Taiwan Semiconductor Corporation SRAS2040

Overview

SRAS2040 from Taiwan Semiconductor is a 20A, 40V repetitive peak reverse voltage Schottky barrier rectifier in TO-263AB (D2PAK) package, optimized for high-efficiency switching mode power supplies, DC-DC converters, and AC adapters. It delivers low forward voltage (0.57 V at 20 A, 25°C), high surge current capability (330 A), and junction-to-case thermal resistance of 1.5 °C/W.

For engineers reviewing the SRAS2040 datasheet, SRAS2040 pinout, SRAS2040 application, or SRAS2040 equivalent, key selection criteria include its 40 V V_RRM, 20 A continuous forward current rating, 330 A I_FSM, thermal performance in high-power density designs, and RoHS/halogen-free compliance for industrial and consumer power systems.

Technical Context

The SRAS2040 employs a single-die Schottky barrier structure with guard ring overvoltage protection, enabling robust operation under transient stress. Its low VF minimizes conduction loss in high-frequency switching topologies, while the TO-263AB package supports high-current PCB routing and efficient heat dissipation via the exposed cathode tab.

Rated for TJ = –55°C to +150°C and moisture sensitivity level 1 (J-STD-020), the device is qualified for reflow soldering and automated placement. Reverse leakage remains ≤500 µA at 25°C and ≤15 mA at 100°C under rated VR, supporting stable performance across operating temperature ranges.

Key Specifications

Pinout & Package

Package: TO-263AB (D2PAK) - surface-mount power package with exposed cathode tab for thermal and electrical connection; 3-terminal configuration (Anode, Cathode, Cathode Tab).

Key Features

Applications

Equivalent & Alternatives

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

Compared with VS-20BQ040-M3/45 and SB2040, the SRAS2040 offers the lowest forward voltage (0.57 V) and best thermal resistance (1.5 °C/W), making it optimal for space-constrained, high-efficiency 40 V rectification where thermal headroom is limited.

Availability

SRAS2040 is available at Aetrix Electronics and suitable for switching mode power supplies, AC adapters, and DC-DC converters requiring stable component supply, long-term lifecycle support, and RoHS-compliant Schottky rectification.

Supply support for SRAS2040 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 power discrete manufacturer headquartered in Hsinchu, Taiwan, serving global industrial, computing, and consumer markets since 1979.

The SRAS2040 belongs to TSC's high-current Schottky rectifier product line, engineered specifically for efficiency-critical secondary-side rectification in compact, high-frequency power conversion systems.

FAQ

What is the maximum junction temperature rating for the SRAS2040?

The SRAS2040 has a maximum junction temperature (T_J) rating of +150°C, verified per absolute maximum ratings in the official datasheet. This allows reliable operation in thermally demanding environments such as enclosed power adapters or high-density DC-DC modules. Derating curves confirm usable current capacity down to 10 A at 125°C case temperature. The SRAS2040 must be mounted with adequate copper area on the cathode tab to maintain T_J within limits under full 20 A load.

Does the SRAS2040 have a guard ring structure, and what benefit does it provide?

Yes, the SRAS2040 incorporates a guard ring for overvoltage protection, explicitly stated in its features list. This structure enhances edge termination robustness, suppressing premature avalanche breakdown during fast transient voltage spikes-common in flyback transformer reset or inductive load switching. In practice, this improves reliability in SMPS designs subject to line surges or layout-induced ringing. The SRAS2040's guard ring directly contributes to its ability to sustain rated V_RRM under real-world dv/dt stress.

What is the forward voltage of the SRAS2040 at 20 A and 100°C junction temperature?

The SRAS2040 forward voltage increases with temperature: at 20 A and 100°C junction temperature, V_F rises to approximately 0.52 V (typical), based on the device's negative temperature coefficient and curve extrapolation from the published 25°C and 125°C data points. This value is confirmed by Figure 4 (Typical Forward Characteristics) in the SRAS2020–SRAS20150 datasheet. Designers should use this elevated V_F for worst-case thermal loss calculations in the SRAS2040.

Is the SRAS2040 halogen-free and RoHS compliant?

Yes, the SRAS2040 is both RoHS compliant and halogen-free per IEC 61249-2-21, as documented in the "Features" section of the official datasheet. The molding compound contains no brominated or chlorinated flame retardants, and lead content is below 1000 ppm. These certifications are verified through TSC's material declarations and third-party testing reports. The SRAS2040 meets environmental compliance requirements for CE-marked industrial and consumer power products.

What packaging format is used for the SRAS2040, and how many units are per reel?

The SRAS2040 is supplied in TO-263AB (D2PAK) package on tape-and-reel, with 800 units per reel, as specified in the "Ordering Information" section of the datasheet. The tape conforms to EIA-481 standards and supports automated pick-and-place assembly. Reel dimensions and orientation follow standard D2PAK carrier tape specifications, ensuring compatibility with high-speed SMT lines. Aetrix Electronics stocks SRAS2040 in full reels and offers cut-tape options for prototyping and low-volume builds.