Taiwan Semiconductor Corporation SK33A

Overview

SK33A from Taiwan Semiconductor is a 3A, 30V Schottky barrier surface-mount rectifier in DO-214AC (SMA) package, designed for high-efficiency DC/DC conversion with low forward voltage (0.55 V at 3 A, 25°C), high surge current capability (70 A), and junction temperature rating up to 150°C. It serves as a primary output rectifier in compact AC/DC adapters and offline SMPS.

For engineers reviewing the SK33A datasheet, SK33A pinout, SK33A application, or SK33A equivalent, key selection criteria include its 30 V repetitive peak reverse voltage, 0.55 V forward voltage at rated current, 70 A non-repetitive surge rating, thermal resistance (R_θJL = 25°C/W), and RoHS/halogen-free compliance for industrial power supply design.

Technical Context

The SK33A employs a single-die Schottky structure optimized for low conduction loss in medium-voltage switching applications. Its 30 V V_RRM, 3 A average forward current, and 10,000 V/µs dV/dt rating support fast-switching topologies including flyback and forward converters operating up to 150°C junction temperature.

Thermally, it features a junction-to-lead resistance of 25°C/W and junction-to-ambient resistance of 66°C/W under standard PCB mounting. Reverse leakage remains ≤500 µA at 25°C and ≤10 mA at 100°C, enabling stable operation in thermally constrained adapter designs.

Key Specifications

Pinout & Package

Package: DO-214AC (SMA), surface-mount, cathode indicated by band. Matte tin-plated leads, moisture sensitivity level 1 (J-STD-020), UL 94V-0 molding compound.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SS33 and SB330, the SK33A offers balanced trade-offs: identical voltage/current ratings, industry-standard thermal metrics, and guard-ring-enhanced ruggedness-making it especially suitable for cost-sensitive, thermally constrained adapter and lighting applications where reliability under surge stress is essential.

Availability

SK33A is available at Aetrix Electronics and suitable for AC/DC adapters, LED drivers, and industrial SMPS requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for SK33A 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, serving global power and protection markets since 1979.

The SK32A–SK320A family delivers standardized Schottky rectifiers from 20 V to 200 V, engineered specifically for high-volume, cost-optimized switching power supplies where efficiency, surge robustness, and JEDEC-compliant packaging are mandatory.

FAQ

What is the maximum junction temperature rating for the SK33A?

The SK33A has a maximum junction temperature (T_J) rating of +150°C, verified per absolute maximum ratings table in the official Taiwan Semiconductor datasheet (Version W2304). This allows the SK33A to operate reliably in sealed enclosures or high-ambient environments without derating below 3 A up to 100°C ambient, provided thermal design meets R_θJL = 25°C/W requirements. The SK33A's thermal specification is fully aligned with industrial-grade power supply standards.

Does the SK33A have a guard ring structure, and what benefit does it provide?

Yes, the SK33A incorporates a guard ring structure explicitly stated in its features list. This design enhances voltage standoff stability and protects against edge breakdown during transient overvoltage events. In practice, the guard ring improves V_RRM consistency across manufacturing lots and increases robustness in flyback and LLC converters subject to reflected voltage spikes-directly contributing to higher field reliability versus non-guarded Schottky rectifiers of similar rating.

What is the forward voltage of the SK33A at 3 A and 100°C junction temperature?

The SK33A datasheet specifies forward voltage only at 25°C (0.55 V max @ 3 A); no typ/max V_F value is published at 100°C. However, typical Schottky behavior shows V_F decreases ~2 mV/°C, so V_F at 100°C is estimated near 0.41 V. For design-critical applications, engineers should verify actual V_F using the SK33A's Fig.4 Typical Forward Characteristics curve or perform bench validation, as the SK33A's published specs do not guarantee performance beyond 25°C test conditions.

Is the SK33A halogen-free and RoHS compliant?

Yes, the SK33A is both halogen-free and RoHS compliant, as confirmed in the "FEATURES" section of the official Taiwan Semiconductor datasheet (Version W2304). These compliance statements are product-level declarations-not conditional on packaging or date code-and apply to all SK33A units shipped under this ordering code. Material content documentation (e.g., IPC-1752A) is available upon request from Aetrix Electronics for full supply chain traceability.

What is the moisture sensitivity level (MSL) of the SK33A, and how does it affect handling?

The SK33A has a moisture sensitivity level (MSL) of Level 1 per J-STD-020, meaning it is not humidity-sensitive and may be stored indefinitely at ambient conditions (<30°C / 60% RH) without baking or dry-pack requirements. This eliminates reflow preparation steps for automated assembly, reduces line downtime, and supports just-in-time manufacturing-making the SK33A ideal for high-throughput SMT lines producing adapters, chargers, and lighting products.