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Vishay General Semiconductor - Diodes Division SMAJ20AHE3_A/I
- Part No.:
- SMAJ20AHE3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ20AHE3_A/I.pdf
- Description:
- TVS DIODE 20VWM 32.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,773
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Product details
Overview
SMAJ20AHE3_A/I from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed for robust overvoltage protection of sensitive electronics. It features a 20 V standoff voltage (VWM), 22.2–24.5 V breakdown voltage (VBR) at 1 mA, 32.4 V maximum clamping voltage (VC) at 12.3 A peak pulse current (IPPM), and 400 W peak pulse power rating with 10/1000 μs waveform - deployed on power rails and signal lines in automotive ECUs and industrial sensor interfaces.
For engineers reviewing the SMAJ20AHE3_A/I datasheet, SMAJ20AHE3_A/I pinout, SMAJ20AHE3_A/I application, or SMAJ20AHE3_A/I equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, thermal resistance (RθJA = 120 °C/W), clamping performance under surge conditions, and direct alternatives for automotive-grade TVS selection.
Technical Context
This unidirectional TVS operates as a voltage-clamping device that remains high-impedance below VWM (20 V) and rapidly transitions to low-impedance conduction above VBR (min. 22.2 V) to shunt transient energy. Its glass-passivated junction ensures stable leakage (<1.0 μA at VWM) and fast response time (<1.0 ps), critical for protecting MOSFET gates and microcontroller I/O pins against ESD and load-switching spikes.
The device is rated for 40 A non-repetitive forward surge current (IFSM, 8.3 ms half-sine), supports operating junction temperatures from –55 °C to +150 °C, and meets MSL Level 1 per J-STD-020 with 260 °C reflow peak. Its SMA package enables automated placement and provides 30 °C/W junction-to-lead thermal resistance for localized heat dissipation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20 V - Maximum continuous reverse operating voltage before clamping initiates; defines safe DC/AC rail margin. |
| VBR (min/max) | 22.2 V / 24.5 V at 1 mA - Confirmed breakdown threshold range; ensures reliable turn-on during transients without premature conduction. |
| VC @ IPPM | 32.4 V at 12.3 A - Clamped voltage during 10/1000 μs surge; determines protected circuit's maximum stress level. |
| PPPM | 400 W - Peak pulse power handling capability; validates protection against ISO 7637-2 Pulse 1/2a/5a and IEC 61000-4-5 surges. |
| ID @ VWM | ≤1.0 μA - Reverse leakage current at rated standoff; ensures negligible standby power loss in battery-powered systems. |
| TJ max. | +150 °C - Maximum junction temperature; supports under-hood automotive deployment and industrial ambient extremes. |
| RθJA | 120 °C/W - Junction-to-ambient thermal resistance on standard 0.2" × 0.2" copper pads; informs PCB thermal layout requirements. |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, molded plastic case with matte tin-plated leads. Cathode indicated by band; anode is unmarked end.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Transient current sink | Connected to protected line (e.g., CAN_H, VDD_IO); conducts surge current to ground when voltage exceeds VBR. |
| Anode (unbanded end) | Reference node | Typically tied to system ground or low-impedance return path; completes clamping loop during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control, ADAS sensors, and infotainment power rails. |
| 400 W peak pulse power (10/1000 μs) | Withstands repetitive ISO 7637-2 load-dump surges up to 300 W above 78 V and full 400 W below. |
| Glass passivated junction | Ensures long-term reliability and stable VBR drift <±5 % over lifetime under thermal cycling and humidity stress. |
| MSL Level 1 (260 °C peak) | Compatible with standard lead-free reflow profiles without preconditioning or dry-pack requirements. |
| Low incremental surge resistance | Minimizes VC overshoot during fast-rising transients (e.g., ESD >15 kV contact), improving clamping fidelity. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Signal Line Protection |
|---|---|
|
Use Scenario: Protecting 12 V battery-fed MCU power inputs in body control modules against load dump and jump-start surges. IC Role / Device Role / Timing Role: Unidirectional clamping TVS placed between VDD and GND, activated within picoseconds of overvoltage onset. Use Value: Limits voltage to ≤32.4 V during 12.3 A transients, preventing damage to 3.3 V/5 V regulators and logic ICs downstream. |
Use Scenario: Safeguarding analog output lines (e.g., 4–20 mA current loop) of pressure sensors in factory automation PLCs. IC Role / Device Role / Timing Role: Bidirectional-capable unidirectional TVS (cathode to signal, anode to ground) suppressing ±1 kV EFT bursts. Use Value: Maintains signal integrity with <1.0 μA leakage at 20 V, enabling sub-μA precision measurement while clamping to 32.4 V. |
| Consumer Device USB Port Protection | Telecom Equipment DC Power Input |
|
Use Scenario: Shielding USB VBUS lines in portable medical monitors from hot-plug transients and ESD events. IC Role / Device Role / Timing Role: Standoff-rated TVS on VBUS rail, conducting only during >22.2 V excursions to preserve normal 5 V operation. Use Value: Achieves <15 ns response time and clamps 8 kV contact ESD to ≤32.4 V, meeting IEC 61000-4-2 Level 4. |
Use Scenario: Front-end surge suppression on -48 V DC telecom power feeds exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Unidirectional TVS configured cathode-to-rail for negative supply protection, leveraging same VWM/VBR symmetry. Use Value: Handles 400 W pulses without degradation, enabling compliance with GR-1089-CORE Section 4.5.2.2 AC/DC power port immunity. |
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-E3/61 | Same electrical specs and SMA package; RoHS-compliant commercial grade without AEC-Q101 qualification. | Lacks automotive qualification; suitable for industrial/commercial designs where AEC-Q101 is not mandated. | Select when cost sensitivity outweighs automotive qualification requirements and lifecycle assurance is managed externally. |
| SMAJ20AHM3_A/I | Identical VWM, VBR, VC, and PPPM; halogen-free, RoHS-compliant, and AEC-Q101 qualified - differs only in lead finish chemistry. | No functional difference; used where halogen-free BOM compliance is required (e.g., EU public infrastructure tenders). | Choose when halogen-free material declaration (IEC 61249-2-21) is mandatory, with no trade-off in performance or qualification. |
Compared with SMAJ20AHE3_A/I, SMAJ20A-E3/61 omits AEC-Q101 validation and is lower-cost for non-automotive use, while SMAJ20AHM3_A/I retains full qualification but adds halogen-free compliance - both share identical clamping behavior, thermal limits, and footprint, enabling drop-in substitution where material or qualification scope permits.
Availability
SMAJ20AHE3_A/I is available at Aetrix Electronics and suitable for automotive electronic control units, industrial sensor interfaces, and telecom power input stages requiring stable component supply with AEC-Q101 assurance and long-term production continuity.
Supply support for SMAJ20AHE3_A/I 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 reliability, power efficiency, and automotive-grade qualification.
The SMAJ series was engineered specifically for high-energy transient suppression in harsh environments - targeting ISO 7637-2, IEC 61000-4-5, and AEC-Q101-compliant applications across automotive, industrial, and telecom sectors.
FAQ
What is the clamping voltage of SMAJ20AHE3_A/I at its rated peak pulse current?
The SMAJ20AHE3_A/I has a maximum clamping voltage (VC) of 32.4 V at its rated peak pulse current (IPPM) of 12.3 A, measured using the standardized 10/1000 μs double-exponential surge waveform. This value defines the upper voltage limit imposed on protected circuitry during transient events and is confirmed per Vishay Document Number 88390, page 2. The SMAJ20AHE3_A/I maintains this clamping performance across its full operating temperature range (–55 °C to +150 °C).
Is SMAJ20AHE3_A/I qualified for automotive applications?
Yes, SMAJ20AHE3_A/I is AEC-Q101 qualified, as explicitly stated in the Vishay datasheet (Document Number 88390, page 1, "FEATURES" section and page 3, "ORDERING INFORMATION" footnote 1). This qualification confirms its suitability for automotive powertrain, chassis, and body electronics where reliability under thermal cycling, mechanical shock, and extended temperature operation is mandatory. The "HE3" suffix denotes RoHS-compliant and AEC-Q101-qualified construction.
What is the standoff voltage (VWM) and why is it critical for SMAJ20AHE3_A/I placement?
The standoff voltage (VWM) of SMAJ20AHE3_A/I is 20 V - the maximum continuous reverse voltage it can block without significant conduction. This parameter is critical because it must exceed the normal operating voltage of the protected line (e.g., 12 V automotive rail or 24 V industrial bus) to prevent leakage or thermal runaway. Placing SMAJ20AHE3_A/I with VWM = 20 V on a 24 V line would cause excessive ID and potential failure; correct application requires VWM ≥ 1.2× nominal rail voltage.
How does the thermal resistance of SMAJ20AHE3_A/I affect PCB layout?
SMAJ20AHE3_A/I has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W when mounted on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. To maintain TJ ≤ 150 °C under worst-case 3.3 W steady-state dissipation, PCB layout must provide adequate copper area and thermal vias - undersized pads increase RθJA, risking thermal runaway during repetitive surges. The SMAJ20AHE3_A/I datasheet specifies minimum pad dimensions on page 5 to ensure rated thermal performance.
Can SMAJ20AHE3_A/I be used in bidirectional protection circuits?
No, SMAJ20AHE3_A/I is a unidirectional TVS diode, indicated by the "A" suffix and cathode band marking. It conducts only when the cathode is positive relative to the anode. For bidirectional protection (e.g., AC lines or differential buses like RS-485), the "CA" variant - SMAJ20CAHE3_A/I - must be used. Using SMAJ20AHE3_A/I in bidirectional configurations risks failure during negative-going transients, as it lacks reverse breakdown capability.
SMAJ20AHE3_A/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AC, SMA
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- 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):
- 12.3A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ20AHE3_A/I FAQ
1.How can I place an order for SMAJ20AHE3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ20AHE3_A/I 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 SMAJ20AHE3_A/I reliable?
The price and inventory of SMAJ20AHE3_A/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ20AHE3_A/I is usually 5 days.
3.What payment methods are accepted for SMAJ20AHE3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ20AHE3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ20AHE3_A/I?
SMAJ20AHE3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ20AHE3_A/I 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 SMAJ20AHE3_A/I?
For technical support, including SMAJ20AHE3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ20AHE3_A/I requirements.
6.How does Aetrix verify that SMAJ20AHE3_A/I is sourced from the original manufacturer or authorized distributors?
All SMAJ20AHE3_A/I 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 SMAJ20AHE3_A/I meets industry standards.
7.What is the process for return or replacement of SMAJ20AHE3_A/I?
All SMAJ20AHE3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ20AHE3_A/I, 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 SMAJ20AHE3_A/I part is unused and in its original packaging.
Return procedure for SMAJ20AHE3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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