STLD128DNT4 Equivalent & Substitute Parts

Part Overview

The STLD128DNT4 is an NPN bipolar junction transistor manufactured by STMicroelectronics, rated for 400 V collector-emitter breakdown voltage and 4 A maximum collector current. This surface mount device is packaged in DPAK (TO-252-3) configuration with a maximum power dissipation of 20 W. The part is currently in Active product status with 3700 units in stock.

Substitute parts are necessary when the STLD128DNT4 becomes unavailable, reaches end-of-life status, or when design requirements necessitate alternative electrical or thermal characteristics within the same functional category. The substitute parts listed maintain compatibility with the DPAK surface mount package and preserve the core voltage and current ratings required for standard switching applications.

Substiute Parts

STLD128DNT4

STMicroelectronicsIn Stock: 3715STLD128DNT4 Datasheet

Current PartRFQ

FJD3305H1TM

onsemiIn Stock: 3575FJD3305H1TM Datasheet

DirectRFQ

FJD5304DTF

onsemiIn Stock: 2042FJD5304DTF Datasheet

DirectRFQ

FJD5553TM

onsemiIn Stock: 15326FJD5553TM Datasheet

SimilarRFQ

FJD5555TM

onsemiIn Stock: 5194FJD5555TM Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the STLD128DNT4 is determined by the following critical parameters:

Primary Compatibility Criteria:

• Transistor Type: NPN
• Voltage - Collector Emitter Breakdown (Max): 400 V minimum
• Current - Collector (Ic) (Max): 4 A minimum
• Package / Case: TO-252-3, DPAK (2 Leads + Tab), SC-63
• Mounting Type: Surface Mount
• Operating Temperature: 150°C (TJ) minimum

Substitution Categories:

Direct Substitutes maintain all primary compatibility criteria with equivalent or superior electrical ratings:

• FJD5304DTF: Matches 400 V, 4 A ratings with 30 W power rating (exceeds 20 W requirement)
• FJD3305H1TM: Matches 400 V, 4 A ratings with reduced power rating (1.1 W)

Similar Substitutes maintain voltage and package compatibility but differ in current rating:

• FJD5553TM: 400 V rated, 3 A maximum collector current (below 4 A requirement)
• FJD5555TM: 400 V rated, 5 A maximum collector current (exceeds 4 A requirement)

All substitute parts are ROHS3 compliant, REACH unaffected, and rated for 150°C maximum junction temperature, matching the compliance profile of the main part.

Parameter Comparison

Engineering Selection Recommendations

FJD5304DTF is the primary direct substitute for the STLD128DNT4. This onsemi part maintains identical voltage (400 V) and current (4 A) ratings while providing superior power dissipation capability (30 W versus 20 W). The FJD5304DTF is in Active product status, ensuring long-term availability. Both parts are ROHS3 compliant and REACH unaffected, with matching MSL ratings and identical package specifications.

FJD3305H1TM is a direct electrical substitute matching the 400 V and 4 A specifications. However, this part carries Last Time Buy status, indicating limited future availability. The significantly reduced power rating (1.1 W) restricts its application to low-power switching scenarios. Selection of this part should be limited to applications where thermal dissipation requirements are minimal.

FJD5553TM and FJD5555TM are similar substitutes suitable only for applications where the collector current requirement can be adjusted. FJD5553TM is rated for 3 A maximum, making it unsuitable for circuits requiring the full 4 A capability of the STLD128DNT4. FJD5555TM is rated for 5 A maximum, providing current margin for applications requiring up to 4 A. Both parts are in Active status with ROHS3 compliance.

For new designs and long-term production requirements, FJD5304DTF is the recommended substitute. For applications with reduced power dissipation needs, FJD3305H1TM remains compatible but should be evaluated for end-of-life planning. Current-limited applications may utilize FJD5553TM or FJD5555TM with appropriate circuit verification.

Frequently Asked Questions (FAQ)

Q: Can FJD3305H1TM replace STLD128DNT4 in all applications?

A: FJD3305H1TM maintains the same voltage (400 V) and current (4 A) ratings as the STLD128DNT4. However, the significantly lower power rating (1.1 W versus 20 W) restricts its use to low-power switching applications. Applications requiring sustained power dissipation above 1.1 W require thermal analysis before substitution. Additionally, FJD3305H1TM carries Last Time Buy status, limiting future availability.

Q: What is the difference between direct and similar substitutes?

A: Direct substitutes (FJD5304DTF, FJD3305H1TM) maintain the same maximum collector current rating (4 A) as the STLD128DNT4. Similar substitutes (FJD5553TM, FJD5555TM) differ in collector current rating. FJD5553TM is rated for 3 A maximum, while FJD5555TM is rated for 5 A maximum. Selection depends on the specific current requirements of the application circuit.

Q: Are all substitute parts available in the same packaging?

A: Yes. All substitute parts listed are packaged in TO-252-3 DPAK (2 Leads + Tab) configuration, identical to the STLD128DNT4. All parts are surface mount devices suitable for automated assembly processes. Tape & Reel and Cut Tape packaging options vary by part number but do not affect electrical compatibility.

Q: Which substitute offers the best thermal performance?

A: FJD5304DTF provides the highest power dissipation rating at 30 W, exceeding the STLD128DNT4 specification of 20 W. This additional thermal margin is beneficial for applications operating at elevated ambient temperatures or with continuous current loading. FJD5304DTF is in Active product status, ensuring availability for long-term production.

Q: Are compliance certifications identical across all parts?

A: All listed parts are ROHS3 compliant, REACH unaffected, and carry MSL rating of 1 (Unlimited). Moisture sensitivity and regulatory compliance are equivalent across the STLD128DNT4 and all substitute parts, eliminating compliance-related substitution barriers.

Q: What is the significance of product status in substitution decisions?

A: STLD128DNT4 and FJD5304DTF are in Active status, indicating ongoing manufacturing and long-term availability. FJD3305H1TM carries Last Time Buy status, signaling limited production and eventual discontinuation. FJD5553TM and FJD5555TM are in Active status. For new designs and production planning, Active status parts are preferred to ensure supply continuity.

Q: Can FJD5555TM be used in place of STLD128DNT4?

A: FJD5555TM is electrically compatible with the STLD128DNT4 for applications requiring up to 4 A collector current. The 5 A maximum rating provides current margin. However, the significantly lower power rating (1.34 W versus 20 W) restricts thermal capability. Circuit verification is required to confirm that power dissipation remains within the 1.34 W limit during normal operation.

Q: What parameters must remain constant for substitution?

A: The following parameters must remain constant or be exceeded: Transistor Type (NPN), Voltage - Collector Emitter Breakdown (400 V minimum), Current - Collector (4 A minimum for direct substitutes), Package / Case (TO-252-3 DPAK), and Mounting Type (Surface Mount). Deviations in these parameters require full circuit re-evaluation and are not considered direct substitutions.