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Vishay General Semiconductor - Diodes Division SM5S20A-E3/2D
- Part No.:
- SM5S20A-E3/2D
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-218AB
- Datasheet:
-
SM5S20A-E3/2D.pdf
- Description:
- TVS DIODE 20VWM 32.4VC DO218AB
- Quantity:
- Payment:
- Shipping:
Inventory:9,848
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Product details
Overview
SM5S20A-E3/2D from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor (TVS) diode designed for automotive load dump protection in 24 V systems. It features a 20 V standoff voltage (VWM), 32.4 V clamping voltage at 111 A peak pulse current, 3600 W peak pulse power (10/1000 µs), and AEC-Q101 qualification for under-hood applications.
For engineers reviewing the SM5S20A-E3/2D datasheet, SM5S20A-E3/2D pinout, SM5S20A-E3/2D application, or SM5S20A-E3/2D equivalent, key selection criteria include its DO-218AB package thermal resistance (RθJC = 1.0 °C/W), 175 °C junction rating, low leakage (<10 µA at VWM), and compliance with ISO7637-2 surge testing - critical for automotive power rail hardening.
Technical Context
The SM5S20A-E3/2D operates as a unidirectional avalanche diode with anode-connected heatsink configuration, enabling high-power transient energy absorption without polarity reversal. Its junction passivation and anisotropic rectifier technology deliver stable clamping performance across -55 °C to +175 °C operating range.
It is rated for 500 A non-repetitive forward surge current (IFSM, 8.3 ms half-sine) and exhibits low forward voltage drop (≤2.0 V at 100 A), supporting robust protection during sustained overvoltage events such as alternator load dump transients in vehicle electrical systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20.0 V - Maximum continuous reverse operating voltage before clamping 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 111 A peak pulse current; determines protected circuit's maximum stress level |
| PPPM (10/1000 µs) | 3600 W - Peak transient power handling capability; supports ISO7637-2 Load Dump Pulse 5a |
| TJ max | +175 °C - Enables placement near hot engine compartments without derating concerns |
| RθJC | 1.0 °C/W - Low thermal resistance from junction to case enables efficient heat transfer to PCB copper pour or heatsink |
| AEC-Q101 | Qualified - Meets automotive-grade reliability requirements for temperature cycling, HTRB, and ESD |
Pinout & Package
Package: DO-218AB - Surface-mount, single-anode/heatsink configuration with matte tin-plated leads; meets UL 94 V-0, MSL Level 1 (245 °C reflow), and JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Lead 1 | Anode | Main current entry point; connected to protected line (e.g., battery rail) |
| Lead 2 / Metal Heatsink | Cathode / Thermal Path | Electrically cathode and primary thermal interface; must be soldered to large copper area for thermal management |
Key Features
| Feature | Design Value |
|---|---|
| Junction passivated anisotropic rectifier | Enables stable, repeatable breakdown behavior over lifetime and temperature extremes |
| 175 °C junction rating | Supports direct mounting on engine control units and body control modules without external thermal derating |
| Low leakage (<10 µA at VWM) | Minimizes standby power loss in always-on automotive subsystems (e.g., CAN wake-up circuits) |
| ISO7637-2 compliant | Validated for Load Dump Pulse 5a (10 ms exponential waveform), meeting OEM-level surge immunity |
| DO-218AB mechanical robustness | Withstands mechanical stress from thermal cycling and vibration in automotive chassis environments |
Applications
| Engine Control Unit (ECU) Power Protection | Body Control Module (BCM) Input Protection |
|---|---|
Use Scenario: Protecting 24 V supply input of diesel/gasoline engine ECUs against alternator load dump surges up to 40 V. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between battery rail and DC-DC converter input. Use Value: Limits transient voltage to ≤32.4 V at 111 A, preventing damage to downstream regulators and microcontrollers. | Use Scenario: Safeguarding BCM power inputs exposed to switching noise from relays, motors, and lighting loads. IC Role / Device Role / Timing Role: Primary overvoltage clamp on fused 24 V feed prior to LDO and CAN transceivers. Use Value: Withstands repetitive 2800 W (10/10,000 µs) surges while maintaining <10 µA leakage at 20 V nominal operation. |
| Start-Stop System Battery Interface | Commercial Vehicle Telematics Power Rail |
Use Scenario: Securing start-stop system control electronics during repeated battery disconnect/reconnect events. IC Role / Device Role / Timing Role: Fast-response clamping device on main battery connection to prevent voltage overshoot during regenerative braking transitions. Use Value: AEC-Q101 qualification ensures reliability over 10,000+ thermal cycles typical in start-stop duty cycles. | Use Scenario: Hardening telematics gateway power input in trucks and buses subjected to harsh electrical environments. IC Role / Device Role / Timing Role: Front-end surge protector on OBD-II or auxiliary 24 V power connector. Use Value: DO-218AB package provides superior thermal dissipation vs. SMA/SMB, sustaining 5 W steady-state power on infinite heatsink. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ20A-E3/57T | Lower PPPM (400 W), SMA package, RθJC = 35 °C/W, same VWM/VBR range | Limited to lower-energy transients; unsuitable for ISO7637-2 Load Dump Pulse 5a | Select only for cost-sensitive non-automotive 24 V systems with <500 W surge requirements |
| TPSMD20A | Same DO-218AB package, 3600 W PPPM, but higher VC = 34.4 V at 111 A, no AEC-Q101 documentation | May require additional validation for automotive qualification; lacks documented ISO7637-2 compliance | Consider for industrial 24 V systems where AEC-Q101 is not mandated but thermal performance is critical |
Compared with SMAJ20A-E3/57T and TPSMD20A, the SM5S20A-E3/2D uniquely combines AEC-Q101 qualification, ISO7637-2 validation, and 1.0 °C/W thermal resistance - making it the only option qualified for front-line automotive load dump protection without derating or secondary thermal design.
Availability
SM5S20A-E3/2D is available at Aetrix Electronics and suitable for automotive ECU protection, body control module hardening, and commercial vehicle telematics requiring stable component supply and long-term lifecycle support.
Supply support for SM5S20A-E3/2D 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
Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, MOSFETs, and protection devices with emphasis on high-reliability and automotive-grade performance.
The SM5SxxA series is part of Vishay's PAR® TVS platform, engineered specifically for high-energy automotive load dump protection with enhanced thermal stability and AEC-Q101 compliance.
FAQ
What is the clamping voltage of the SM5S20A-E3/2D at its rated peak pulse current?
The SM5S20A-E3/2D has a maximum clamping voltage (VC) of 32.4 V when subjected to its specified peak pulse current (IPPM) of 111 A using a 10/1000 µs waveform. This value is measured per the conditions defined in the Vishay datasheet document 88382 and reflects the actual voltage seen by downstream circuitry during worst-case surge events - a critical parameter for ensuring compatibility with 3.3 V or 5 V logic supply rails in protected subsystems. The SM5S20A-E3/2D maintains this clamping performance across its full operating temperature range.
Is the SM5S20A-E3/2D suitable for bidirectional transient suppression?
No, the SM5S20A-E3/2D is a unidirectional TVS diode and is not suitable for bidirectional suppression. Its internal structure and polarity marking (anode connected to the heatsink) are optimized for single-polarity overvoltage events such as automotive load dump. For bidirectional applications like data line protection or AC line surge suppression, a dedicated bidirectional TVS like the SMBJ20CA would be required. The SM5S20A-E3/2D datasheet explicitly states "Available in uni-directional polarity only" - confirming this limitation.
What does the "-E3/2D" suffix indicate in SM5S20A-E3/2D?
The "-E3" suffix denotes RoHS-compliant, matte tin-plated leads meeting J-STD-002 and JESD22-B102 solderability standards, while "/2D" specifies packaging in 13-inch plastic tape and reel with 750 units per reel and anode orientation toward the sprocket hole. This ordering code aligns with Vishay's standard delivery format for DO-218AB devices and ensures compatibility with automated SMT placement equipment. The SM5S20A-E3/2D is fully traceable and qualified per AEC-Q101.
How does the SM5S20A-E3/2D compare to the SM5S20 (non-A) variant?
The SM5S20A-E3/2D offers tighter breakdown voltage tolerance (22.2 V to 24.5 V) versus the SM5S20 (22.2 V to 27.1 V), resulting in more predictable clamping onset and reduced risk of premature conduction. It also features lower clamping voltage (32.4 V vs. 35.8 V at same IPPM) and improved thermal resistance due to refined die attachment - both confirmed in Vishay's SM5S10–SM5S36A datasheet revision 14-Sep-11. These enhancements make the SM5S20A-E3/2D preferred for precision-sensitive automotive applications.
Can the SM5S20A-E3/2D be used without a heatsink in PCB layout?
The SM5S20A-E3/2D requires thermal coupling to PCB copper for reliable operation: its metal heatsink (Lead 2) must be soldered to ≥1 cm² of 2 oz copper pour to achieve rated 3600 W surge capability. Without adequate copper area, power derating applies - e.g., at 100 °C case temperature, derated power drops to ~2.5 W. The datasheet specifies RθJC = 1.0 °C/W but assumes direct thermal path to ambient via heatsink; standalone use on minimal copper risks thermal runaway during repeated surges. Always verify layout per Vishay's DO-218AB mounting pad recommendations.
SM5S20A-E3/2D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-218AB
- Series:
- PAR®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-218AB
SM5S20A-E3/2D FAQ
1.How can I place an order for SM5S20A-E3/2D through Aetrix?
Please submit a Request for Quotation (RFQ) for SM5S20A-E3/2D 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 SM5S20A-E3/2D reliable?
The price and inventory of SM5S20A-E3/2D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM5S20A-E3/2D is usually 5 days.
3.What payment methods are accepted for SM5S20A-E3/2D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM5S20A-E3/2D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM5S20A-E3/2D?
SM5S20A-E3/2D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM5S20A-E3/2D 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 SM5S20A-E3/2D?
For technical support, including SM5S20A-E3/2D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM5S20A-E3/2D requirements.
6.How does Aetrix verify that SM5S20A-E3/2D is sourced from the original manufacturer or authorized distributors?
All SM5S20A-E3/2D 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 SM5S20A-E3/2D meets industry standards.
7.What is the process for return or replacement of SM5S20A-E3/2D?
All SM5S20A-E3/2D units undergo pre-shipment inspection (PSI). If there is an issue with SM5S20A-E3/2D, 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 SM5S20A-E3/2D part is unused and in its original packaging.
Return procedure for SM5S20A-E3/2D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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