Taiwan Semiconductor Corporation S2KFS

Overview

S2KFS from Taiwan Semiconductor is a 2 A, 800 V standard surface-mount silicon rectifier diode in SOD-128 package, featuring glass-passivated junction, 50 A surge rating (8.3 ms), and 1.10 V max forward voltage at 2 A/25°C. It serves as primary AC/DC input rectification in compact off-line power supplies.

For engineers reviewing the S2KFS datasheet, S2KFS pinout, S2KFS application, or S2KFS equivalent, key selection criteria include peak reverse voltage (800 V), thermal resistance (R_θJL = 14 °C/W), moisture sensitivity level (MSL 1), RoHS/halogen-free compliance, and SOD-128 footprint compatibility with automated placement.

Technical Context

The S2KFS operates as a single-die, unidirectional standard recovery rectifier optimized for switching-mode power conversion up to 100 kHz. Its glass-passivated junction ensures stable reverse leakage (<1 µA @ 25°C, <33 µA @ 125°C) and robust surge tolerance (140 A @ 1.0 ms).

Thermal performance is defined for PCB mounting on 5 mm × 5 mm copper pads: R_θJA = 74 °C/W, R_θJC = 20 °C/W, enabling reliable operation at T_J up to +150°C under continuous 2 A DC load with appropriate board layout.

Key Specifications

Pinout & Package

Package: SOD-128 - Surface-mount, molded plastic case with matte tin-plated leads, UL 94V-0 rated, polarity indicated by cathode band, weight ≈ 0.027 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STTH2R08 and ES2J, the S2KFS uniquely balances 800 V rating, SOD-128 compactness, and low 1.10 V V_F, making it optimal for space-constrained, universal-input SMPS where thermal path efficiency and regulatory compliance are critical.

Availability

S2KFS is available at Aetrix Electronics and suitable for AC/DC adapters, industrial switch-mode power supplies, and LED drivers requiring stable component supply with full traceability and lifecycle management.

Supply support for S2KFS 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 industrial, computing, and consumer markets since 1979.

The S2KFS belongs to TSC's S2xFS family of standard rectifiers designed specifically for high-reliability, high-volume surface-mount power conversion applications demanding MSL 1, halogen-free construction, and consistent parametric performance across voltage grades.

FAQ

What is the maximum junction temperature rating for the S2KFS?

The S2KFS has a maximum junction temperature (T_J) rating of +150°C, verified per absolute maximum ratings table in the official Taiwan Semiconductor datasheet (Version B2103). This rating applies under continuous forward conduction and defines the upper thermal limit for reliable long-term operation. Derating curves in the datasheet specify allowable I_F reduction above 75°C ambient. The S2KFS must be mounted on a PCB with adequate copper area to maintain T_J ≤ 150°C under actual load conditions.

Does the S2KFS have a specified moisture sensitivity level (MSL)?

Yes, the S2KFS is rated MSL Level 1 per J-STD-020, confirmed in the "Features" section of the Taiwan Semiconductor datasheet (Version B2103). This means the device has unlimited floor life at ≤30°C/60% RH and requires no dry-packaging or baking prior to reflow soldering. The S2KFS is fully compatible with standard lead-free reflow profiles without moisture-induced popcorning risk.

What is the forward voltage of the S2KFS at 2 A and 125°C?

The forward voltage of the S2KFS is 0.88 V (typical) and 0.98 V (maximum) at I_F = 2 A and T_J = 125°C, as specified in the Electrical Specifications table (Version B2103). This lower V_F at elevated temperature improves thermal stability in high-ambient applications compared to room-temperature values, and directly reduces conduction losses in warm-running power stages.

Is the S2KFS RoHS and halogen-free compliant?

Yes, the S2KFS is RoHS compliant and halogen-free per IEC 61249-2-21, as explicitly stated in the "Features" section of the Taiwan Semiconductor datasheet (Version B2103). Compliance is verified through material declarations and testing; the device contains no brominated flame retardants (BFRs), antimony trioxide, or other restricted halogen compounds, meeting global environmental regulations for industrial and consumer electronics.

What is the marking code printed on the S2KFS device body?

The marking code printed on the S2KFS device body is "S2KFS", as shown in the "Marking Diagram" and "Ordering Information" sections of the Taiwan Semiconductor datasheet (Version B2103). This laser-marked identifier appears adjacent to the cathode band and is used for visual part verification and traceability during assembly and inspection. No additional date or factory codes are required for basic identification of the S2KFS.