STL128DNFP Equivalent & Substitute Parts

Part Overview

The STL128DNFP is a Bipolar (BJT) NPN transistor manufactured by STMicroelectronics, rated for 400 V collector-emitter breakdown voltage and 4 A maximum collector current in a Through Hole TO-220FP package. This component is designed for high-voltage switching and amplification applications requiring 28 W power dissipation capability.

The STL128DNFP is classified as obsolete. Locating equivalent substitute parts is necessary to support ongoing maintenance, repair, and production requirements for legacy systems and equipment utilizing this transistor.

Substiute Parts

STL128DNFP

STMicroelectronicsIn Stock: 3203STL128DNFP Datasheet

Current PartRFQ

FJPF3305H1TU

onsemiIn Stock: 1737FJPF3305H1TU Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the STL128DNFP are identified based on strict electrical and mechanical parameter matching within the Bipolar (BJT) NPN transistor category. The substitution criteria are:

Critical Matching Parameters:

• Transistor Type: NPN
• Current - Collector (Ic) (Max): 4 A
• Voltage - Collector Emitter Breakdown (Max): 400 V
• Mounting Type: Through Hole
• Package / Case: TO-220-3 Full Pack
• Operating Temperature (TJ): 150°C

Acceptable Variation Parameters:

• Power - Max: Equal to or greater than 28 W
• DC Current Gain (hFE): Variation permitted based on application requirements
• Vce Saturation: Variation permitted within switching performance tolerances

The FJPF3305H1TU from onsemi meets all critical matching parameters and demonstrates electrical compatibility for direct substitution in applications previously utilizing the STL128DNFP.

Parameter Comparison

Engineering Selection Recommendations

Both the STL128DNFP and FJPF3305H1TU are classified as obsolete products. The FJPF3305H1TU is suitable as a direct substitute based on the following factors:

Electrical Compatibility: The FJPF3305H1TU matches all critical electrical parameters including 4 A maximum collector current, 400 V collector-emitter breakdown voltage, and 150°C maximum junction temperature. The substitute provides 30 W maximum power dissipation, exceeding the 28 W requirement of the original part.

Regulatory Compliance: Both parts maintain ROHS3 compliance and REACH unaffected status, satisfying environmental and regulatory requirements for equivalent component selection.

Mechanical Compatibility: Both transistors utilize identical Through Hole mounting and TO-220-3 Full Pack packaging, ensuring direct physical compatibility in existing PCB layouts and thermal management designs.

Packaging Format: The FJPF3305H1TU is supplied in Tube packaging, whereas the original part number does not specify packaging format. Verify packaging requirements for your procurement and assembly processes.

Frequently Asked Questions (FAQ)

Q: Can the FJPF3305H1TU directly replace the STL128DNFP in existing applications?

A: Yes. The FJPF3305H1TU meets all critical electrical parameters (4 A collector current, 400 V breakdown voltage, 150°C operating temperature) and shares identical Through Hole TO-220-3 Full Pack packaging. Direct substitution is supported for applications previously utilizing the STL128DNFP.

Q: What are the key differences between these two transistors?

A: The primary differences are manufacturer (STMicroelectronics versus onsemi), maximum power dissipation (28 W versus 30 W), DC current gain specifications, and transition frequency (not specified for STL128DNFP versus 4 MHz for FJPF3305H1TU). Both transistors share identical voltage and current ratings.

Q: Are there packaging considerations when substituting the FJPF3305H1TU for the STL128DNFP?

A: Both parts use Through Hole TO-220-3 Full Pack packaging, ensuring mechanical and thermal compatibility. The FJPF3305H1TU is supplied in Tube packaging format. Confirm your assembly process accommodates tube-packaged components.

Q: Do both parts meet current environmental and regulatory standards?

A: Yes. Both the STL128DNFP and FJPF3305H1TU are ROHS3 compliant and REACH unaffected, satisfying current environmental regulations for electronic component manufacturing and use.

Q: Why is the STL128DNFP classified as obsolete?

A: The STL128DNFP is an older generation Bipolar (BJT) transistor no longer in active production by STMicroelectronics. Obsolete status indicates the manufacturer has discontinued this part number. The FJPF3305H1TU, also obsolete, represents an equivalent alternative from another manufacturer for legacy system support.

Q: What should be verified before implementing the FJPF3305H1TU as a substitute?

A: Verify that your application circuit design accommodates the electrical characteristics of the substitute part, particularly DC current gain (hFE) specifications and saturation voltage performance. Confirm PCB layout and thermal management design are compatible with TO-220-3 Full Pack packaging. Validate that procurement and assembly processes support Tube packaging format.