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Diodes Incorporated ALS5W28A
- Part No.:
- ALS5W28A
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
ALS5W28A.pdf
- Description:
- Transient Voltage Suppressor PP
- Quantity:
- Payment:
- Shipping:
Inventory:3,960
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Product details
Overview
ALS5W28A from Diodes Incorporated is a unidirectional surface-mount load dump transient voltage suppressor diode in DO-218 package, rated for 28.0 V standoff voltage (VWM), 31.1–34.4 V breakdown (VBR), 45.4 V clamping at 79 A peak pulse current, and 3600 W peak pulse power (10/1000 µs). It serves as a clamping diode for automotive ECU load dump protection.
For engineers reviewing the ALS5W28A datasheet, ALS5W28A pinout, ALS5W28A application, or ALS5W28A equivalent, key selection criteria include its AEC-Q101 qualification, ISO7637-2/ISO16750-2 compliance, 175 °C junction temperature rating, unidirectional polarity with heatsink-anode configuration, and DO-218 mechanical outline compatibility with high-temperature reflow (260 °C/10 s).
Technical Context
This device operates as a unidirectional TVS diode optimized for automotive load dump transients-clamping inductive kickback surges from alternator regulation failure. Its low thermal resistance and high surge capability (500 A IFSM) enable robust energy absorption without thermal runaway under repeated 10 ms exponential waveforms.
Designed for direct mounting to heatsinks (anode = heatsink), it leverages the DO-218 package's low RθJC to sustain 3600 W peak power at TC = 25 °C, derating linearly to ~1100 W at 150 °C per Fig.1. Clamping performance is specified at 79 A (10/1000 µs), delivering 45.4 V maximum VC-critical for protecting downstream 3.3 V/5 V/12 V logic and power rails.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 28.0 V - Maximum continuous reverse operating voltage before conduction begins; sets system nominal rail margin. |
| VBR (min/max) | 31.1 V / 34.4 V - Breakdown threshold range at 5 mA test current; defines turn-on consistency across production lot. |
| VC @ IPPM | 45.4 V @ 79 A - Clamped voltage during 10/1000 µs surge; determines maximum stress on protected ICs. |
| PPPM (10/1000 µs) | 3600 W - Peak pulse power handling; enables single-device protection against severe ISO7637-2 Pulse 5a/b events. |
| IFSM | 500 A - 8.3 ms half-sine surge current rating; supports high-energy inductive switching without bond wire fusing. |
| TJ Range | −55 °C to +175 °C - Extended junction temperature range; ensures reliability in under-hood automotive environments. |
Pinout & Package
ALS5W28A uses the DO-218 surface-mount plastic package with anode-connected heatsink tab and cathode marked by a bar. The two-terminal configuration requires external heatsinking for sustained power dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Heatsink Tab) | Power return path and thermal interface | Must be soldered to copper pour or heatsink; electrically connects to system ground or chassis return in load dump configurations. |
| Cathode (Bar-marked Lead) | Transient voltage sensing and clamping node | Connected to protected line (e.g., battery rail); conducts surge current to anode when VIN exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive under-hood use including temperature cycling, humidity, and mechanical shock per JESD22 standards. |
| ISO7637-2 & ISO16750-2 compliant | Meets Pulse 5a (load dump) requirements up to 100 V test amplitude with 10 ms exponential decay waveform. |
| Low thermal resistance (RθJC) | Enables >1100 W power dissipation at 150 °C case temperature-critical for compact ECU layouts with limited airflow. |
| Lead-free, halogen-free "Green" construction | Complies with RoHS 3 (2015/863/EU) and JEDEC J-STD-020 MSL Level 1; supports lead-free reflow up to 260 °C/10 s. |
Applications
| Automotive Engine Control Unit (ECU) Protection | Commercial Vehicle Lighting Control |
|---|---|
Use Scenario: Protecting microcontroller power rails and CAN transceivers from alternator load dump surges during battery disconnect events. IC Role / Device Role / Timing Role: Unidirectional clamping diode placed between battery rail and ground, conducting only during overvoltage transients. Use Value: Limits peak rail voltage to ≤45.4 V, preventing latch-up or permanent damage to 5 V/3.3 V logic and 12 V analog front-ends. | Use Scenario: Safeguarding LED driver ICs and MOSFET switches in heavy-duty trailer lighting modules exposed to 24 V system transients. IC Role / Device Role / Timing Role: Primary transient suppression element on 24 V input bus, absorbing >3 kW pulses without degradation. Use Value: Maintains <10 µA leakage at 28 V, minimizing standby current drain while enabling reliable operation at −40 °C to +125 °C ambient. |
| Off-Highway Equipment Power Distribution | Hybrid Electric Vehicle (HEV) 12 V Auxiliary System |
Use Scenario: Securing solenoid driver circuits and sensor interfaces in agricultural machinery subject to frequent engine cranking and alternator regulation faults. IC Role / Device Role / Timing Role: High-current surge shunt connected directly to main power bus, with heatsink-integrated anode for thermal management. Use Value: Withstands 500 A non-repetitive forward surge, eliminating need for parallel devices in 100 A+ distribution nodes. | Use Scenario: Protecting DC-DC converter inputs and infotainment power supplies in HEV auxiliary 12 V networks sharing battery with high-voltage traction systems. IC Role / Device Role / Timing Role: Load dump clamp on isolated 12 V rail, coordinated with upstream DC-DC controller fault response. Use Value: Delivers 3600 W peak power handling at 25 °C case, ensuring immunity to worst-case ISO16750-2 Pulse 5b (100 V, 10 ms) events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar load dump protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ28A | Lower PPPM (400 W), SMA package, 300 A IFSM, VC = 45.4 V @ 8.9 A | Not suitable for full-load dump; limited to lower-energy transients in non-automotive or low-power modules. | Select only if system surge energy is <100 mJ and thermal budget permits higher RθJA. |
| SMCJ28A | Higher PPPM (1500 W), SMC package, 200 A IFSM, VC = 45.4 V @ 33 A | Insufficient for ISO7637-2 Pulse 5a compliance above 30 V test levels; lacks AEC-Q101 certification. | Acceptable for industrial control where automotive qualification is not required and peak power <1500 W. |
Compared with SMAJ28A and SMCJ28A, ALS5W28A delivers 2.4× and 2.4× higher peak pulse power respectively, full AEC-Q101 qualification, and DO-218 thermal performance enabling direct heatsink mounting-making it the only option rated for full automotive load dump compliance at 28 V system level.
Availability
ALS5W28A is available at Aetrix Electronics and suitable for automotive ECU protection, commercial vehicle lighting control, off-highway equipment power distribution, and HEV 12 V auxiliary systems requiring stable component supply across extended temperature and surge conditions.
Supply support for ALS5W28A 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 ALS5WxxA series is part of Diodes' Automotive TVS portfolio, engineered specifically for ISO7637-2/ISO16750-2 load dump protection in harsh under-hood environments with minimal footprint and maximum thermal efficiency.
FAQ
What is the maximum clamping voltage of ALS5W28A under standard test conditions?
The maximum clamping voltage (VC) is 45.4 V when subjected to a 10/1000 µs waveform with a peak pulse current (IPPM) of 79 A at TA = 25 °C. This value is measured per JEDEC standards and guarantees protection headroom for 24 V automotive systems operating up to 28 V nominal.
Is ALS5W28A compatible with lead-free reflow soldering processes?
Yes-ALS5W28A meets J-STD-020 MSL Level 1 and is qualified for lead-free reflow up to 260 °C for 10 seconds. Its matte tin-plated terminals comply with MIL-STD-750 Method 2026 and JESD22-B102, ensuring reliable wetting and intermetallic formation without voiding or dewetting.
How does the DO-218 package improve thermal performance compared to SMA or SMC packages?
The DO-218 package features an integrated anode heatsink tab that provides direct thermal conduction to PCB copper or external heatsinks, achieving significantly lower RθJC. This allows ALS5W28A to dissipate 3600 W at 25 °C case temperature-over twice the capability of SMCJ28A (1500 W) in the same footprint-without thermal throttling.
Does ALS5W28A require external circuitry such as series resistors or timing capacitors?
No-ALS5W28A is a two-terminal passive device requiring no external components. Its clamping action is intrinsic and instantaneous (<1 ns response time). Designers must ensure adequate PCB copper area for the anode tab and maintain ≥0.5 mm clearance from adjacent traces to prevent arcing during 100 V transients.
ALS5W28A 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):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.4V
- Current - Peak Pulse (10/1000µs):
- 79A
- 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
ALS5W28A FAQ
1.How can I place an order for ALS5W28A through Aetrix?
Please submit a Request for Quotation (RFQ) for ALS5W28A 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 ALS5W28A reliable?
The price and inventory of ALS5W28A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ALS5W28A is usually 5 days.
3.What payment methods are accepted for ALS5W28A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ALS5W28A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ALS5W28A?
ALS5W28A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ALS5W28A 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 ALS5W28A?
For technical support, including ALS5W28A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ALS5W28A requirements.
6.How does Aetrix verify that ALS5W28A is sourced from the original manufacturer or authorized distributors?
All ALS5W28A 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 ALS5W28A meets industry standards.
7.What is the process for return or replacement of ALS5W28A?
All ALS5W28A units undergo pre-shipment inspection (PSI). If there is an issue with ALS5W28A, 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 ALS5W28A part is unused and in its original packaging.
Return procedure for ALS5W28A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ALS5W28A Tags
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