ZTX457STZ Equivalent & Substitute Parts

Part Overview

The ZTX457STZ is an NPN bipolar junction transistor manufactured by Diodes Incorporated, designed for general-purpose switching and amplification applications. This through-hole component operates at 300 V collector-emitter breakdown voltage with a maximum collector current of 500 mA and 1 W power dissipation capability. The device is packaged in an E-Line (TO-92 compatible) configuration with formed leads suitable for through-hole mounting.

The ZTX457STZ maintains Active product status with full RoHS3 compliance and REACH unaffected classification. Equivalent and substitute parts are identified to support design flexibility, inventory management, and supply chain continuity for applications requiring NPN transistor functionality within specified electrical and mechanical parameters.

Substiute Parts

ZTX457STZ

Diodes IncorporatedIn Stock: 10121ZTX457STZ Datasheet

Current PartRFQ

2N6517TA

onsemiIn Stock: 82142N6517TA Datasheet

MFR RecommendedRFQ

KSP42TA

onsemiIn Stock: 55353KSP42TA Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the ZTX457STZ is determined by electrical and mechanical compatibility across the following critical parameters:

Electrical Compatibility Criteria:

• Transistor type must be NPN
• Collector-emitter breakdown voltage must equal or exceed 300 V
• Maximum collector current must equal or exceed 500 mA
• Power dissipation capability must support application requirements
• Transition frequency must be adequate for switching speed requirements

Mechanical Compatibility Criteria:

• Mounting type must be through-hole
• Package configuration must be physically compatible with E-Line (TO-92) footprint
• Formed leads must accommodate standard through-hole PCB hole spacing

Compliance Criteria:

• RoHS3 compliance required
• REACH unaffected status required
• Active product status preferred for long-term availability

The identified substitute parts (2N6517TA and KSP42TA) satisfy these criteria with electrical parameters that meet or exceed the ZTX457STZ specifications, ensuring functional equivalence within the defined application envelope.

Parameter Comparison

Engineering Selection Recommendations

ZTX457STZ (Primary Part): The ZTX457STZ is the specified component with Active product status, full RoHS3 compliance, and REACH unaffected classification. This part provides 1 W power dissipation and 75 MHz transition frequency. Selection is appropriate for applications requiring the full power rating and moderate switching speeds within the 300 V operating envelope.

2N6517TA (Substitute - Higher Voltage Rating): The 2N6517TA is an Active product from onsemi with RoHS3 compliance and REACH unaffected status. This substitute provides 350 V collector-emitter breakdown voltage, exceeding the ZTX457STZ specification by 50 V. The 2N6517TA delivers 200 MHz transition frequency, suitable for higher-speed switching applications. Power dissipation is 625 mW, which is lower than the primary part. This substitute is appropriate for applications requiring enhanced voltage margin or higher switching frequencies within the 500 mA collector current envelope.

KSP42TA (Substitute - Matched Voltage Rating): The KSP42TA is an Active product from onsemi with RoHS3 compliance and REACH unaffected status. This substitute matches the 300 V collector-emitter breakdown voltage of the ZTX457STZ and maintains 500 mA maximum collector current. The KSP42TA provides 50 MHz transition frequency, suitable for lower-speed switching applications. Power dissipation is 625 mW. This substitute is appropriate for applications where voltage and current ratings are primary selection criteria and switching frequency requirements are moderate.

All three parts maintain through-hole mounting compatibility with E-Line/TO-92 footprints and satisfy compliance requirements for RoHS3 and REACH classifications.

Frequently Asked Questions (FAQ)

Q: Can the 2N6517TA replace the ZTX457STZ in all applications?

A: The 2N6517TA is electrically compatible for applications operating at or below 300 V collector-emitter voltage. The higher 350 V rating provides additional voltage margin. However, the 2N6517TA power dissipation is 625 mW compared to the ZTX457STZ 1 W rating. Applications requiring the full 1 W power dissipation must verify that the 2N6517TA power budget is adequate for the specific circuit design.

Q: What is the difference between the KSP42TA and 2N6517TA substitutes?

A: Both are onsemi NPN transistors with 500 mA maximum collector current and through-hole TO-92-3 packaging. The 2N6517TA provides 350 V breakdown voltage and 200 MHz transition frequency, while the KSP42TA provides 300 V breakdown voltage and 50 MHz transition frequency. The KSP42TA matches the ZTX457STZ voltage rating exactly. Selection between these substitutes depends on whether higher voltage margin or higher switching frequency is required for the application.

Q: Are the package dimensions identical between ZTX457STZ and the substitute parts?

A: The ZTX457STZ uses E-Line-3 packaging (TO-92 compatible), while both substitute parts use TO-226-3/TO-92-3 packaging. Both package types are physically compatible with standard through-hole E-Line/TO-92 PCB footprints and formed lead configurations. Pin spacing and hole diameter compatibility are maintained across all three parts.

Q: What compliance certifications apply to all three parts?

A: All three parts (ZTX457STZ, 2N6517TA, and KSP42TA) are RoHS3 compliant and REACH unaffected. All maintain Active product status, ensuring continued availability and support from their respective manufacturers.

Q: How do the DC current gain specifications compare?

A: The ZTX457STZ specifies minimum hFE of 50 at 50 mA collector current and 10 V Vce. The 2N6517TA specifies minimum hFE of 20 at the same conditions, while the KSP42TA specifies minimum hFE of 40 at 30 mA collector current and 10 V Vce. Applications with specific current gain requirements must verify that the selected substitute meets the circuit design specifications.

Q: Which substitute is best for high-frequency switching applications?

A: The 2N6517TA provides 200 MHz transition frequency, compared to 75 MHz for the ZTX457STZ and 50 MHz for the KSP42TA. The 2N6517TA is appropriate for applications requiring higher switching speeds. However, power dissipation at 625 mW must be verified against circuit requirements.

Q: Can these parts be used interchangeably on the same PCB?

A: Yes. All three parts use through-hole E-Line/TO-92 packaging with compatible formed leads and pin spacing. Direct substitution on existing PCBs is mechanically feasible. Electrical verification of circuit performance is required to confirm functional equivalence for the specific application.