Diodes Incorporated ALS6W28A

Overview

ALS6W28A from Diodes Incorporated is a unidirectional surface-mount load dump transient voltage suppressor (TVS) in DO-218 package, designed for automotive ECU protection against ISO 7637-2 and ISO 16750-2 load dump transients. It features 28.0 V stand-off voltage (V_WM), 31.1–34.4 V breakdown voltage (V_BR), 45.4 V clamping voltage at 101 A peak pulse current, and 4600 W peak pulse power (10/1000 µs).

For engineers reviewing the ALS6W28A datasheet, ALS6W28A pinout, ALS6W28A application, or ALS6W28A equivalent, key selection criteria include its 101 A I_PPM rating at 45.4 V clamping, AEC-Q101 qualification, -55 °C to +175 °C operating junction temperature, DO-218 mechanical outline, and compliance with automotive surge standards under defined test conditions.

Technical Context

The ALS6W28A operates as a unidirectional clamping diode with anode-connected heatsink polarity, optimized for high-energy transient suppression in 12 V automotive systems. Its low thermal resistance and high forward surge capability (600 A I_FSM) enable robust handling of 10 ms exponential load dump waveforms up to 4600 W at 25 °C case temperature.

It delivers stable clamping performance across temperature: maximum reverse leakage remains ≤150 µA at V_WM and ≤250 µA at 175 °C junction temperature, while forward voltage is capped at 1.9 V @ 100 A (8.3 ms half-sine). Power derating follows a defined curve down to zero watt at 200 °C case temperature.

Key Specifications

Pinout & Package

ALS6W28A uses the DO-218 plastic package with integrated heatsink. The anode is electrically connected to the metal heatsink tab, and the cathode is marked by a bar on the molded body. Leads are matte tin-plated for solderability per MIL-STD-750 Method 2026 and J-STD-002.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar unidirectional automotive load dump protection applications.

Compared with SMAJ28A and SMCJ28A, ALS6W28A provides 3× higher surge power margin in the same DO-218 footprint, eliminates need for paralleling, and guarantees single-device ISO 7637-2 Pulse 5a compliance - reducing BOM count and layout complexity in safety-critical ECUs.

Availability

ALS6W28A is available at Aetrix Electronics and suitable for automotive engine control units, body control modules, ADAS camera power supplies, and infotainment head units requiring stable component supply across extended temperature and high-reliability production cycles.

Supply support for ALS6W28A 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 with broad AEC-Q101 and PPAP capabilities.

ALS6W28A belongs to the ALS6WxxA series of high-power unidirectional TVS diodes engineered specifically for automotive load dump protection - balancing clamping precision, thermal robustness, and regulatory compliance in under-hood environments.

FAQ

What is the maximum clamping voltage of ALS6W28A under standard test conditions?

The maximum clamping voltage (V_C) is 45.4 V at 101 A peak pulse current using the 10/1000 µs waveform. This value is measured at T_A = 25 °C with specified mounting conditions (heatsink soldered to ≥250 mm² copper), and represents the upper limit of voltage seen by downstream circuitry during worst-case surge events.

Is ALS6W28A suitable for 24 V commercial vehicle applications?

No - ALS6W28A is rated for 28.0 V stand-off and optimized for 12 V automotive systems. For 24 V applications, Diodes offers ALS6W43A (V_WM = 43.0 V) which provides 69.4 V clamping and 4600 W pulse power compatible with ISO 7637-2 Pulse 5a in 24 V architectures.

How does the DO-218 package improve thermal performance over SMA or SMB packages?

The DO-218 package integrates a large metal heatsink tab directly bonded to the anode, enabling junction-to-board thermal resistance as low as 1.5 °C/W. This allows sustained 4600 W pulse dissipation without external heatsinks - unlike SMA/SMB packages that rely solely on lead-frame conduction and typically max out at ~1500 W.

Does ALS6W28A require derating at elevated ambient temperatures?

Yes - power derating is mandatory above 25 °C case temperature. The datasheet specifies linear derating from 4600 W at 25 °C to 0 W at 200 °C. At 125 °C case temperature, maximum allowable PPPM drops to ~2300 W; design margins must account for this using the published derating curve (Figure 1).