Taiwan Semiconductor Corporation SK39B M4G

Overview

SK39B M4G from Taiwan Semiconductor is a 3A, 90V Schottky barrier surface-mount rectifier in DO-214AA (SMB) package, optimized for high-efficiency switching power supplies with low forward voltage (0.85 V at 3 A, 25°C) and high surge capability (70 A IFSM). It features guard ring overvoltage protection, J-STD-020 Level 1 moisture sensitivity, and RoHS/halogen-free compliance.

For engineers reviewing the SK39B M4G datasheet, SK39B M4G pinout, SK39B M4G application, or SK39B M4G equivalent, key selection criteria include its 90 V VRRM rating, 0.85 V VF at rated current, 100 µA IR at 25°C, 2 mA IR at 125°C, and thermal resistance (RθJL = 23°C/W), critical for thermal design in compact SMPS and DC-DC converters.

Technical Context

The SK39B M4G implements a single-die Schottky junction structure with a guard ring to enhance transient overvoltage robustness. Its low VF enables reduced conduction losses in high-frequency switching topologies, while the 70 A IFSM rating supports reliable operation during line surges and startup transients.

Thermally, it uses a DO-214AA (SMB) package with matte tin-plated leads and achieves RθJL = 23°C/W and RθJA = 63°C/W. Polarity is marked by a cathode band, and the device operates across –55°C to +150°C junction temperature range.

Key Specifications

Pinout & Package

Package: DO-214AA (SMB), surface-mount, single-anode/single-cathode configuration. Cathode indicated by molded 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 VS-3EYH09-M3/45 and SB390, the SK39B M4G offers tighter IR specification (100 µA), superior thermal resistance (RθJL = 23°C/W), and documented guard ring protection-making it preferred for high-reliability, thermally constrained, or transient-heavy industrial SMPS designs.

Availability

SK39B M4G is available at Aetrix Electronics and suitable for AC-DC adapters, USB-C PD power delivery systems, and industrial DC-DC converters requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for SK39B M4G 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 SK32B–SK320B family was designed specifically for high-efficiency, surface-mount switching power conversion-emphasizing low VF, robust surge handling, and JEDEC-compliant packaging for automated assembly.

FAQ

What is the maximum junction temperature rating for SK39B M4G?

The SK39B M4G has a maximum junction temperature (TJ max) of +150°C, verified per absolute maximum ratings in the official Taiwan Semiconductor datasheet (P2212). This rating applies under steady-state conditions with proper PCB thermal design and allows operation in elevated ambient environments typical of enclosed LED drivers or industrial power modules. The SK39B M4G must not exceed this limit to maintain reliability and parametric stability.

Does SK39B M4G have a guard ring, and what does it do?

Yes, the SK39B M4G incorporates a guard ring structure explicitly stated in its features list. This design element enhances edge termination robustness, improving immunity to voltage transients and preventing premature avalanche breakdown at the die periphery. As confirmed in the datasheet, it directly supports the device's 10,000 V/µs critical rate of rise of off-state voltage (dV/dt) rating, making SK39B M4G suitable for noisy switch-mode environments.

What is the forward voltage of SK39B M4G at 3 A and 125°C?

The forward voltage (VF) of SK39B M4G is not specified at 125°C in the provided datasheet; only VF at 25°C (max 0.85 V) and IR at 125°C (max 2 mA) are given. VF increases with temperature, so actual VF at 125°C will be higher than 0.85 V-designers should consult the Fig.10 Typical Forward Characteristics curve (SK39–310B group) in the SK32B–SK320B datasheet (P2212, page 5) to interpolate VF at elevated junction temperatures for the SK39B M4G.

Is SK39B M4G RoHS and halogen-free compliant?

Yes, SK39B M4G is RoHS compliant and halogen-free per IEC 61249-2-21, as confirmed in the "Features" section of the Taiwan Semiconductor SK32B–SK320B datasheet (P2212). The molding compound is UL 94V-0 rated, and terminals are matte tin plated-ensuring compatibility with lead-free reflow processes and environmental compliance requirements for consumer, industrial, and lighting end equipment using SK39B M4G.

What is the moisture sensitivity level (MSL) of SK39B M4G?

The SK39B M4G has a moisture sensitivity level (MSL) of Level 1 per J-STD-020, meaning it is not humidity-sensitive and can be stored indefinitely at ambient conditions without dry-packaging or baking prior to reflow. This MSL rating is explicitly listed in the "Features" section of the official Taiwan Semiconductor datasheet (P2212) and simplifies handling and assembly for high-volume SMT lines using SK39B M4G.