Taiwan Semiconductor Corporation S2BA

Overview

S2BA from Diodes Incorporated is a glass passivated surface-mount silicon rectifier diode in SMA package, rated for 100 V peak repetitive reverse voltage (VRRM), 1.5 A average forward current (I(AV)) at 100°C terminal temperature, and 50 A non-repetitive surge current (IFSM); used as primary AC/DC input rectifier in low-power offline power supplies.

For engineers reviewing the S2BA datasheet, S2BA pinout, S2BA application, or S2BA equivalent, key selection criteria include its 1.15 V forward voltage at 1.5 A, 5 µA max reverse leakage at 25°C, 20 pF junction capacitance, thermal resistance of 20 °C/W, and compatibility with automated SMT assembly on FR-4 PCBs with minimal copper pad area.

Technical Context

This device operates as a single-phase, half-wave rectifier under 60 Hz AC line conditions with resistive or inductive loads; capacitive loads require 20% derating of I(AV). Its glass passivated die construction ensures stable reverse characteristics across -65°C to +150°C operating range.

The SMA package provides defined thermal path to PCB copper pads (5.0 mm², 0.013 mm thick), enabling reliable power dissipation up to 1.5 A with junction-to-terminal thermal resistance of 20 °C/W - critical for compact, convection-cooled adapters and auxiliary power rails.

Key Specifications

Pinout & Package

SMA package: molded plastic case, UL 94V-0 rated, cathode indicated by band or notch, polarity-critical for correct rectifier orientation. Dimensions: A = 2.29–2.92 mm, B = 4.00–4.60 mm, C = 1.27–1.63 mm, E = 4.80–5.59 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MBR1100, S2BA trades higher VFM for lower leakage and wider temperature range; compared with S2B, it sacrifices thermal resistance for smaller PCB area - making it optimal for miniaturized, thermally stable, and leakage-sensitive 1.5 A rectifier roles.

Availability

S2BA is available at Aetrix Electronics and suitable for AC-DC wall adapters, industrial control power supplies, and appliance standby power circuits requiring stable component supply and RoHS-compliant manufacturing.

Supply support for S2BA 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the US.

The S2x/A series targets cost-sensitive, high-volume power conversion applications where reliability, thermal robustness, and automated assembly compatibility are prioritized over ultra-low forward voltage.

FAQ

What is the maximum allowable PCB copper pad area for thermal performance validation?

The datasheet specifies thermal resistance RJT = 20 °C/W is measured with 5.0 mm² of 0.013 mm thick copper pad per terminal. Using less copper increases thermal resistance linearly; doubling pad area yields ~15 °C/W. No minimum pad size is defined, but <2.5 mm² risks exceeding 150°C junction temperature at full 1.5 A load.

Can S2BA be used in full-wave bridge configurations?

Yes - S2BA is a single diode and may be used as one quadrant in a discrete full-wave bridge. Four S2BA devices can form a 100 V, 1.5 A bridge. However, integrated bridges (e.g., GBU4K) offer tighter matching, smaller footprint, and pre-characterized thermal coupling - preferred unless discrete layout or voltage derating flexibility is required.

Is the "A" suffix in S2BA strictly tied to SMA packaging?

Yes. Per Diodes Incorporated's ordering nomenclature, the "A" suffix denotes SMA package (e.g., S2BA = SMA, S2B = SMB). This is confirmed in the mechanical data section and marking diagram: "A Suffix Designates SMA Package. No Suffix Designates SMB Package." No exceptions or alternate interpretations exist in the official documentation.

How does capacitive load derating affect practical design margins?

Capacitive load derating (20% I(AV) reduction) applies when rectifying into large bulk capacitors without series impedance. For S2BA, this lowers usable current to 1.2 A. Designers must verify ripple current rating of downstream capacitors and ensure transformer VA rating supports peak charging currents - which can exceed 5× average load current in worst-case scenarios.