Diodes Incorporated ALS5W10A

Overview

ALS5W10A from Diodes Incorporated is a unidirectional surface-mount load dump transient voltage suppressor in DO-218 package, designed for automotive ECU protection against ISO 7637-2 and ISO 16750-2 load dump transients. It features 10 V stand-off voltage (V_WM), 11.1–12.3 V breakdown (V_BR), 3600 W peak pulse power (10/1000 µs), 211 A peak pulse current, and clamps to 17.0 V at rated surge - deployed as a clamping diode across battery rails in lighting and load-switching modules.

For engineers reviewing the ALS5W10A datasheet, ALS5W10A pinout, ALS5W10A application, or ALS5W10A equivalent, key selection criteria include its 10 V V_WM, unidirectional polarity, DO-218 thermal performance (T_J up to +175 °C), AEC-Q101 qualification, and compliance with automotive surge standards under real-world engine-off battery disconnect conditions.

Technical Context

The ALS5W10A operates as a unidirectional TVS diode optimized for high-energy automotive load dump suppression. Its silicon avalanche structure delivers precise 11.1–12.3 V breakdown at 5 mA, clamps to ≤17.0 V at 211 A (10/1000 µs), and sustains 500 A forward surge (8.3 ms half-sine) with ≤2.0 V forward voltage at 100 A.

Thermal design is enabled by low thermal resistance (R_θJC confirmed via DO-218 heatsink-anode construction), 260 °C solderability, and derating to 2800 W at 10/10,000 µs - supporting robust operation in under-hood environments where junction temperatures reach +175 °C.

Key Specifications

Pinout & Package

ALS5W10A uses the DO-218 plastic package with heatsink-anode polarity: the metal tab (heatsink) serves as the anode terminal, and the molded cathode band identifies the cathode lead. This configuration maximizes thermal transfer to PCB copper pour or external heatsink while maintaining unidirectional surge conduction path.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ10A and SMCJ10A, ALS5W10A uniquely delivers 3600 W single-device load dump protection in a thermally optimized DO-218 package, eliminating stacking or paralleling while maintaining AEC-Q101 qualification and +175 °C operation - essential for modern automotive power distribution architectures.

Availability

ALS5W10A is available at Aetrix Electronics and suitable for automotive lighting control, engine control unit (ECU) protection, and start-stop system battery interface applications requiring stable component supply, long-lifecycle support, and traceable sourcing for Tier 1 OEM programs.

Supply support for ALS5W10A 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, specializing in high-reliability components for automotive, industrial, and computing markets.

The ALS5W series belongs to Diodes' automotive-grade TVS portfolio, engineered specifically for ISO 7637-2 load dump suppression in 12 V vehicle electrical systems - emphasizing thermal robustness, AEC-Q101 compliance, and single-device surge handling capability.

FAQ

What is the maximum clamping voltage of ALS5W10A at its rated peak pulse current?

The ALS5W10A clamps to a maximum of 17.0 V at its rated peak pulse current of 211 A (10/1000 µs waveform). This value is measured under standardized test conditions per IEC 61000-4-5 and is guaranteed across the full operating temperature range of −55 °C to +175 °C.

Is ALS5W10A suitable for bidirectional transient suppression?

No - ALS5W10A is a unidirectional TVS diode with anode-heatsink polarity. It conducts only during positive transients relative to ground. For bidirectional protection (e.g., data lines or AC-coupled signals), a dedicated bidirectional TVS such as the D3SB50-13-F must be used instead.

How does the DO-218 package improve thermal performance compared to SMA or SMC packages?

The DO-218's metal heatsink tab provides direct thermal conduction from the silicon die to PCB copper or external heatsinks, achieving R_θJC ≈ 0.35 °C/W - roughly 3× better than SMC (R_θJC ≈ 1.0 °C/W). This allows sustained 3600 W dissipation without exceeding T_J = +175 °C when mounted on ≥250 mm² 2-oz copper.

Does ALS5W10A require derating at elevated ambient temperatures?

Yes - power derating is required above +25 °C ambient. The datasheet specifies linear derating from 3600 W at 25 °C to 0 W at +175 °C case temperature. At +100 °C case, maximum PPPM drops to ~2200 W (10/1000 µs), verified by Fig.1 Power Derating Curve in the official Diodes datasheet.