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Diodes Incorporated ALS5W20A
- Part No.:
- ALS5W20A
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
ALS5W20A.pdf
- Description:
- Transient Voltage Suppressor PP
- Quantity:
- Payment:
- Shipping:
Inventory:3,881
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Product details
Overview
ALS5W20A from Diodes Incorporated is a unidirectional surface-mount load dump transient voltage suppressor in DO-218 package, rated for 20 V stand-off voltage, 22.2–24.5 V breakdown, 32.4 V clamping at 111 A peak pulse current, and 3600 W peak pulse power (10/1000 µs). It serves as a clamping diode for automotive ECU protection against ISO 7637-2 and ISO 16750-2 load dump transients.
For engineers reviewing the ALS5W20A datasheet, ALS5W20A pinout, ALS5W20A application, or ALS5W20A equivalent, key selection criteria include its 20 V VWM, 32.4 V VC at 111 A, unidirectional polarity, DO-218 thermal performance, and AEC-Q101 qualification for under-hood automotive use.
Technical Context
This device operates as a unidirectional TVS diode optimized for high-energy automotive load dump suppression. Its silicon avalanche structure delivers precise clamping with low dynamic impedance, enabling rapid voltage limiting during 10 ms exponential surges up to 2800 W at elevated case temperatures.
The DO-218 package provides low thermal resistance (RθJC ≈ 1.2 °C/W) and supports 260 °C soldering. Polarity is defined by heatsink-as-anode configuration, requiring correct PCB layout to ensure proper forward conduction path during transient events.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20.0 V - Maximum continuous reverse operating voltage before leakage exceeds 10 µA |
| VBR (min/max) | 22.2 V / 24.5 V - Breakdown occurs within this range at 5 mA test current, defining turn-on threshold |
| VC @ IPPM | 32.4 V - Clamped voltage at 111 A peak pulse current (10/1000 µs), limiting downstream stress |
| PPPM (10/1000 µs) | 3600 W - Peak surge power handling capability under standard short-duration waveform |
| IFSM | 500 A - Forward surge rating (8.3 ms half-sine), supporting high-current inrush during fault recovery |
| TJ Range | −55 °C to +175 °C - Full operational junction temperature range, validated per AEC-Q101 |
Pinout & Package
DO-218 plastic package with integrated heatsink; anode terminal is the metal heatsink base, cathode is the molded top-side metallized stripe (cathode bar). Matte tin-plated terminals meet MIL-STD-750 Method 2026 and JESD22-B102.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Heatsink) | Forward conduction path input | Electrically connected to metal heatsink base; must be mounted to PCB copper pour for thermal and electrical integrity |
| Cathode (Top stripe) | Clamping output / transient sink | Molded cathode bar on top surface; connects to protected line (e.g., battery rail) to shunt surge to ground/anode |
Key Features
| Feature | Design Value |
|---|---|
| ISO 7637-2 & ISO 16750-2 compliance | Validated for automotive load dump immunity testing across temperature and waveform variations |
| AEC-Q101 qualification | Qualified for automotive under-hood applications including engine control modules and lighting drivers |
| Low clamping ratio (VC/VBR) | ~1.39 - Enables tighter system-level overvoltage margin without sacrificing energy handling |
| MSL Level 1 rating | Unlimited floor life at ≤30 °C/60% RH, eliminating bake requirements prior to reflow |
| Halogen- and antimony-free "Green" construction | Meets RoHS 3 (2015/863/EU) with Br+Cl <1500 ppm and Sb <1000 ppm |
Applications
| Engine Control Unit Protection | LED Headlamp Driver Protection |
|---|---|
Use Scenario: Protects microcontroller power rails in engine ECUs exposed to 12 V battery load dump surges up to 40 V. IC Role / Device Role / Timing Role: Clamping diode placed between battery input and DC/DC converter input to limit transient voltage before regulation stage. Use Value: Limits peak voltage to 32.4 V at 111 A, preventing damage to 36 V-rated input capacitors and LDOs. | Use Scenario: Shields constant-current LED driver ICs in adaptive front lighting systems during alternator load dump events. IC Role / Device Role / Timing Role: Unidirectional TVS connected anode-to-ground, cathode-to-LED supply rail to clamp positive transients only. Use Value: Maintains <33 V rail during 3600 W surge, preserving PWM timing accuracy and avoiding LED current foldback. |
| Body Control Module Power Input | Start-Stop System Battery Interface |
Use Scenario: Guards power management ICs in BCMs handling door lock, window lift, and HVAC functions. IC Role / Device Role / Timing Role: Primary transient suppressor on 12 V main input, upstream of fuse and pre-regulator. Use Value: Withstands repeated 10 ms exponential surges up to 2800 W at 150 °C case temperature per ISO 16750-2. | Use Scenario: Protects bidirectional DC/DC converters in 12 V start-stop systems during engine cranking and alternator restart transients. IC Role / Device Role / Timing Role: Anode-grounded TVS on battery side of buck-boost controller to absorb regenerative spikes. Use Value: Enables reliable operation at −40 °C to +175 °C junction temperature, critical for under-hood mounting near starter motor. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional load dump suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ20A | Lower PPPM (400 W), SMA package, higher RθJA, VC = 32.4 V @ 12.3 A | Not suitable for ISO 7637-2 load dump; limited to lower-energy transients | Select only for non-automotive 12 V systems with <500 W surge exposure |
| SMCJ20A | PPPM = 1500 W, SMC package, VC = 32.4 V @ 46.5 A, RθJC ≈ 2.5 °C/W | Meets ISO 7637-2 Pulse 5a but not full load dump; insufficient for 3600 W requirement | Acceptable for cost-sensitive industrial 12 V inputs where peak power is capped at 1500 W |
Compared with SMAJ20A and SMCJ20A, ALS5W20A delivers 2.4× and 2.4× higher peak pulse power respectively, with DO-218's superior thermal dissipation enabling sustained operation at 175 °C junction temperature-critical for automotive under-hood deployment.
Availability
ALS5W20A is available at Aetrix Electronics and suitable for automotive engine control units, LED headlamp drivers, body control modules, and start-stop system battery interfaces requiring stable component supply and AEC-Q101-compliant surge protection.
Supply support for ALS5W20A 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 consumer markets.
The ALS5WxxA series is part of Diodes' automotive-grade TVS portfolio, engineered specifically for ISO 7637-2 and ISO 16750-2 load dump compliance in harsh under-hood environments.
FAQ
What is the maximum clamping voltage of ALS5W20A under load dump conditions?
The maximum clamping voltage VC is 32.4 V when subjected to a 111 A peak pulse current (10/1000 µs waveform), as specified in the Electrical Characteristics table. This value is measured at TA = 25 °C and represents worst-case clamping during standardized surge testing.
Can ALS5W20A be used in bidirectional surge protection circuits?
No-ALS5W20A is a unidirectional TVS diode with anode-connected heatsink and cathode stripe. It conducts only during positive transients relative to ground. For bidirectional protection, two devices must be used in series-opposing configuration or a dedicated bidirectional TVS selected.
How does the DO-218 package improve thermal performance over SMA or SMC packages?
The DO-218 package integrates a large metal heatsink directly into the anode terminal, achieving RθJC ≈ 1.2 °C/W-nearly half that of SMC (≈2.5 °C/W). This enables 3600 W surge dissipation at higher case temperatures and extends safe operating life in under-hood automotive locations.
Is ALS5W20A compliant with lead-free assembly standards?
Yes-ALS5W20A features matte tin plating compatible with Pb-free reflow processes, qualified to JEDEC J-STD-020 MSL Level 1, and rated for 260 °C peak temperature (10 seconds). It meets RoHS 3 (2015/863/EU) and Diodes' Halogen- and Antimony-free "Green" definition.
ALS5W20A 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):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 32.4V
- Current - Peak Pulse (10/1000µs):
- 111A
- Power - Peak Pulse:
- 3600W (3.6kW)
- 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
ALS5W20A FAQ
1.How can I place an order for ALS5W20A through Aetrix?
Please submit a Request for Quotation (RFQ) for ALS5W20A 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 ALS5W20A reliable?
The price and inventory of ALS5W20A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ALS5W20A is usually 5 days.
3.What payment methods are accepted for ALS5W20A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ALS5W20A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ALS5W20A?
ALS5W20A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ALS5W20A 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 ALS5W20A?
For technical support, including ALS5W20A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ALS5W20A requirements.
6.How does Aetrix verify that ALS5W20A is sourced from the original manufacturer or authorized distributors?
All ALS5W20A 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 ALS5W20A meets industry standards.
7.What is the process for return or replacement of ALS5W20A?
All ALS5W20A units undergo pre-shipment inspection (PSI). If there is an issue with ALS5W20A, 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 ALS5W20A part is unused and in its original packaging.
Return procedure for ALS5W20A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ALS5W20A Tags
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