SK35B-LTP Equivalent & Substitute Parts

Part Overview

The SK35B-LTP is a Schottky rectifier diode manufactured by Micro Commercial Co, rated for 50 V DC reverse voltage and 3 A average rectified current in a DO-214AA (SMB) surface mount package. This component is classified as "Not For New Designs," indicating it has reached end-of-life status. Equivalent and substitute parts are necessary to support existing designs, provide design flexibility, and ensure supply chain continuity for applications requiring Schottky diode functionality in this voltage and current class.

Key Parameters

Parameter	Value	Unit
Voltage - DC Reverse (Vr) (Max)	50	V
Current - Average Rectified (Io)	3	A
Voltage - Forward (Vf) (Max) @ If	750 mV @ 3 A	mV
Speed	Fast Recovery ≤ 500ns, > 200mA (Io)	ns
Current - Reverse Leakage @ Vr	500	µA @ 50 V
Mounting Type	Surface Mount	—
Package / Case	DO-214AA, SMB	—
Operating Temperature - Junction	-55 to 150	°C
Technology	Schottky	—
RoHS Status	ROHS3 Compliant	—

Substitute Part Grouping Explanation

Substitution of the SK35B-LTP is determined by the following critical parameters:

Voltage Rating: The reverse voltage rating must equal or exceed 50 V to maintain circuit protection and reliability margins.

Current Rating: The average rectified current must equal or exceed 3 A to handle the design load without thermal stress or performance degradation.

Package Type: All substitutes must use DO-214AA (SMB) surface mount packaging to ensure mechanical and electrical compatibility with existing PCB layouts.

Technology: Schottky diode technology is required to maintain fast recovery characteristics and forward voltage performance.

Speed Characteristics: Fast recovery with switching time ≤ 500 ns at currents > 200 mA is necessary for high-frequency rectification applications.

Substitute parts are grouped into two categories:

Category A - Full Equivalents (50 V, 2-3 A): Parts meeting or exceeding all primary electrical parameters of the SK35B-LTP, suitable for direct replacement without circuit modification.

Category B - Reduced Voltage Substitutes (40 V, 1-3 A): Parts with lower reverse voltage ratings (40 V instead of 50 V), applicable only in circuits where the 40 V rating provides adequate safety margin for the actual operating voltage.

Parameter Comparison

Part Number	Manufacturer	Vr (Max)	Io (A)	Vf (Max)	Ir @ Vr	Package	Product Status	Temp Range
SK35B-LTP	Micro Commercial Co	50 V	3	750 mV @ 3 A	500 µA @ 50 V	DO-214AA, SMB	Not For New Designs	-55 to 150°C
B250-13-F	Diodes Incorporated	50 V	2	700 mV @ 2 A	500 µA @ 50 V	DO-214AA, SMB	Active	-65 to 150°C
SS25	Taiwan Semiconductor Corporation	50 V	2	700 mV @ 2 A	400 µA @ 50 V	DO-214AA, SMB	Active	-55 to 150°C
B150B-13-F	Diodes Incorporated	50 V	1	700 mV @ 1 A	500 µA @ 50 V	DO-214AA, SMB	Active	-65 to 150°C
STPS140U	STMicroelectronics	40 V	1	550 mV @ 1 A	12 µA @ 40 V	DO-214AA, SMB	Active	—
STPS140UY	STMicroelectronics	40 V	1	650 mV @ 2 A	12 µA @ 40 V	DO-214AA, SMB	Active	-40 to 150°C
STPS1L40U	STMicroelectronics	40 V	1	500 mV @ 1 A	35 µA @ 40 V	DO-214AA, SMB	Active	—
STPS1L40UY	STMicroelectronics	40 V	1	500 mV @ 1 A	35 µA @ 40 V	DO-214AA, SMB	Active	-40 to 150°C
STPS2L40U	STMicroelectronics	40 V	2	430 mV @ 2 A	220 µA @ 40 V	DO-214AA, SMB	Active	—
STPS340U	STMicroelectronics	40 V	3	630 mV @ 3 A	20 µA @ 40 V	DO-214AA, SMB	Active	—
STPS340UY	STMicroelectronics	40 V	3	630 mV @ 3 A	20 µA @ 40 V	DO-214AA, SMB	Active	-40 to 150°C

Engineering Selection Recommendations

Primary Substitutes (50 V Rating - Recommended for Direct Replacement):

The B250-13-F and SS25 are the preferred substitutes for the SK35B-LTP. Both maintain the 50 V reverse voltage rating and provide 2 A current capacity. The B250-13-F is manufactured by Diodes Incorporated with Active product status and ROHS3 compliance. The SS25 is manufactured by Taiwan Semiconductor Corporation, also with Active status and ROHS3 compliance. Both parts are available in high inventory quantities and support existing circuit designs without modification.

The B150B-13-F is a 50 V, 1 A substitute suitable only for applications where the design current requirement does not exceed 1 A. This part is manufactured by Diodes Incorporated with Active status and extended temperature range (-65 to 150°C).

Secondary Substitutes (40 V Rating - Application-Dependent):

The STMicroelectronics STPS series parts (STPS140U, STPS140UY, STPS1L40U, STPS1L40UY, STPS2L40U, STPS340U, STPS340UY) operate at 40 V reverse voltage. These parts are suitable only for circuits where the maximum operating voltage does not exceed 40 V and where a 10 V margin below the rated reverse voltage is acceptable. All STPS parts maintain Active product status and ROHS3 compliance.

The STPS340U and STPS340UY provide 3 A current capacity at 40 V, matching the current rating of the SK35B-LTP. The STPS340UY variant includes Automotive grade qualification (AEC-Q101) and extended temperature range (-40 to 150°C), suitable for automotive applications.

Compliance and Regulatory Status:

All substitute parts listed are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements. All parts maintain fast recovery characteristics (≤ 500 ns) and Schottky technology specifications consistent with the original SK35B-LTP.

Frequently Asked Questions (FAQ)

Q: Can the B150B-13-F replace the SK35B-LTP in all applications?

A: No. The B150B-13-F is rated for 1 A average rectified current, while the SK35B-LTP is rated for 3 A. The B150B-13-F is suitable only for applications where the design current does not exceed 1 A. Using an undersized current rating will result in excessive junction temperature and reduced component reliability.

Q: What is the difference between the 50 V and 40 V substitute options?

A: The 50 V substitutes (B250-13-F, SS25, B150B-13-F) maintain the same reverse voltage rating as the SK35B-LTP and are suitable for direct replacement in any circuit. The 40 V substitutes (STPS series) have a lower reverse voltage rating and are suitable only for circuits where the maximum operating voltage does not exceed 40 V. Using a 40 V part in a circuit designed for 50 V operation may result in diode failure.

Q: Are the STPS automotive-grade parts (STPS140UY, STPS1L40UY, STPS340UY) interchangeable with the standard STPS parts?

A: The automotive-grade variants (designated with "UY" suffix) include AEC-Q101 qualification and extended temperature range (-40 to 150°C). They are electrically and mechanically compatible with standard STPS parts but provide additional qualification for automotive applications. The automotive variants may be used in non-automotive applications without issue.

Q: Does the SK35B-LTP "Not For New Designs" status affect substitute selection?

A: Yes. The "Not For New Designs" status indicates the SK35B-LTP is end-of-life. For new designs, select from the Active status substitutes: B250-13-F, SS25, B150B-13-F, or the STPS series parts. For existing designs using SK35B-LTP, any of the listed substitutes with matching electrical parameters are acceptable for replacement.

Q: Can I use the SS25 in place of the B250-13-F?

A: Yes. Both the SS25 and B250-13-F are rated for 50 V and 2 A, use DO-214AA (SMB) packaging, and maintain fast recovery characteristics. The SS25 has slightly lower reverse leakage current (400 µA vs. 500 µA at 50 V) and identical forward voltage characteristics. Both parts are suitable for direct substitution.

Q: What is the significance of the forward voltage (Vf) differences between substitutes?

A: Forward voltage differences affect power dissipation and circuit efficiency. The SK35B-LTP has Vf of 750 mV @ 3 A. The B250-13-F and SS25 have lower Vf (700 mV @ 2 A), resulting in reduced power loss. The STPS series parts have significantly lower Vf values (430-650 mV depending on model), providing improved efficiency but only at 40 V rating. Forward voltage differences of 50-100 mV are typical across Schottky diode families and do not affect circuit functionality.

Q: Is the DO-214AA package identical to SMB?

A: Yes. DO-214AA and SMB (Surface Mount Body) refer to the same physical package. Both designations describe a surface mount rectifier package with identical dimensions and pin configuration. All substitute parts listed use this package and are mechanically compatible with SK35B-LTP PCB layouts.

Q: What is the difference between Cut Tape (CT) and Tape & Reel (TR) packaging?

A: Cut Tape and Tape & Reel are supply formats, not component package types. Both formats contain the same DO-214AA (SMB) component. Tape & Reel is used for high-volume automated assembly, while Cut Tape is used for lower-volume or manual assembly. The electrical and mechanical specifications are identical regardless of supply format.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message