE340?

A: Both components use TO-126 through-hole packaging. The KSC2258STU is specified as TO-126-3, while the MJE340 is specified as TO-126. These designations refer to the same physical package family and are mechanically compatible for PCB mounting and thermal management purposes.

Q: What is the significance of the higher current and power ratings on the MJE340?

A: The MJE340 is rated for 500 mA collector current and 20 W power dissipation, compared to the KSC2258STU ratings of 100 mA and 4 W. These higher ratings indicate the MJE340 can handle greater electrical stress without degradation. In applications where the KSC2258STU operates below its maximum ratings, the MJE340 provides additional design margin and reliability headroom.

Q: How do the DC current gain specifications compare?

A: The KSC2258STU specifies a minimum hFE of 40 at 40 mA collector current and 20 V collector-emitter voltage. The MJE340 specifies a minimum hFE of 30 at 50 mA and 10 V. These measurements are taken at different operating points, making direct numerical comparison imprecise. Both transistors provide sufficient current gain for typical switching and amplification circuits.

Q: Is the MJE340 suitable for high-frequency applications?

A: The KSC2258STU specifies a transition frequency of 100 MHz. The MJE340 transition frequency is not provided in the available data. Applications requiring operation at or near 100 MHz should evaluate the frequency response characteristics of the MJE340 independently before substitution.

Q: What should be considered regarding the RoHS compliance difference?

A: The KSC2258STU is REACH unaffected, while the MJE340 is RoHS non-compliant. Applications subject to RoHS directives or customer specifications requiring RoHS-compliant components should address this compliance difference during design review and procurement planning.