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Diodes Incorporated ALS5W12A
- Part No.:
- ALS5W12A
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
ALS5W12A.pdf
- Description:
- Transient Voltage Suppressor PP
- Quantity:
- Payment:
- Shipping:
Inventory:7,525
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Product details
Overview
ALS5W12A from Diodes Incorporated is a unidirectional surface-mount load dump transient voltage suppressor in DO-218 package, rated for 12 V stand-off voltage (VWM), 13.3–14.7 V breakdown (VBR), 3600 W peak pulse power (10/1000 µs), and 500 A forward surge current - designed specifically for automotive ECU load dump protection where high-temperature stability and low clamping voltage (19.9 V at 181 A) are critical.
For engineers reviewing the ALS5W12A datasheet, ALS5W12A pinout, ALS5W12A application, or ALS5W12A equivalent, this device serves as a primary clamping diode in 12 V automotive power systems requiring AEC-Q101 qualification, ISO7637-2/ISO16750-2 compliance, and robust thermal performance up to +175 °C junction temperature.
Technical Context
The ALS5W12A operates as a unidirectional TVS diode with anode-connected heatsink configuration, optimized for fast response to load dump transients (exponential 10 ms waveform). Its low thermal resistance enables sustained 2800 W dissipation under 10/10,000 µs surge conditions and maintains stable clamping performance across –55 °C to +175 °C operating range.
It features a maximum forward voltage of 2.0 V at 100 A (8.3 ms half-sine), <10 µA reverse leakage at 12 V and 25 °C, and <150 µA at 12 V and 175 °C - ensuring minimal standby power loss and reliable high-temperature operation in engine bay environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12.0 V - Stand-off voltage threshold before conduction; defines maximum continuous reverse operating voltage in 12 V automotive systems. |
| VBR (min/max) | 13.3 V / 14.7 V - Breakdown voltage range at 5 mA test current; ensures consistent turn-on behavior across production lots. |
| VC @ IPPM | 19.9 V at 181 A (10/1000 µs) - Clamping voltage during worst-case surge; limits downstream IC stress below 20 V. |
| PPPM (10/1000 µs) | 3600 W - Peak pulse power handling; supports full ISO7637-2 Load Dump Test Pulse 5a without failure. |
| IFSM | 500 A - Non-repetitive forward surge rating (8.3 ms); withstands high-current inductive kickback from solenoids or motors. |
| TJ Range | –55 °C to +175 °C - Extended junction temperature range; enables placement near heat sources in under-hood ECUs. |
| Polarity | Unidirectional - Anode tied to heatsink; requires correct PCB layout with thermal pad connected to system ground or chassis. |
Pinout & Package
Package: DO-218 plastic outline - surface-mount, heatsink-integrated case with matte tin-plated terminals; polarity marked by cathode bar; heatsink terminal functions as anode.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Heatsink Pad) | Main current path input / thermal interface | Electrically and thermally connected to PCB copper pour; must be soldered to large thermal pad for 260 °C reflow and thermal management. |
| Cathode (Top Terminal) | Clamped output / surge return path | Connected to protected rail (e.g., 12 V battery line); carries full surge current during load dump events. |
Key Features
| Feature | Design Value |
|---|---|
| Automotive qualification | AEC-Q101 qualified and PPAP capable - meets OEM requirements for production automotive electronics. |
| Surge standard compliance | Fully compliant with ISO7637-2 Pulse 5a and ISO16750-2 load dump tests - validated for real-world vehicle electrical environments. |
| Thermal robustness | Rated for 175 °C junction temperature and 260 °C soldering - supports under-hood placement without derating. |
| Low clamping ratio | VC/VWM = 1.66 (19.9 V / 12 V) - minimizes overvoltage stress on downstream DC-DC converters and microcontrollers. |
| Green manufacturing | Halogen- and antimony-free, RoHS 3 compliant - satisfies global environmental regulations and OEM sustainability mandates. |
Applications
| Engine Control Unit (ECU) Protection | Body Control Module (BCM) Power Rail |
|---|---|
Use Scenario: Protects 12 V supply input of engine control units during alternator load dump events in gasoline/diesel vehicles. IC Role / Device Role / Timing Role: Primary clamping diode placed between battery feed and input filter capacitor; conducts surge current away from LDOs and MCU power pins. Use Value: Limits transient voltage to ≤19.9 V, preventing latch-up or permanent damage to 28 nm automotive MCUs operating at 3.3 V or 5 V rails. | Use Scenario: Shields BCM power inputs from load dump surges induced by headlight or wiper motor switching. IC Role / Device Role / Timing Role: Unidirectional TVS mounted directly at BCM connector entry point; absorbs energy before it reaches PMIC and CAN transceivers. Use Value: Enables use of smaller input capacitors (≤100 µF) due to low clamping voltage and high surge margin, reducing BOM cost and board area. |
| ADAS Camera Power Supply | Electric Power Steering (EPS) Module |
Use Scenario: Safeguards 12 V input of rear-view or surround-view camera modules exposed to load dump in parking/ignition cycles. IC Role / Device Role / Timing Role: First-line transient suppressor upstream of buck converter; clamps within 1 ns to prevent reset or image corruption. Use Value: Maintains <10 µA leakage at 12 V and 125 °C - avoids quiescent current drift that could trigger false wake-up in always-on vision systems. | Use Scenario: Protects EPS module power stage from load dump during sudden battery disconnect or alternator regulation faults. IC Role / Device Role / Timing Role: Mounted on high-current power plane adjacent to MOSFET half-bridge; shunts surge into chassis ground via heatsink pad. Use Value: Withstands 500 A single-pulse surge and dissipates 3600 W peak - eliminates need for parallel TVS devices or external heat sinks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar load dump protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12A | Lower PPPM (400 W), SMA package, 200 A IFSM, higher VC (20.1 V) | Not suitable for full ISO7637-2 Pulse 5a; limited to low-energy transients in non-critical modules | Select only for cost-sensitive interior modules with no direct battery connection. |
| SMCJ12A | Higher PPPM (1500 W), SMC package, 200 A IFSM, VC = 19.9 V | Meets ISO7637-2 Pulse 5b but not 5a; insufficient for full alternator dump in 12 V systems | Use where space allows larger SMC footprint and peak power demand is ≤1500 W. |
Compared with SMAJ12A and SMCJ12A, ALS5W12A delivers 2.4× and 2.4× higher peak pulse power respectively, supports 2.5× higher surge current, and maintains identical clamping voltage while enabling DO-218's superior thermal coupling - making it the only choice for AEC-Q101-compliant, full-spec load dump protection in modern 12 V ECUs.
Availability
ALS5W12A is available at Aetrix Electronics and suitable for automotive ECU protection, body control module hardening, ADAS camera power conditioning, and electric power steering module design requiring stable component supply and long-term lifecycle support.
Supply support for ALS5W12A 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 belongs to Diodes' Automotive TVS portfolio, engineered specifically to meet stringent ISO7637-2 and AEC-Q101 requirements for load dump suppression in 12 V vehicle electrical systems.
FAQ
What is the recommended PCB layout for optimal thermal performance?
The DO-218 package requires a minimum 200 mm² copper pour connected to the anode (heatsink) pad, with ≥4 thermal vias (0.3 mm diameter) to inner ground planes. Cathode trace width must be ≥1.5 mm to handle 500 A surge without fusing. Avoid solder mask over thermal pads.
Does ALS5W12A require derating at elevated ambient temperatures?
Yes - power derating begins at 25 °C case temperature per Figure 1. At 125 °C case, maximum PPPM drops to ~1800 W (50% of rated 3600 W). Designers must calculate actual case temperature using RθJC = 0.25 °C/W and ensure heatsink design maintains TJ ≤ 175 °C.
How does ALS5W12A compare to bidirectional TVS diodes in load dump applications?
Unidirectional configuration provides lower clamping voltage (19.9 V vs. ≥22 V for bidirectional), faster response, and higher surge current capability. Bidirectional variants are unnecessary for load dump - which is inherently unidirectional positive surge - and introduce higher leakage and capacitance.
Is lead-free reflow compatible with the DO-218 package?
Yes - the device is qualified for lead-free reflow per J-STD-020 MSL Level 1, with peak temperature tolerance up to 260 °C for 10 seconds. Matte tin plating ensures solderability per MIL-STD-750 Method 2026 and JESD22-B102.
ALS5W12A 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):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 19.9V
- Current - Peak Pulse (10/1000µs):
- 181A
- 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
ALS5W12A FAQ
1.How can I place an order for ALS5W12A through Aetrix?
Please submit a Request for Quotation (RFQ) for ALS5W12A 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 ALS5W12A reliable?
The price and inventory of ALS5W12A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ALS5W12A is usually 5 days.
3.What payment methods are accepted for ALS5W12A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ALS5W12A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ALS5W12A?
ALS5W12A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ALS5W12A 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 ALS5W12A?
For technical support, including ALS5W12A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ALS5W12A requirements.
6.How does Aetrix verify that ALS5W12A is sourced from the original manufacturer or authorized distributors?
All ALS5W12A 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 ALS5W12A meets industry standards.
7.What is the process for return or replacement of ALS5W12A?
All ALS5W12A units undergo pre-shipment inspection (PSI). If there is an issue with ALS5W12A, 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 ALS5W12A part is unused and in its original packaging.
Return procedure for ALS5W12A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ALS5W12A Tags
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