Vishay General Semiconductor - Diodes Division SMAJ8.0AHE3_A/H

Overview

SMAJ8.0AHE3_A/H from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed to protect sensitive electronics against voltage transients induced by inductive load switching and lightning surges. It features a 8.0 V stand-off voltage (VWM), 8.89–9.83 V breakdown voltage (VBR) at 10 mA test current, and clamps up to 13.6 V at 29.4 A peak pulse current (IPPM) under 10/1000 μs waveform.

For engineers reviewing the SMAJ8.0AHE3_A/H datasheet, SMAJ8.0AHE3_A/H pinout, SMAJ8.0AHE3_A/H application, or SMAJ8.0AHE3_A/H equivalent, key selection criteria include its AEC-Q101 qualification for automotive use, 400 W peak pulse power rating (10/1000 μs), low clamping ratio (VC/VBR ≈ 1.45), and RoHS-compliant matte tin-plated leads suitable for automated SMT assembly.

Technical Context

This unidirectional TVS diode operates as a clamping device across power rails or signal lines, entering avalanche conduction when reverse voltage exceeds its breakdown threshold. Its glass-passivated junction ensures stable VBR tolerance and low leakage (<50 μA at VWM), while MSL Level 1 moisture sensitivity supports lead-free reflow without popcorn risk.

The device delivers 400 W peak pulse power (derated to 300 W above 78 V) with fast response time (<1.0 ps), low incremental surge resistance, and thermal resistance of 120 °C/W (junction-to-ambient) on standard 0.2" × 0.2" copper pads. Polarity is marked by cathode band; anode connects to PCB ground or low-impedance return path.

Key Specifications

Pinout & Package

Package: SMA (DO-214AC), surface-mount, single-axis polarity marking. Cathode indicated by band; anode is unmarked end. Leads are matte tin-plated, solderable per J-STD-002 and JESD 22-B102.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ8.0AHE3_A/H, the SMAJ8.0A-E3/61 offers identical protection performance at lower cost but lacks automotive qualification, while SMAJ8.0AHM3_A/H adds halogen-free compliance without sacrificing AEC-Q101 validation-enabling drop-in substitution where material restrictions apply.

Availability

SMAJ8.0AHE3_A/H is available at Aetrix Electronics and suitable for automotive ECUs, industrial sensor nodes, consumer USB power delivery systems, and telecom PHY protection requiring stable component supply and full AEC-Q101 traceability.

Supply support for SMAJ8.0AHE3_A/H 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 is a global leader in discrete semiconductors, specializing in diodes, rectifiers, MOSFETs, and protection devices with emphasis on reliability, efficiency, and automotive-grade qualification.

The SMAJ series targets board-level transient protection in harsh environments; engineered for high pulse power density, low clamping, and seamless integration into automotive, industrial, and communications power architectures.

FAQ

What is the maximum clamping voltage of SMAJ8.0AHE3_A/H at its rated peak pulse current?

The SMAJ8.0AHE3_A/H has a maximum clamping voltage (VC) of 13.6 V at its rated peak pulse current (IPPM) of 29.4 A under the standard 10/1000 μs waveform. This value is measured per IEC 61000-4-5 and ensures downstream components see limited overvoltage during surge events. The clamping performance is guaranteed across the full operating temperature range of −55 °C to +150 °C.

Is SMAJ8.0AHE3_A/H suitable for automotive applications?

Yes, SMAJ8.0AHE3_A/H is AEC-Q101 qualified and specifically designed for automotive use. Its qualification covers temperature cycling, highly accelerated life testing (HALT), and ESD robustness per JESD22-A114. The "HE3" suffix denotes RoHS-compliant and AEC-Q101-qualified construction, making SMAJ8.0AHE3_A/H appropriate for engine control modules, body electronics, and ADAS power supplies.

What is the reverse leakage current specification for SMAJ8.0AHE3_A/H at its stand-off voltage?

At its 8.0 V stand-off voltage (VWM), the SMAJ8.0AHE3_A/H exhibits a maximum reverse leakage current (ID) of 50 μA at 25 °C. This low leakage ensures minimal power loss in always-on circuits and avoids false triggering in high-impedance sensor interfaces. Leakage remains below 200 μA up to +125 °C, supporting reliable operation in under-hood environments.

Does SMAJ8.0AHE3_A/H have a defined polarity marking, and how is it identified?

Yes, SMAJ8.0AHE3_A/H is unidirectional and features a visible cathode band on the SMA (DO-214AC) package body. The banded end is the cathode and must be connected to the line being protected (e.g., 12 V rail), while the unbanded end is the anode and connects to ground. This polarity is consistent across all unidirectional SMAJ variants and is verified per JEDEC outline DO-214AC mechanical drawings.

What is the thermal resistance from junction to ambient for SMAJ8.0AHE3_A/H, and how does it affect layout?

The typical junction-to-ambient thermal resistance (RθJA) of SMAJ8.0AHE3_A/H is 120 °C/W when mounted on minimum recommended 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. To maintain safe operation at full 400 W pulse rating, PCB layout must provide adequate copper area and avoid thermal bottlenecks. For sustained power dissipation, thermal vias and internal ground planes are recommended to reduce effective RθJA below 80 °C/W.