Taiwan Semiconductor Corporation SK59C

Overview

SK59C from Taiwan Semiconductor is a 5A, 90V Schottky barrier surface-mount rectifier in DO-214AB (SMC) package, optimized for high-efficiency switching power supplies with low forward voltage (0.85 V at 5 A, 25°C) and high surge capability (120 A, 8.3 ms). It operates from −55°C to +150°C and features guard-ring overvoltage protection.

For engineers reviewing the SK59C datasheet, SK59C pinout, SK59C application, or SK59C equivalent, key selection criteria include its 90 V repetitive peak reverse voltage, 0.85 V forward drop at rated current, 53 °C/W junction-to-ambient thermal resistance on standard PCB, and moisture sensitivity level 1 compliance - all critical for SMPS output rectification and DC-DC converter design.

Technical Context

The SK59C is a single-die, unidirectional Schottky rectifier with cathode-band polarity indication and matte tin-plated leads solderable per J-STD-002. Its 10,000 V/µs critical rate of rise of off-state voltage supports fast-switching topologies without spurious turn-on.

Thermally, it delivers 13 °C/W junction-to-lead resistance when mounted on a 16 mm × 16 mm copper pad, enabling reliable 5 A continuous conduction in compact layouts. The device exhibits 0.3 mA maximum reverse leakage at 25°C and 5 mA at 125°C under rated 90 V reverse bias.

Key Specifications

Pinout & Package

Package: DO-214AB (SMC), surface-mount plastic case with cathode band marking; dimensions 7.75 mm × 6.25 mm × 2.45 mm (L × W × H); weight ≈ 0.210 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VS-50SQ030 and SB590, the SK59C offers the optimal balance of 90 V blocking capability and 0.85 V forward voltage in DO-214AB, making it uniquely suited for mid-voltage (48–90 V) SMPS outputs where both voltage margin and conduction loss matter.

Availability

SK59C is available at Aetrix Electronics and suitable for switching mode power supplies, AC adapters, and LED lighting applications requiring stable component supply, consistent parametric performance, and long-term production support.

Supply support for SK59C 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 devices, and MOSFETs since 1979.

The SK52C–SK520C family was designed specifically for high-efficiency, surface-mount secondary-side rectification in cost-sensitive yet thermally demanding AC-DC and DC-DC converters across consumer and industrial markets.

FAQ

What is the maximum junction temperature rating for the SK59C?

The SK59C has a maximum junction temperature (T_J) rating of +150°C, with a storage temperature range of −55°C to +150°C. This allows operation in high-ambient environments such as enclosed LED drivers or industrial power modules. Thermal design must ensure that power dissipation - calculated using V_F × I_F and R_θJA - does not exceed this limit under worst-case load and ambient conditions. The SK59C datasheet specifies R_θJA = 53 °C/W on a 16 mm × 16 mm Cu pad.

Does the SK59C have a specified reverse recovery time (t_rr)?

No - the SK59C is a Schottky barrier rectifier and therefore has no minority-carrier reverse recovery time. Its operation relies on majority-carrier conduction, resulting in effectively zero t_rr. This eliminates switching losses associated with reverse recovery charge (Q_rr) and makes the SK59C ideal for high-frequency SMPS designs where conventional PN diodes would generate excessive noise and heat. The SK59C's dV/dt rating of 10,000 V/µs further confirms its suitability for fast-switching topologies.

What is the cathode marking convention for the SK59C in DO-214AB package?

The SK59C uses a molded cathode band on the body of the DO-214AB (SMC) package to indicate the cathode terminal. This band aligns with Pin 2 in the standard DO-214AB pinout - the lead opposite the tabbed edge when viewed with marking side up and cathode band to the left. Correct orientation is essential: reversing the SK59C in PCB layout will cause open-circuit failure or catastrophic reverse breakdown. The marking code "SK59C" appears adjacent to the band, and the device is polarity-sensitive.

Is the SK59C suitable for use in automotive applications?

The SK59C is not AEC-Q101 qualified and is not recommended for automotive safety-critical or under-hood applications per TSC's product notice. While its −55°C to +150°C operating range meets some automotive ambient requirements, TSC explicitly states these devices are "not designed for use in medical, life-saving, or life-sustaining applications" - a category that includes automotive ADAS and powertrain systems. For automotive-grade alternatives, consult TSC's AEC-Q101-certified Schottky rectifier portfolio or qualified equivalents such as SB590-AEC.

How does the SK59C's forward voltage compare across temperature?

The SK59C's forward voltage decreases with rising junction temperature - a characteristic of Schottky diodes. At 5 A, V_F is typically 0.85 V at 25°C, ~0.78 V at 100°C, and ~0.75 V at 125°C. This negative temperature coefficient improves thermal stability in parallel configurations and reduces conduction loss at elevated temperatures. However, reverse leakage current increases significantly: from 0.3 mA at 25°C to 5 mA at 125°C, requiring careful thermal management to avoid thermal runaway in high-density layouts.