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Diodes Incorporated ALS6W40A
- Part No.:
- ALS6W40A
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
ALS6W40A.pdf
- Description:
- Transient Voltage Suppressor PP
- Quantity:
- Payment:
- Shipping:
Inventory:3,585
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Product details
Overview
ALS6W40A from Diodes Incorporated is a unidirectional surface-mount load dump transient voltage suppressor in DO-218 package, rated for 40 V standoff voltage (VWM), 44.4–49.1 V breakdown (VBR), 64.5 V clamping at 71 A peak pulse current, and 4600 W peak pulse power (10/1000 µs). It serves as a clamping diode for automotive ECU load dump protection, meeting ISO7637-2 and ISO16750-2 surge standards.
For engineers reviewing the ALS6W40A datasheet, ALS6W40A pinout, ALS6W40A application, or ALS6W40A equivalent, key selection criteria include its 40 V VWM, 64.5 V VC at 71 A, DO-218 thermal performance (TJ up to +175 °C), AEC-Q101 qualification, and unidirectional polarity with heatsink-anode configuration.
Technical Context
The ALS6W40A operates as a unidirectional TVS diode optimized for high-energy automotive load dump transients. Its silicon junction is engineered for low thermal resistance and stable clamping under 10 ms exponential waveforms, with guaranteed 260 °C soldering tolerance and MSL Level 1 rating.
It delivers 4600 W peak pulse power at 10/1000 µs and retains 3600 W at 10/10,000 µs, supporting robust protection in 12 V and 24 V automotive systems. The device exhibits ≤1.9 V forward voltage at 100 A surge and <10 µA reverse leakage at VWM and 25 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - Maximum continuous reverse operating voltage before clamping begins |
| VBR (min/max) | 44.4 V / 49.1 V - Breakdown occurs within this range at 5 mA test current |
| VC @ IPPM | 64.5 V - Clamping voltage at 71 A peak pulse current (10/1000 µs) |
| PPPM (10/1000 µs) | 4600 W - Peak surge power handling capability for standard load dump waveform |
| IFSM | 600 A - Non-repetitive forward surge current (8.3 ms half-sine) |
| TJ Range | −55 °C to +175 °C - Validated junction temperature range for automotive under-hood operation |
| AEC-Q101 | Qualified - Certified for automotive electronic component reliability per stress test standard |
Pinout & Package
Package: DO-218 plastic outline, anode-connected heatsink tab, matte tin-plated terminals, 2.74 g mass, UL94-V0 molding compound, 750 pcs/reel.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Heatsink Tab) | Current entry point during clamping | Electrically connected to case; must be mounted to PCB copper pour for thermal dissipation and low-inductance grounding |
| Cathode (Bar-marked Lead) | Current exit point during clamping | Marked with cathode band; connects to protected line (e.g., battery rail); defines unidirectional conduction direction |
Key Features
| Feature | Design Value |
|---|---|
| High-temperature stability | Operates reliably up to +175 °C junction temperature with <10 µA leakage at VWM |
| Low thermal resistance | DO-218 heatsink tab enables direct thermal path to PCB copper, critical for 4600 W pulse dissipation |
| Automotive surge compliance | Fully meets ISO7637-2 (Load Dump Pulse 5a) and ISO16750-2 test requirements across temperature |
| Lead-free & green construction | RoHS 3 compliant, halogen- and antimony-free (<900 ppm Br/Cl, <1000 ppm Sb), J-STD-020 MSL Level 1 |
| High surge robustness | Withstands 600 A single half-sine surge (8.3 ms) and maintains clamping integrity after repeated 10/1000 µs pulses |
Applications
| Engine Control Unit Protection | LED Headlamp Driver Protection |
|---|---|
Use Scenario: Protects microcontroller power rails and CAN transceivers in engine control modules exposed to alternator load dump events. IC Role / Device Role / Timing Role: Unidirectional clamping diode placed between battery input and downstream DC/DC converter input. Use Value: Limits transient voltage to ≤64.5 V during 4600 W surges, preventing latch-up or gate oxide damage in 3.3 V/5 V logic ICs. | Use Scenario: Shields constant-current LED driver ICs and MOSFET switches in adaptive front lighting systems. IC Role / Device Role / Timing Role: Parallel-connected TVS on 12 V supply rail upstream of buck controller and LED string. Use Value: Absorbs 10 ms exponential load dump energy without degradation, preserving driver IC lifetime at +125 °C ambient. |
| Body Control Module Power Input | Start-Stop System Battery Interface |
Use Scenario: Safeguards LIN transceivers, EEPROM, and power management ICs in door module ECUs. IC Role / Device Role / Timing Role: Primary overvoltage clamp on fused 12 V input, positioned before reverse-polarity protection FET. Use Value: Maintains <10 µA leakage at 40 V VWM, minimizing standby current drain in always-on vehicle networks. | Use Scenario: Protects bidirectional DC/DC converters and supercapacitor charge controllers in 12 V start-stop architectures. IC Role / Device Role / Timing Role: Bidirectional surge suppression achieved via back-to-back configuration (two ALS6W40A units). Use Value: Enables reliable operation under repeated cold-crank and load dump cycles while sustaining 175 °C junction temperature. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar load dump protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40A | DO-214AC package; 400 W PPPM; 64.5 V VC at 3.1 A - 14× lower surge capacity | Rated only for low-energy transients (ISO7637-2 Pulse 1/2a); unsuitable for Load Dump (Pulse 5a) | Select only for non-load-dump circuits where space or cost constraints override energy-handling needs. |
| SMCJ40A | DO-214AB package; 1500 W PPPM; 64.5 V VC at 23.3 A - 3× lower peak power than ALS6W40A | Meets ISO7637-2 Pulse 5a only at reduced temperature derating; not AEC-Q101 qualified | Acceptable for industrial 12 V systems lacking automotive qualification requirements, but insufficient for OEM ECU designs. |
Compared with SMAJ40A and SMCJ40A, ALS6W40A uniquely combines AEC-Q101 qualification, DO-218 thermal performance, and full 4600 W load dump capability - enabling single-device protection in high-reliability automotive power inputs without parallel stacking or thermal derating.
Availability
ALS6W40A is available at Aetrix Electronics and suitable for automotive ECU protection, LED lighting driver interfaces, body control module power inputs, and start-stop system battery interfaces requiring stable component supply across extended temperature and surge conditions.
Supply support for ALS6W40A 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 semiconductor company specializing in discrete, analog, and mixed-signal solutions for automotive, industrial, computing, and consumer markets.
The ALS6WxxA series is part of Diodes' AEC-Q101-qualified automotive TVS portfolio, designed specifically for high-energy load dump suppression in 12 V/24 V vehicle electrical systems.
FAQ
What is the polarity configuration and heatsink connection for ALS6W40A?
The ALS6W40A is a unidirectional TVS diode with the anode electrically connected to the metal heatsink tab. The cathode is marked by a bar on the molded body and is the lead terminal. Mounting the tab to a large copper pour provides both thermal conduction and low-inductance return path for surge current.
Does ALS6W40A meet ISO7637-2 Pulse 5a requirements across its full temperature range?
Yes - ALS6W40A is validated per ISO7637-2 Load Dump Pulse 5a (10 ms exponential) at −40 °C, 25 °C, and +125 °C. Its 4600 W peak power rating and 175 °C maximum junction temperature ensure compliance without external derating in under-hood environments.
Can ALS6W40A be used in bidirectional surge protection configurations?
Yes - two ALS6W40A devices can be connected anode-to-anode (back-to-back) to provide symmetrical clamping for AC-coupled or reversible power lines. This configuration achieves ±64.5 V clamping and supports start-stop system battery interfaces where voltage polarity may reverse during cranking.
What is the maximum allowable soldering temperature and duration for ALS6W40A?
ALS6W40A is rated for lead-free reflow soldering at 260 °C maximum for 10 seconds, per J-STD-020. Its DO-218 package passes MSL Level 1 classification, meaning it may be stored indefinitely at ≤30 °C/60% RH without baking prior to assembly.
ALS6W40A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- DO-218AB
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 71A
- Power - Peak Pulse:
- 4600W (4.6kW)
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-218
ALS6W40A FAQ
1.How can I place an order for ALS6W40A through Aetrix?
Please submit a Request for Quotation (RFQ) for ALS6W40A on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for ALS6W40A reliable?
The price and inventory of ALS6W40A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ALS6W40A is usually 5 days.
3.What payment methods are accepted for ALS6W40A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ALS6W40A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ALS6W40A?
ALS6W40A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ALS6W40A order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for ALS6W40A?
For technical support, including ALS6W40A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ALS6W40A requirements.
6.How does Aetrix verify that ALS6W40A is sourced from the original manufacturer or authorized distributors?
All ALS6W40A products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ALS6W40A meets industry standards.
7.What is the process for return or replacement of ALS6W40A?
All ALS6W40A units undergo pre-shipment inspection (PSI). If there is an issue with ALS6W40A, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The ALS6W40A part is unused and in its original packaging.
Return procedure for ALS6W40A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ALS6W40A Tags
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