Taiwan Semiconductor Corporation SK54B

Overview

SK54B from Taiwan Semiconductor is a 40V, 5A surface-mount Schottky barrier rectifier in DO-214AA (SMB) package, featuring low forward voltage drop (0.55V at 5A), fast recovery time (<5ns), and operating junction temperature up to 150°C. It serves as output rectifier in AC/DC and DC/DC power supplies for telecom and industrial converters.

For engineers reviewing the SK54B datasheet, SK54B pinout, SK54B application, or SK54B equivalent, key selection criteria include forward voltage at rated current, thermal resistance (R_θJA = 50°C/W), peak repetitive reverse voltage (V_RRM = 40V), and surge current capability (I_FSM = 150A).

Technical Context

The SK54B belongs to Taiwan Semiconductor's SK52B–SK515B Schottky rectifier family, differentiated by V_RRM ratings (20V to 150V) and I_F(AV) (5A across all variants). All share identical DO-214AA package, cathode-banded anode-cathode polarity, and low-leakage design optimized for high-frequency switching.

Its performance is characterized under pulsed conditions (300μs, 1% duty cycle) and validated across -55°C to +150°C junction temperature range. Forward voltage exhibits minimal temperature dependence, while reverse leakage increases predictably with temperature-critical for thermal design in compact power stages.

Key Specifications

Pinout & Package

SK54B uses the DO-214AA (SMB) molded plastic package per JEDEC standard, with cathode indicated by a band on the body. The device has two terminals: anode and cathode, mounted on a single-sided PCB pad layout optimized for thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SS54 and SB540, SK54B delivers optimal balance of low V_F, superior thermal rating (150°C), and proven surge robustness-making it preferred for industrial and automotive power stages where reliability under thermal stress is critical.

Availability

SK54B is available at Aetrix Electronics and suitable for AC/DC adapters, DC/DC converters, LED drivers, and automotive body control modules requiring stable component supply and long-term industrial availability.

Supply support for SK54B 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 Taiwanese semiconductor manufacturer specializing in discrete power devices, including rectifiers, TVS diodes, and MOSFETs, with ISO/TS 16949 and AEC-Q101 qualified lines.

The SK52B–SK515B series was designed specifically for high-efficiency, high-reliability power conversion in industrial and telecom infrastructure-emphasizing thermal resilience, surge immunity, and consistent parametric performance across temperature extremes.

FAQ

What is the maximum junction temperature rating for SK54B?

The SK54B has a maximum junction temperature (T_J) rating of 150°C, verified per datasheet test conditions across the full operating range. This allows SK54B to maintain stable forward voltage and leakage characteristics in high-ambient environments such as enclosed power supplies or automotive under-hood applications where board temperatures exceed 100°C. Thermal design must ensure T_J does not exceed this limit under worst-case load and ambient conditions.

Does SK54B have a cathode marking, and how is polarity identified?

Yes, SK54B features a cathode band printed on the molded plastic body per JEDEC DO-214AA standard. The banded end is the cathode terminal; the opposite end is the anode. This marking is visible on the top surface and aligns with the "CATHODE INDICATOR" note in the official package drawing. Correct orientation is essential to prevent reverse conduction failure in DC/DC output stages.

What is the forward voltage of SK54B at 3A and 25°C?

Per the SK54B datasheet's typical forward voltage curve at T_J = 25°C, the forward voltage is approximately 0.49 V at 3A. This value is derived from the V_F vs. I_F plot for the SK52–SK54B subgroup and confirmed under 1% duty-cycle pulsed conditions. At higher currents or elevated temperatures, V_F increases slightly but remains below 0.55 V up to 5A.

Is SK54B suitable for use in synchronous rectification circuits?

SK54B is a standard Schottky rectifier-not a synchronous rectifier controller or MOSFET-and thus functions as a passive rectifying element. However, its sub-5ns reverse recovery time and low V_F make SK54B well-suited as a freewheeling or output rectifier in synchronous topologies where it replaces slower diodes. It does not integrate gate drive or control logic; external MOSFETs and controllers remain required for true synchronous operation.

What is the peak non-repetitive surge current rating for SK54B?

The SK54B is rated for a peak non-repetitive forward surge current (I_FSM) of 150A, tested using an 8.3ms single half-sine wave waveform. This rating reflects robustness against short-duration overloads such as inrush current during power-up or fault transients in motor drive or PoE applications. Repeated surges exceeding this limit or violating the specified pulse width/duty cycle may cause permanent degradation.