Taiwan Semiconductor Corporation S1DFS MWG

Overview

S1DFS from Taiwan Semiconductor is a 1 A, 200 V standard surface-mount silicon rectifier diode in SOD-128 package, featuring glass-passivated junction, 30 A surge rating, and 150 °C max junction temperature - used in DC-DC converters and switching-mode power supplies.

For engineers reviewing the S1DFS datasheet, S1DFS pinout, S1DFS application, or S1DFS equivalent, key selection factors include repetitive peak reverse voltage (200 V), forward voltage at 1 A (≤1.1 V @ 25 °C), thermal resistance (R_θJL = 29 °C/W), moisture sensitivity level (MSL 1), and RoHS/halogen-free compliance.

Technical Context

The S1DFS is a single-die, unidirectional silicon rectifier optimized for high-reliability surface-mount operation. Its glass-passivated junction ensures stable reverse leakage (<1 µA @ 25 °C, <50 µA @ 125 °C) and robust surge tolerance (30 A I_FSM, 8.3 ms half-sine).

Thermal performance is defined with PCB mounting on 5 mm × 5 mm copper pads: R_θJA = 82 °C/W, R_θJC = 30 °C/W, enabling continuous 1 A conduction up to 125 °C ambient when properly heatsinked.

Key Specifications

Pinout & Package

Package: SOD-128 - surface-mount, flat-lead, single-diode outline with cathode band marking; 5 mm × 3.7 mm footprint, 1.1 mm height; UL 94V-0 molding compound; matte tin-plated leads compliant with J-STD-002 solderability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MUR120 and VS-1EWH02-M3/5AT, the S1DFS delivers balanced performance for general-purpose 200 V rectification with industry-standard thermal and reliability specs - offering lowest cost per unit while maintaining MSL 1 handling and halogen-free compliance.

Availability

S1DFS is available at Aetrix Electronics and suitable for DC-DC converter output rectification, switching mode inverter freewheeling, and AC-DC auxiliary supply rectification requiring stable component supply, full traceability, and long-term lifecycle support.

Supply support for S1DFS 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 industrial, computing, and consumer markets since 1979.

The S1DFS belongs to TSC's S1xFS standard rectifier family, designed specifically for cost-effective, high-yield SMT deployment in low-to-medium power AC/DC and DC/DC conversion stages.

FAQ

What is the maximum junction temperature rating for the S1DFS?

The S1DFS has a maximum junction temperature (T_J) rating of +150 °C, as specified in its absolute maximum ratings table. This allows reliable operation in thermally demanding environments such as enclosed power supplies or proximity to heat-generating ICs. Derating curves in the datasheet confirm usable current capacity down to 125 °C ambient when mounted on standard PCB copper pads. The S1DFS must not exceed this limit to ensure long-term reliability and parametric stability.

Does the S1DFS have a defined surge current rating, and under what conditions?

Yes, the S1DFS is rated for a non-repetitive peak forward surge current (I_FSM) of 30 A, tested under an 8.3 ms single half-sine wave condition superimposed on rated load. This rating reflects its ability to survive short-duration inrush events like capacitor charging or motor startup transients. The surge capability is validated at T_A = 25 °C and assumes proper PCB thermal design - exceeding this value risks irreversible junction damage. The S1DFS datasheet does not specify repetitive surge endurance.

Is the S1DFS RoHS and halogen-free compliant, and which standards apply?

Yes, the S1DFS is RoHS compliant per EU Directive 2011/65/EU and halogen-free per IEC 61249-2-21. These certifications are explicitly stated in the product's features section and confirmed in the mechanical data table. Compliance is verified through material declarations and third-party testing of the molding compound and lead finish. No exemptions are claimed. This makes the S1DFS suitable for export-controlled and environmentally regulated applications including industrial automation and medical peripherals.

What is the moisture sensitivity level (MSL) of the S1DFS, and how does it affect assembly?

The S1DFS carries a moisture sensitivity level (MSL) rating of Level 1 per J-STD-020, meaning it has unlimited floor life at ≤30 °C/60% RH and requires no baking prior to reflow soldering. This eliminates pre-bake steps, reduces handling risk, and supports just-in-time SMT line integration. The MSL Level 1 status is enabled by the hermetic glass passivation and robust SOD-128 encapsulation - a key advantage over higher-MSL discrete diodes that demand strict dry-pack control and time-bound placement.

How does the forward voltage of the S1DFS vary with temperature and current?

The S1DFS forward voltage decreases with rising junction temperature: at 1 A, V_F is ≤1.1 V @ 25 °C but drops to ≤0.95 V @ 125 °C. This negative temperature coefficient helps balance current sharing in parallel configurations. At fixed temperature, V_F increases linearly with current - e.g., 0.99 V typ @ 1 A, 25 °C versus 0.91 V typ @ 0.5 A, 25 °C. These values are measured under pulsed conditions (PW = 0.3 ms) to avoid self-heating artifacts. The S1DFS datasheet provides full V_F vs. I_F curves across temperature.