SS39 Schottky Diode Equivalent & Substitute Parts

Part Overview

The SS39 is a Schottky rectifier diode manufactured by onsemi, rated for 90 V DC reverse voltage and 3 A average rectified current in a surface mount SMC (DO-214AB) package. This component is classified as "Not For New Designs," indicating it has reached end-of-life status. Identifying equivalent and substitute parts is necessary for design continuity, legacy system support, and procurement flexibility when the primary part becomes unavailable.

Key Parameters

Parameter	Value	Unit
Voltage - DC Reverse (Vr) (Max)	90	V
Current - Average Rectified (Io)	3	A
Voltage - Forward (Vf) (Max) @ If	850 mV @ 3 A	mV
Speed	Fast Recovery ≤ 500ns, > 200mA (Io)	ns
Current - Reverse Leakage @ Vr	500	µA @ 90 V
Mounting Type	Surface Mount	—
Package / Case	DO-214AB, SMC	—
Operating Temperature - Junction	-55 to 150	°C
Technology	Schottky	—
RoHS Status	ROHS3 Compliant	—

Substitute Part Grouping Explanation

Substitution of the SS39 is determined by the following critical electrical and mechanical parameters:

Voltage Rating: The SS39 operates at 90 V maximum reverse voltage. Substitute parts must meet or exceed this voltage specification to ensure safe operation in the original circuit. Parts rated at 100 V are directly compatible and provide additional voltage margin.

Current Rating: The 3 A average rectified current is a primary selection criterion. Substitute parts must support at least 3 A continuous current. Parts rated higher (such as 6 A) are acceptable for applications where current headroom is beneficial.

Forward Voltage Drop: The SS39 exhibits 850 mV forward voltage at 3 A. Substitute parts with forward voltage specifications between 790 mV and 850 mV at 3 A are electrically compatible, as this parameter affects power dissipation and circuit efficiency within acceptable tolerances.

Package and Mounting: All substitute parts must use the DO-214AB (SMC) surface mount package to ensure mechanical and thermal compatibility with the original PCB layout.

Speed Characteristic: Fast recovery time (≤ 500ns for currents > 200mA) is maintained across all substitute options, ensuring switching performance consistency.

Temperature Range: The SS39 operates from -55°C to 150°C. Substitute parts with equal or wider temperature ranges are acceptable.

Parameter Comparison

Part Number	Manufacturer	Vr (Max) [V]	Io [A]	Vf (Max) @ If [mV]	Reverse Leakage @ Vr [µA]	Package	Temp Range [°C]	Product Status	RoHS Status
SS39	onsemi	90	3	850 @ 3A	500 @ 90V	DO-214AB, SMC	-55 to 150	Not For New Designs	ROHS3 Compliant
MBRS3100T3G	onsemi	100	3	790 @ 3A	50 @ 100V	DO-214AB, SMC	-65 to 175	Active	ROHS3 Compliant
NRVBS3100T3G	onsemi	100	3	790 @ 3A	50 @ 100V	DO-214AB, SMC	-65 to 175	Active	ROHS3 Compliant
B3100-13-F	Diodes Incorporated	100	3	790 @ 3A	500 @ 100V	DO-214AB, SMC	-55 to 125	Active	ROHS3 Compliant
B390-13-F	Diodes Incorporated	90	3	790 @ 3A	500 @ 90V	DO-214AB, SMC	-55 to 125	Active	ROHS3 Compliant
B390Q-13-F	Diodes Incorporated	90	3	790 @ 3A	500 @ 90V	DO-214AB, SMC	-55 to 125	Active	ROHS3 Compliant
HSM3100J/TR13	Microchip Technology	100	3	810 @ 3A	100 @ 100V	DO-214AB, SMC	-55 to 175	Active	RoHS non-compliant
HSM390J/TR13	Microchip Technology	90	3	810 @ 3A	100 @ 90V	DO-214AB, SMC	-55 to 175	Active	RoHS non-compliant
SK310-TP	Micro Commercial Co	100	3	850 @ 3A	500 @ 100V	DO-214AB, SMC	-55 to 150	Active	ROHS3 Compliant
SK610L-TP	Micro Commercial Co	100	6	850 @ 6A	1000 @ 100V	DO-214AB, SMC	-55 to 150	Active	Not specified
SS3H9-E3/57T	Vishay General Semiconductor - Diodes Division	90	3	800 @ 3A	20 @ 90V	DO-214AB, SMC	-65 to 175	Active	ROHS3 Compliant

Engineering Selection Recommendations

Direct Voltage-Matched Substitutes (90 V Rating):

The B390-13-F, B390Q-13-F, HSM390J/TR13, and SS3H9-E3/57T are direct electrical equivalents to the SS39, maintaining the 90 V reverse voltage specification. These parts are all in Active product status, ensuring long-term availability and supply chain stability. B390-13-F and B390Q-13-F are ROHS3 compliant. B390Q-13-F carries AEC-Q101 automotive qualification, suitable for applications requiring automotive-grade reliability. SS3H9-E3/57T offers the lowest reverse leakage current (20 µA @ 90 V) and the widest operating temperature range (-65°C to 175°C), providing superior performance characteristics for demanding applications.

Higher Voltage Substitutes (100 V Rating):

The MBRS3100T3G, NRVBS3100T3G, B3100-13-F, HSM3100J/TR13, and SK310-TP provide 100 V reverse voltage ratings, offering 10 V additional voltage margin over the original SS39 specification. These parts are electrically compatible with the SS39 in applications where the circuit can tolerate higher voltage ratings. MBRS3100T3G and NRVBS3100T3G are onsemi products in Active status with ROHS3 compliance and extended temperature ranges (-65°C to 175°C). B3100-13-F is a Diodes Incorporated product with ROHS3 compliance. SK310-TP matches the SS39 forward voltage characteristic (850 mV @ 3 A) and operating temperature range (-55°C to 150°C), providing the closest electrical performance profile.

Higher Current Substitute (6 A Rating):

The SK610L-TP is rated for 6 A average rectified current at 100 V reverse voltage. This part is suitable for applications where the original 3 A rating is marginal or where future current headroom is required. The higher current rating does not preclude use in 3 A circuits; however, thermal management and PCB layout considerations apply.

Compliance Considerations:

All recommended substitutes except HSM3100J/TR13 and HSM390J/TR13 are ROHS3 compliant, matching the original SS39 compliance status. The Microchip parts (HSM series) are RoHS non-compliant and should be selected only when legacy system requirements or specific design constraints mandate their use.

Frequently Asked Questions (FAQ)

Q: Can I use a 100 V rated diode in place of the 90 V SS39?

A: Yes. A 100 V rated diode is electrically compatible with the SS39 in any application designed for 90 V operation. The higher voltage rating provides additional safety margin and does not degrade circuit performance. The diode will not conduct at lower voltages than the original part.

Q: What is the difference between MBRS3100T3G and NRVBS3100T3G?

A: Both parts are onsemi 100 V, 3 A Schottky diodes with identical electrical specifications. They differ only in part number designation and internal product line classification. Either part is suitable as a substitute for the SS39.

Q: Is the B390Q-13-F suitable for automotive applications?

A: Yes. The B390Q-13-F carries AEC-Q101 automotive qualification, indicating it meets automotive reliability and testing standards. This part is recommended for automotive and mission-critical applications requiring formal qualification documentation.

Q: Why does the SS3H9-E3/57T have lower reverse leakage current than the SS39?

A: Reverse leakage current is a manufacturing and design characteristic that varies between manufacturers and product lines. The SS3H9-E3/57T exhibits 20 µA @ 90 V compared to the SS39's 500 µA @ 90 V. Lower leakage current reduces standby power dissipation and is beneficial in low-power or battery-powered applications.

Q: Can I use the SK610L-TP (6 A) in a circuit designed for the SS39 (3 A)?

A: Yes. The SK610L-TP is rated for 6 A and will operate safely in a 3 A circuit. The higher current rating does not affect circuit operation at lower currents. However, verify that the PCB thermal design and component placement accommodate the SK610L-TP's physical dimensions and thermal characteristics.

Q: What is the significance of the operating temperature range difference between the SS39 (-55°C to 150°C) and MBRS3100T3G (-65°C to 175°C)?

A: The MBRS3100T3G supports operation at lower minimum temperatures (-65°C versus -55°C) and higher maximum temperatures (175°C versus 150°C). This wider range is beneficial for applications exposed to extreme environmental conditions or high-temperature circuit environments. For standard industrial applications within -55°C to 150°C, both parts are equivalent.

Q: Are all substitute parts available in the same packaging options as the SS39?

A: All listed substitute parts use the DO-214AB (SMC) surface mount package, ensuring mechanical compatibility with the original SS39 PCB layout. Packaging options (Cut Tape, Tape & Reel, Bulk) vary by supplier and part number but do not affect electrical or mechanical compatibility.

Q: What does "Not For New Designs" mean for the SS39?

A: This designation indicates the SS39 has reached end-of-life status and onsemi no longer recommends it for new product designs. Existing inventory may remain available, but long-term supply is not guaranteed. Selecting an Active substitute part ensures design continuity and future procurement reliability.

Q: How do I determine which substitute is best for my application?

A: Evaluate substitutes based on: (1) voltage rating requirement (90 V or 100 V), (2) current rating requirement (3 A or higher), (3) forward voltage drop tolerance, (4) operating temperature range, (5) compliance requirements (RoHS status), and (6) long-term availability (Active product status). For most applications, MBRS3100T3G, B390-13-F, or SS3H9-E3/57T are recommended due to Active status and full compliance.

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