SS34L MHG Equivalent & Substitute Parts

Part Overview

The SS34L MHG is an active Schottky rectifier diode manufactured by Taiwan Semiconductor Corporation, designed for surface mount applications in the Sub SMA package format. This component operates at a maximum reverse voltage of 40 V with an average rectified current rating of 3 A and exhibits fast recovery characteristics suitable for high-frequency switching applications. The part is ROHS3 compliant and carries unlimited moisture sensitivity classification, indicating robust handling characteristics for standard manufacturing environments. Substitute parts are identified to address inventory availability, extended temperature range requirements, or specific automotive qualification needs while maintaining electrical and mechanical compatibility within the defined parameter envelope.

Substiute Parts

SS34L MHG

Taiwan Semiconductor CorporationIn Stock: 1033SS34L MHG Datasheet

Current PartRFQ

SS1FL4HM3/H

Vishay General Semiconductor - Diodes DivisionIn Stock: 33227SS1FL4HM3/H Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the SS34L MHG is permissible with the SS1FL4HM3/H based on the following electrical and mechanical compatibility criteria:

Matching Parameters:

• Voltage - DC Reverse (Vr) (Max): 40 V (identical)
• Technology: Schottky (identical)
• Speed: Fast Recovery ≤ 500ns, > 200mA (Io) (identical)
• Package / Case: DO-219AB (identical)
• Mounting Type: Surface Mount (identical)
• RoHS Status: ROHS3 Compliant (identical)
• Moisture Sensitivity Level (MSL): 1 (Unlimited) (identical)

Differing Parameters Requiring Evaluation:

• Current - Average Rectified (Io): SS34L MHG rated at 3 A; SS1FL4HM3/H rated at 1 A
• Operating Temperature - Junction: SS34L MHG rated -55 to 125°C; SS1FL4HM3/H rated -55 to 150°C
• Current - Reverse Leakage @ Vr: SS34L MHG at 500 µA @ 40 V; SS1FL4HM3/H at 200 µA @ 40 V

The SS1FL4HM3/H operates within the same voltage and package specifications as the SS34L MHG. However, the reduced current rating of 1 A versus 3 A restricts its application to circuits where the average rectified current does not exceed 1 A. The extended upper operating temperature of 150°C provides additional thermal margin. The lower reverse leakage current represents improved performance characteristics.

Parameter Comparison

Engineering Selection Recommendations

Primary Application Suitability:

The SS34L MHG remains the specified component for applications requiring the full 3 A average rectified current rating within the -55 to 125°C operating temperature range. This part is ROHS3 compliant and carries unlimited moisture sensitivity classification, suitable for standard manufacturing and field deployment.

Substitute Application Suitability:

The SS1FL4HM3/H (SS1FL4 base product) is suitable as a substitute only in applications where the average rectified current requirement does not exceed 1 A. This substitute provides identical voltage and package specifications, identical fast recovery speed characteristics, and ROHS3 compliance. The extended operating temperature range to 150°C and lower reverse leakage current (200 µA versus 500 µA) represent performance enhancements. The AEC-Q101 automotive qualification of the substitute indicates suitability for automotive-grade applications where such certification is required.

Compliance Considerations:

Both parts maintain ROHS3 compliance and unlimited moisture sensitivity classification. Both are classified under ECCN EAR99 and HTSUS 8541.10.0080. The substitute carries REACH Unaffected status, matching the main part specification.

Frequently Asked Questions (FAQ)

Q: Can the SS1FL4HM3/H directly replace the SS34L MHG in all applications?

A: Direct replacement is permissible only in applications where the average rectified current does not exceed 1 A. The SS34L MHG is rated for 3 A average rectified current, while the SS1FL4HM3/H is rated for 1 A. If the circuit design requires current handling above 1 A, the SS1FL4HM3/H will not function within its rated specifications.

Q: Are the package dimensions identical between these parts?

A: Both parts use the DO-219AB package format for surface mount applications. The mechanical footprint and land pattern are identical, permitting direct PCB layout compatibility without redesign.

Q: What is the significance of the different reverse leakage current specifications?

A: The SS1FL4HM3/H exhibits lower reverse leakage current (200 µA @ 40 V) compared to the SS34L MHG (500 µA @ 40 V). Lower reverse leakage reduces parasitic current draw in the reverse-biased state, which may improve circuit efficiency in applications sensitive to leakage current.

Q: Does the extended operating temperature range of the SS1FL4HM3/H affect compatibility?

A: The SS1FL4HM3/H operates from -55 to 150°C, while the SS34L MHG operates from -55 to 125°C. The extended upper temperature limit of the substitute provides additional thermal margin. If the application operates within the -55 to 125°C range of the main part, both components are compatible. If the application requires operation above 125°C, only the SS1FL4HM3/H is suitable.

Q: What does AEC-Q101 qualification indicate for the substitute part?

A: AEC-Q101 is an automotive industry qualification standard for discrete semiconductors. The SS1FL4HM3/H carries this qualification, indicating it meets automotive-grade reliability and performance requirements. The SS34L MHG does not list this qualification. If automotive-grade certification is a design requirement, the SS1FL4HM3/H is the appropriate selection.

Q: Are there any differences in forward voltage characteristics between these parts?

A: Both parts specify 500 mV maximum forward voltage. However, this specification is measured at different current levels: the SS34L MHG at 3 A and the SS1FL4HM3/H at 1 A. Forward voltage characteristics are current-dependent; direct comparison at identical current levels would require additional datasheet information not provided in the standard specifications.

Q: Can I use the SS1FL4HM3/H in a 3 A application if I parallel multiple devices?

A: Paralleling diodes introduces additional design complexity including current sharing considerations, thermal management, and potential reliability issues. This approach is outside the scope of direct component substitution and requires detailed circuit analysis and validation.