Taiwan Semiconductor Corporation SK32B R5G

Overview

SK32B from Taiwan Semiconductor is a 3A, 20V Schottky barrier surface-mount rectifier in DO-214AA (SMB) package, featuring low forward voltage (≤0.50 V at 3 A, 25°C), high surge current capability (70 A), and junction temperature rating up to +125°C. It serves as a primary output rectifier in compact AC/DC adapters and DC/DC converters.

For engineers reviewing the SK32B datasheet, SK32B pinout, SK32B application, or SK32B equivalent, key selection criteria include forward voltage drop at rated current, repetitive peak reverse voltage margin, thermal resistance (R_θJL = 23°C/W), surge robustness, and SMB package compatibility with automated SMT assembly.

Technical Context

The SK32B employs a single-die Schottky junction optimized for low conduction loss in medium-current switching applications. Its 20 V V_RRM rating targets secondary-side rectification where low forward voltage improves efficiency, while its 70 A I_FSM supports transient overload handling in flyback and buck-derived topologies.

Thermal performance is defined by R_θJL = 23°C/W and R_θJA = 63°C/W, enabling reliable operation at full 3 A DC current on standard 1 oz copper PCBs with minimal heatsinking. The device uses matte tin-plated leads compliant with J-STD-002 and meets JESD201 Class 2 whisker resistance.

Key Specifications

Pinout & Package

Package: DO-214AA (SMB), surface-mount, cathode indicated by band. Dimensions: 4.60 × 3.95 × 2.00 mm (L × W × H). Weight: 0.100 g.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Schottky rectifier applications.

Compared with SS32 and SB320, the SK32B offers superior thermal resistance and highest surge current rating in the 20 V/3 A SMB-class Schottky segment-making it optimal for thermally constrained or high-reliability industrial adapters.

Availability

SK32B is available at Aetrix Electronics and suitable for AC/DC adapters, LED drivers, and industrial DC/DC converters requiring stable component supply, consistent lead-time visibility, and long-term production continuity.

Supply support for SK32B includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in power devices, rectifiers, and protection components since 1979.

The SK32B belongs to TSC's SK3xB Schottky rectifier family, engineered specifically for high-efficiency, space-constrained switching power supplies where low forward voltage and robust surge handling are critical design requirements.

FAQ

What is the maximum junction temperature for the SK32B?

The SK32B has a maximum junction temperature (T_J) of +125°C under continuous operation. This rating applies across the full operating current range and enables use in sealed enclosures without forced airflow. Derating begins above this temperature, and the device must not exceed 125°C at the die to maintain reliability per the datasheet's absolute maximum ratings table. The SK32B is not rated for 150°C operation-only higher-voltage variants like SK310B and SK320B support that extended range.

Does the SK32B have a guard ring, and why does it matter?

Yes, the SK32B incorporates a guard ring structure explicitly noted in its features list. This design element mitigates electric field crowding at the semiconductor junction edge, preventing premature avalanche breakdown during voltage transients. In practice, this enhances reliability in unregulated or loosely regulated SMPS where line surges or output overvoltage events may occur-reducing field failure risk without requiring external TVS clamping.

Is the SK32B RoHS and halogen-free compliant?

Yes, the SK32B is RoHS compliant and halogen-free per IEC 61249-2-21. The molding compound contains no brominated or chlorinated flame retardants, and all homogeneous materials meet EU Directive 2011/65/EU restrictions. This compliance is confirmed in the "Features" section of the official TSC datasheet (Version P2212) and supports export to EU, Japan, and other regulated markets without material declaration exceptions.

What is the reverse leakage current of the SK32B at 100°C?

At T_J = 100°C and rated reverse voltage (20 V), the SK32B exhibits a maximum reverse leakage current (I_R) of 10 mA. This value is specified in the Electrical Specifications table under Note 2 (30 ms pulse test). While higher than room-temperature leakage (500 µA max), this level remains acceptable for most adapter and converter applications where thermal design keeps average junction temperature below 100°C.

Can the SK32B replace a 1N5822 in an existing design?

Yes, the SK32B can serve as a functional replacement for the 1N5822 in many cases: both are 3 A, 20 V Schottky rectifiers in DO-214AA (SMB) packages with cathode-band polarity marking. However, the SK32B has lower V_F (≤0.50 V vs. ≤0.55 V) and higher I_FSM (70 A vs. 60 A), offering improved efficiency and surge margin. Layout and soldering profiles remain identical-no PCB changes are needed.