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Diodes Incorporated ALS8W20A
- Part No.:
- ALS8W20A
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
ALS8W20A.pdf
- Description:
- Transient Voltage Suppressor PP
- Quantity:
- Payment:
- Shipping:
Inventory:3,700
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Product details
Overview
ALS8W20A from Diodes Incorporated is a unidirectional surface-mount load dump transient voltage suppressor in DO-218 package, rated for 20 V stand-off voltage (VWM), 22.2–24.5 V breakdown (VBR), 6600 W peak pulse power (10/1000 µs), and 204 A peak pulse current, designed for automotive ECU protection against ISO 7637-2 load dump transients.
For engineers reviewing the ALS8W20A datasheet, ALS8W20A pinout, ALS8W20A application, or ALS8W20A equivalent, key selection criteria include clamping voltage (32.4 V at IPPM), thermal stability up to +175 °C junction temperature, low forward voltage (≤1.8 V at 100 A), and compliance with AEC-Q101 requirements for automotive-grade reliability.
Technical Context
The ALS8W20A operates as a unidirectional avalanche diode optimized for high-energy transient suppression in 12 V automotive systems. Its DO-218 package provides low thermal resistance and supports 700 A non-repetitive forward surge current (IFSM) under 8.3 ms half-sine waveform.
It meets ISO 7637-2 and ISO 16750-2 load dump test conditions with clamping performance validated across case temperatures from −55 °C to +175 °C. The device exhibits ≤10 µA reverse leakage at VWM and ≤150 µA at +175 °C, ensuring stable operation in high-temperature engine bay environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20.0 V - Maximum continuous reverse operating voltage before conduction begins |
| VBR (min/max) | 22.2 V / 24.5 V - Breakdown voltage range at 5 mA test current; defines turn-on threshold consistency |
| VC @ IPPM | 32.4 V - Clamping voltage at 204 A peak pulse; determines protected circuit's maximum overvoltage stress |
| PPPM (10/1000 µs) | 6600 W - Peak pulse power handling capability; enables robust protection against fast, high-energy transients |
| IFSM | 700 A - Non-repetitive forward surge current rating; supports high-current inductive switching events |
| TJ Range | −55 °C to +175 °C - Operating junction temperature range; qualified for under-hood automotive placement |
| Leakage @ VWM, +175 °C | ≤150 µA - Low high-temperature reverse leakage ensures minimal standby power loss and system reliability |
Pinout & Package
Package: DO-218 - Surface-mount plastic package with heatsink-anode polarity, 2.74 g mass, UL 94V-0 flammability rating, and matte tin-plated terminals compliant with J-STD-002 and MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Heatsink) | Current entry terminal during clamping | Electrically connected to metal heatsink base; must be mounted to PCB copper pour for thermal management |
| Cathode (Bar-marked lead) | Current exit terminal during clamping | Marked with cathode band; connects to protected line (e.g., battery rail); defines unidirectional conduction direction |
Key Features
| Feature | Design Value |
|---|---|
| High peak pulse power handling | 6600 W (10/1000 µs) enables single-device protection against severe automotive load dump events without cascading failure |
| Low clamping voltage | 32.4 V at 204 A limits downstream IC overvoltage stress below typical 36 V automotive system derating thresholds |
| Automotive qualification | AEC-Q101 qualified, manufactured in IATF 16949 certified facilities, and PPAP-capable for OEM production traceability |
| Thermal robustness | Rated for +175 °C junction operation with <1.0 °C/W typical junction-to-case thermal resistance, supporting compact under-hood layouts |
Applications
| Engine Control Unit (ECU) Protection | Body Control Module (BCM) Power Rail |
|---|---|
Use Scenario: Installed on 12 V battery input of engine control units exposed to alternator load dump surges during ignition cycling. IC Role / Device Role / Timing Role: Unidirectional TVS diode providing primary overvoltage clamping at the power entry point. Use Value: Limits transient voltage to ≤32.4 V, protecting downstream PMICs, microcontrollers, and CAN transceivers from damage per ISO 7637-2 Pulse 5a. | Use Scenario: Placed on main supply rail of body control modules powering lighting, door locks, and HVAC actuators. IC Role / Device Role / Timing Role: High-energy transient suppressor absorbing inductive kickback from relay and motor loads. Use Value: Withstands 700 A surge current and maintains ≤10 µA leakage at 20 V, preserving low-power sleep mode integrity. |
| Advanced Driver Assistance Systems (ADAS) Camera Power | Electric Power Steering (EPS) Module |
Use Scenario: Mounted on power input of front-facing ADAS cameras subject to repeated cold-cranking and load dump events. IC Role / Device Role / Timing Role: Primary clamping device safeguarding image sensor and ISP power domains. Use Value: Stable 22.2–24.5 V breakdown ensures consistent turn-on timing across temperature, preventing false triggering or delayed response. | Use Scenario: Integrated into EPS module power stage to protect gate drivers and motor controllers from battery-side transients. IC Role / Device Role / Timing Role: High-current unidirectional suppressor placed between battery and DC/DC converter input. Use Value: 6600 W pulse rating and 204 A clamping current sustain protection during simultaneous motor stall and load dump conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar load dump transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ20A | Lower PPPM (400 W), smaller SMA package, VC = 32.4 V at 12.3 A | Not suitable for ISO 7637-2 Pulse 5; limited to low-energy board-level transients | Select only for non-automotive, low-power subsystems where 6600 W capability is unnecessary |
| SM8S20A | Same DO-218 package, 6600 W rating, but VC = 34.4 V at 193 A and higher leakage (≤50 µA @ +175 °C) | Compatible for load dump but offers less stringent clamping margin vs. ALS8W20A's 32.4 V | Acceptable alternative when slightly higher clamping voltage is tolerable and same footprint is required |
Compared with SMAJ20A and SM8S20A, ALS8W20A delivers superior thermal margin (−55 °C to +175 °C), tighter VBR tolerance (22.2–24.5 V), and lower high-temperature leakage-making it the preferred choice for mission-critical automotive power rail protection where clamping precision and reliability are paramount.
Availability
ALS8W20A is available at Aetrix Electronics and suitable for automotive ECU protection, body control module power rails, ADAS camera power inputs, and electric power steering modules requiring stable component supply and AEC-Q101-compliant transient suppression.
Supply support for ALS8W20A 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 IATF 16949-certified manufacturing.
The ALS8W series belongs to Diodes' automotive-grade transient voltage suppressor product line, engineered specifically for ISO 7637-2 and ISO 16750-2 load dump compliance in 12 V vehicle electrical systems.
FAQ
What is the polarity configuration of ALS8W20A?
The ALS8W20A is a unidirectional TVS diode with anode connected to the heatsink tab and cathode marked by a bar on the lead. During transient events, current flows from anode to cathode, clamping positive overvoltages on the cathode-connected line. This configuration requires correct orientation on the PCB to avoid reverse-bias failure.
Does ALS8W20A meet AEC-Q101 qualification?
Yes, ALS8W20A is AEC-Q101 qualified and manufactured in IATF 16949 certified facilities. It undergoes stress testing including high-temperature operating life, temperature cycling, and humidity bias HAST to ensure reliability in automotive under-hood environments up to +175 °C junction temperature.
How does the DO-218 package improve thermal performance over SMA or SMC?
The DO-218 package features an integrated metal heatsink tab that provides direct thermal path to PCB copper, achieving ~1.0 °C/W junction-to-case thermal resistance-nearly 3× better than SMA packages. This enables sustained 6600 W pulse handling without thermal runaway, critical for repeated load dump events in automotive ECUs.
Can ALS8W20A be used in 24 V commercial vehicle systems?
No-ALS8W20A is specified for 20 V stand-off and 32.4 V clamping, making it suitable only for 12 V nominal automotive systems. For 24 V systems, Diodes recommends ALS8W40A (40 V VWM, 64.5 V VC) or ALS8W43A (43 V VWM, 69.4 V VC) to maintain adequate voltage margin above system operating range.
ALS8W20A 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):
- 204A
- Power - Peak Pulse:
- 6600W (6.6kW)
- 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
ALS8W20A FAQ
1.How can I place an order for ALS8W20A through Aetrix?
Please submit a Request for Quotation (RFQ) for ALS8W20A 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 ALS8W20A reliable?
The price and inventory of ALS8W20A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ALS8W20A is usually 5 days.
3.What payment methods are accepted for ALS8W20A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ALS8W20A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ALS8W20A?
ALS8W20A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ALS8W20A 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 ALS8W20A?
For technical support, including ALS8W20A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ALS8W20A requirements.
6.How does Aetrix verify that ALS8W20A is sourced from the original manufacturer or authorized distributors?
All ALS8W20A 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 ALS8W20A meets industry standards.
7.What is the process for return or replacement of ALS8W20A?
All ALS8W20A units undergo pre-shipment inspection (PSI). If there is an issue with ALS8W20A, 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 ALS8W20A part is unused and in its original packaging.
Return procedure for ALS8W20A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ALS8W20A Tags
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