Vishay General Semiconductor - Diodes Division SMA6J26A-E3/5A

Overview

SMA6J26A-E3/5A from Vishay General Semiconductor is a unidirectional surface-mount TransZORB® transient voltage suppressor in SMA (DO-214AC) package, with 26 V stand-off voltage (VWM), 28.9–31.9 V breakdown voltage (VBR at IT = 1 mA), 40.9 V maximum clamping voltage at 14.7 A (10/1000 μs), 600 W peak pulse power rating, and 150 °C max junction temperature - used to protect MOSFETs and ICs against inductive switching transients in industrial power supplies.

For engineers reviewing the SMA6J26A-E3/5A datasheet, SMA6J26A-E3/5A pinout, SMA6J26A-E3/5A application, or SMA6J26A-E3/5A equivalent, key selection criteria include clamping voltage margin vs. protected device VDS/VDD, unidirectional polarity compatibility with DC-biased lines, 600 W 10/1000 μs surge capability, thermal resistance (RθJA = 120 °C/W), and RoHS-compliant matte tin-plated leads for J-STD-002 solderability.

Technical Context

This device operates as a silicon avalanche diode optimized for fast-response transient suppression on DC power rails and signal lines. Its unidirectional structure provides low-leakage reverse blocking up to 26 V (VWM) and sharp avalanche turn-on above 28.9 V (min VBR), enabling precise overvoltage threshold control without forward conduction during normal operation.

Clamping performance is defined by dynamic resistance (RD = 0.614 Ω) and follows VCL = RD × IPP + VBRmax, yielding 40.9 V at 14.7 A (10/1000 μs) and 47.9 V at 75 A (8/20 μs). Thermal design relies on PCB copper pad layout (5.0 mm × 5.0 mm per terminal) to manage 4 W power dissipation at TA = 50 °C and sustain IFSM = 50 A surge current.

Key Specifications

Pinout & Package

Package: SMA (DO-214AC), surface-mount, low-profile plastic case meeting UL 94 V-0; cathode indicated by molded band; matte tin-plated leads compliant with J-STD-002 and JESD 22-B102.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient voltage suppression applications.

Compared with SMA6J26A-E3/5A, SMA6J26CA-E3/5A adds bidirectional symmetry at the cost of DC rail compatibility, while SMCJ26A-E3/57T trades compactness for 2.5× higher surge power and better thermal management - both require explicit validation for polarity, layout, and clamping margin in target circuits.

Availability

SMA6J26A-E3/5A is available at Aetrix Electronics and suitable for industrial motor drives, DC power rail clamping, and automotive body control modules requiring stable component supply with RoHS-compliant, tape-and-reel packaging (7500 pcs per 13″ reel).

Supply support for SMA6J26A-E3/5A 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

Vishay General Semiconductor designs and manufactures discrete semiconductors including diodes, rectifiers, and TVS devices, with emphasis on reliability, surge robustness, and AEC-Q200 qualification for industrial and automotive markets.

The SMA6JxxA series targets cost-sensitive, high-volume transient protection in space-constrained applications, leveraging Vishay's TransZORB® avalanche technology to deliver precise clamping and long-term stability under repetitive surge stress.

FAQ

What is the maximum clamping voltage of the SMA6J26A-E3/5A at 14.7 A?

The SMA6J26A-E3/5A has a maximum clamping voltage (VC) of 40.9 V at 14.7 A using the 10/1000 μs waveform. This value is measured under standardized test conditions with specified PCB mounting (5.0 mm × 5.0 mm copper pads per terminal) and reflects the peak voltage imposed on protected circuitry during a typical inductive transient event. The SMA6J26A-E3/5A maintains this clamping performance across its rated temperature range.

Is the SMA6J26A-E3/5A suitable for protecting bidirectional signal lines like RS-485?

No, the SMA6J26A-E3/5A is unidirectional and designed only for DC-biased applications such as power rails or single-ended sensor outputs. For RS-485 or other bidirectional interfaces, a bidirectional variant like SMA6J26CA-E3/5A is required. Using SMA6J26A-E3/5A on AC-coupled lines risks forward conduction and failure during negative transients - always verify polarity alignment before deploying SMA6J26A-E3/5A.

What is the thermal resistance and how does it affect PCB layout for the SMA6J26A-E3/5A?

The SMA6J26A-E3/5A has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W, which assumes mounting on 5.0 mm × 5.0 mm copper pads per terminal. To achieve rated 4 W power dissipation at TA = 50 °C, the PCB must provide adequate copper area and thermal vias; reducing pad size increases junction temperature and de-rates surge capability. The SMA6J26A-E3/5A datasheet specifies this pad layout as minimum for compliance with derating curves.

Does the SMA6J26A-E3/5A meet RoHS and lead-free soldering requirements?

Yes, the "E3" suffix denotes RoHS-compliant construction with matte tin-plated leads qualified for lead-free reflow per J-STD-020 MSL Level 1 (peak 260 °C). The SMA6J26A-E3/5A passes JESD 201 Class 2 whisker testing and uses UL 94 V-0 molding compound. It is certified for industrial-grade reliability and supports Pb-free assembly without special handling or pre-baking.

How does the leakage current of the SMA6J26A-E3/5A impact low-power applications?

The SMA6J26A-E3/5A exhibits ≤0.2 μA maximum reverse leakage current (ID) at its 26 V stand-off voltage (VWM), making it suitable for battery-powered or energy-harvesting systems where standby current must be minimized. This ultra-low leakage avoids measurable drain on 26 V supply rails and ensures stable operation in high-impedance sensor front-ends - a key advantage over higher-leakage TVS alternatives that compromise system quiescent power budgets.