Taiwan Semiconductor Corporation SK315B

Overview

SK315B from Taiwan Semiconductor is a 3A, 150V Schottky barrier surface-mount rectifier in DO-214AA (SMB) package, optimized for high-efficiency switching power supplies with low forward voltage (0.95 V at 3 A, 25°C), high surge current capability (70 A), and junction temperature up to +150°C. It serves as a primary output rectifier in AC/DC adapters and DC/DC converters.

For engineers reviewing the SK315B datasheet, SK315B pinout, SK315B application, or SK315B equivalent, key selection criteria include its 150 V repetitive peak reverse voltage, 0.95 V forward voltage at rated current, 70 A non-repetitive surge rating, thermal resistance (R_θJL = 23°C/W), and RoHS/halogen-free compliance for industrial and consumer power designs.

Technical Context

The SK315B is a single-die, unidirectional Schottky rectifier with cathode band polarity indication and guard ring structure for enhanced overvoltage robustness. Its low forward voltage drop minimizes conduction losses, while its 10,000 V/μs critical dV/dt rating supports reliable operation in fast-switching topologies.

Designed for surface-mount assembly on PCBs, it meets J-STD-020 moisture sensitivity level 1 and JESD 201 class 2 whisker resistance. The DO-214AA (SMB) package enables automated placement and provides 63°C/W junction-to-ambient thermal resistance under standard board conditions.

Key Specifications

Pinout & Package

DO-214AA (SMB) surface-mount package: molded plastic body (UL 94V-0), matte tin-plated leads, cathode indicated by band. Weight ≈ 0.100 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SS3H15 and SB3150, the SK315B offers balanced performance: higher VF than SS3H15 but lower unit cost; lower thermal resistance than SB3150, enabling better power density in space-constrained adapters and LED drivers.

Availability

SK315B is available at Aetrix Electronics and suitable for AC/DC adapters, LED drivers, and industrial DC/DC converters requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for SK315B 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 rectifiers, TVS diodes, and MOSFETs since 1979.

The SK3xB series was developed specifically for high-volume, cost-sensitive switching power applications demanding reliable Schottky performance in standard SMB packaging with extended temperature and surge robustness.

FAQ

What is the maximum junction temperature rating for the SK315B?

The SK315B has a maximum junction temperature (T_J) rating of +150°C, verified per absolute maximum ratings table in the official TSC datasheet P2212. This allows sustained operation in thermally demanding environments such as enclosed LED drivers or high-density AC/DC adapters. Derating begins above 25°C ambient, with average forward current reduced linearly to zero at 150°C junction temperature. The SK315B must be mounted on PCB copper area sufficient to maintain T_J ≤ 150°C under worst-case load and ambient conditions.

Does the SK315B have a guard ring structure, and what benefit does it provide?

Yes, the SK315B incorporates a guard ring structure explicitly stated in its features list. This design enhances edge termination robustness, improving resistance to localized avalanche breakdown during transient overvoltage events-such as line surges or transformer reset spikes-without requiring external clamping components. The guard ring contributes directly to the device's specified 10,000 V/μs dV/dt rating and enables reliable operation in unclamped flyback and forward converter topologies where voltage overshoot is common.

What is the forward voltage specification for SK315B at 3 A and 100°C junction temperature?

The SK315B datasheet specifies forward voltage only at T_J = 25°C (0.95 V max). No guaranteed V_F value is provided at 100°C; however, typical curves (Fig.10) show V_F increases to approximately 0.85 V at 3 A and 100°C. Designers should use the 25°C max value for worst-case conduction loss calculation and verify thermal design ensures actual T_J remains within limits. The SK315B's V_F temperature coefficient is negative, meaning voltage drop decreases slightly with rising temperature-a characteristic of Schottky diodes.

Is the SK315B suitable for use in automotive applications?

No, the SK315B is not qualified for automotive applications. Taiwan Semiconductor explicitly states in the product notice (page 8, P2212) that "The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications." It lacks AEC-Q101 qualification, automotive-grade screening, and extended temperature range beyond +150°C junction. For automotive 12 V systems requiring 3 A/150 V rectification, designers should select AEC-Q101-certified alternatives such as STMicroelectronics STPS3150CG or Diodes Incorporated SB3150-E3/54.

What is the moisture sensitivity level (MSL) and reflow profile compatibility for SK315B?

The SK315B has moisture sensitivity level (MSL) 1 per J-STD-020, meaning it is not humidity-sensitive and requires no baking prior to surface-mount reflow. It is fully compatible with standard lead-free reflow profiles (e.g., IPC/JEDEC J-STD-020D), including peak temperatures up to 260°C. The matte tin-plated leads meet J-STD-002 solderability requirements, and the DO-214AA (SMB) package is optimized for automated pick-and-place. No special handling or dry pack is needed for SK315B storage or assembly.