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Vishay General Semiconductor - Diodes Division SMAJ12AHE3_A/H
- Part No.:
- SMAJ12AHE3_A/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ12AHE3_A/H.pdf
- Description:
- TVS DIODE 12VWM 19.9VC DO214AC
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
SMAJ12AHE3_A/H from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMA (DO-214AC) package, designed for clamping voltage transients on power and signal lines. It features a 12 V stand-off voltage (VWM), 13.3–14.7 V breakdown voltage (VBR) at 1 mA, 19.9 V maximum clamping voltage (VC) at 20.1 A peak pulse current (IPPM), and 400 W peak pulse power rating with 10/1000 μs waveform - used to protect MOSFETs, ICs, and sensor interfaces in automotive and industrial control systems.
For engineers reviewing the SMAJ12AHE3_A/H datasheet, SMAJ12AHE3_A/H pinout, SMAJ12AHE3_A/H application, or SMAJ12AHE3_A/H equivalent, key selection criteria include unidirectional polarity, AEC-Q101 qualification, 150 °C max junction temperature, low incremental surge resistance, and compatibility with automated SMT placement on 0.2" × 0.2" copper pads.
Technical Context
This TVS diode operates as a fast-acting shunt protector: under normal conditions it presents high impedance (>1 MΩ leakage at 12 V), then avalanches within <1 ns when transient voltage exceeds VBR to clamp the line at ≤19.9 V. Its glass-passivated junction ensures stable breakdown characteristics and long-term reliability under repetitive surge stress.
The device is rated for 40 A non-repetitive forward surge current (IFSM, 8.3 ms half-sine), supports continuous power dissipation of 3.3 W at 50 °C ambient, and exhibits a positive temperature coefficient of VBR (+0.083 %/°C), enabling predictable derating across -55 °C to +150 °C operating range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12 V - maximum continuous reverse working voltage before significant leakage; defines safe operating margin below clamping threshold |
| VBR min/max | 13.3 V / 14.7 V at 1 mA - guaranteed avalanche initiation range; ensures consistent turn-on behavior across production lots |
| VC @ IPPM | 19.9 V at 20.1 A - clamped voltage during 10/1000 μs surge; determines protected circuit's maximum overvoltage exposure |
| PPPM | 400 W - peak pulse power handling capability; enables protection against IEC 61000-4-5 Level 4 surges (4 kV/2 Ω) |
| ID @ VWM | 1.0 μA - reverse leakage current at 12 V; negligible loading on 3.3 V or 5 V logic/sensor rails |
| TJ max | +150 °C - maximum junction temperature; supports under-hood automotive and high-ambient industrial environments |
| Package | SMA (DO-214AC) - industry-standard surface-mount outline with 0.208" x 0.157" footprint and matte tin-plated leads compliant with J-STD-002 |
Pinout & Package
Package: SMA (DO-214AC), single-axis molded case with cathode band marking. Dimensions: 4.93 mm × 3.99 mm × 2.29 mm (L × W × H); terminals are matte tin-plated, solderable per J-STD-002 and JESD 22-B102.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or lowest potential node; completes conduction path during transient clamping |
| Cathode | High-side input terminal | Connected to protected line (e.g., 12 V rail or sensor output); marked by black band per JEDEC DO-214AC standard |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, humidity bias, and mechanical shock per AEC specification |
| 400 W peak pulse power | Withstands 10/1000 μs surges up to 20.1 A without degradation - sufficient for ISO 7637-2 Pulse 1/2a/3a and IEC 61000-4-5 combinations |
| Glass passivated junction | Eliminates surface contamination sensitivity and improves long-term stability of VBR and leakage performance |
| MSL Level 1 | Moisture sensitivity level 1 per J-STD-020 - no floor life limitation or bake requirement prior to reflow |
| Low profile & SMT-compatible | Height ≤2.29 mm and lead-free RoHS-compliant (HE3 suffix) - compatible with high-speed pick-and-place and standard reflow profiles |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
|
Use Scenario: 12 V battery-supplied ECUs exposed to load dump (ISO 7637-2 Pulse 5a) and alternator switching transients. IC Role / Device Role / Timing Role: Unidirectional shunt TVS placed between power rail and chassis ground to clamp surges before reaching downstream regulators and microcontrollers. Use Value: Limits rail overvoltage to ≤19.9 V during 20.1 A transients, preventing latch-up or gate oxide damage in 3.3 V/5 V logic devices. |
Use Scenario: Analog output lines (e.g., 4–20 mA current loop or 0–5 V voltage output) from pressure/temperature sensors in factory automation. IC Role / Device Role / Timing Role: Point-of-entry protection on sensor PCB, mounted directly at connector pins to suppress ESD (IEC 61000-4-2) and cable-induced surges. Use Value: Sub-1 ns response and <1 μA leakage preserve signal integrity and accuracy while surviving ±15 kV contact ESD events. |
| Consumer Power Adapter Input Protection | Telecom Line Card Surge Protection |
|
Use Scenario: Secondary-side DC output (e.g., 12 V/19 V) of wall adapters subject to lightning-induced surges via shared AC mains. IC Role / Device Role / Timing Role: Final-stage clamping device after primary-side isolation, protecting USB-PD controllers and buck converters. Use Value: 400 W rating and 120 °C/W RθJA enable self-limiting thermal behavior without heatsinking in compact adapter enclosures. |
Use Scenario: Ethernet or RS-485 data lines in telecom base station line cards exposed to induced surges from nearby lightning strikes. IC Role / Device Role / Timing Role: Low-capacitance (<100 pF) unidirectional TVS on each signal line, referenced to local ground plane. Use Value: Clamps common-mode transients to <20 V while maintaining signal rise time integrity due to minimal junction capacitance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12A-E3/61 | Commercial-grade (non-AEC-Q101), same electrical specs and SMA package | Lacks automotive qualification; suitable for consumer/industrial designs without AEC compliance requirements | Select when cost sensitivity outweighs automotive reliability validation needs |
| SMBJ12AHE3_A/H | Same AEC-Q101 qualification but in larger SMB (DO-214AA) package; 600 W PPPM rating | Higher surge capacity and lower RθJA (80 °C/W) - preferred for high-energy transients or thermally constrained layouts | Choose when system-level surge testing exceeds 400 W or board space allows larger footprint |
Compared with SMAJ12AHE3_A/H, SMAJ12A-E3/61 offers identical protection performance at lower cost but no automotive qualification, while SMBJ12AHE3_A/H provides higher surge margin and better thermal performance in a larger package - enabling trade-offs between footprint, reliability tier, and energy handling.
Availability
SMAJ12AHE3_A/H is available at Aetrix Electronics and suitable for automotive ECUs, industrial sensor modules, consumer power adapters, and telecom line cards requiring stable component supply with AEC-Q101 assurance and full traceability.
Supply support for SMAJ12AHE3_A/H 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 solutions.
The SMAJ series is engineered for robust transient suppression in harsh environments, targeting automotive power distribution, industrial control I/O, and telecom infrastructure where repeatable clamping and AEC-Q101 validation are mandatory.
FAQ
What is the clamping voltage of SMAJ12AHE3_A/H at its rated peak pulse current?
The SMAJ12AHE3_A/H has a maximum clamping voltage (VC) of 19.9 V when subjected to its rated peak pulse current (IPPM) of 20.1 A with a 10/1000 μs waveform. This value is measured per standard test conditions in the Vishay datasheet (Document Number: 88390) and defines the upper voltage limit imposed on protected circuits during surge events. Maintaining VC below 20 V ensures compatibility with 12 V nominal systems and safeguards downstream 3.3 V or 5 V logic components.
Is SMAJ12AHE3_A/H suitable for automotive applications?
Yes, SMAJ12AHE3_A/H is AEC-Q101 qualified, as confirmed by Vishay's ordering code suffix "HE3" and documentation note (page 3). It undergoes rigorous stress testing including temperature cycling, high-temperature reverse bias, and mechanical shock, making it suitable for under-hood and body-control module applications. The device's 150 °C max junction temperature and stable VBR temperature coefficient (+0.083 %/°C) further support automotive thermal requirements.
What is the difference between SMAJ12AHE3_A/H and SMAJ12A-E3/61?
SMAJ12AHE3_A/H and SMAJ12A-E3/61 share identical electrical specifications (VWM = 12 V, VC = 19.9 V, PPPM = 400 W) and SMA package, but differ in qualification: SMAJ12AHE3_A/H is AEC-Q101 qualified and intended for automotive use, whereas SMAJ12A-E3/61 is commercial-grade only. Both are RoHS-compliant, but only the HE3 version meets automotive reliability standards required for OEM production.
Does SMAJ12AHE3_A/H have polarity marking, and how is it identified?
Yes, SMAJ12AHE3_A/H is unidirectional and features a cathode band - a visible black marking near one end of the SMA (DO-214AC) package. Per JEDEC standard, the banded end is the cathode and must be connected to the higher-potential side (e.g., 12 V rail), while the anode connects to ground or return. This polarity is critical: reverse connection renders the device ineffective for overvoltage protection.
What is the thermal resistance and power derating behavior of SMAJ12AHE3_A/H?
SMAJ12AHE3_A/H has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W when mounted on 0.2" × 0.2" copper pads. Its continuous power dissipation (PD) is rated at 3.3 W at TA = 50 °C and derates linearly above that temperature - dropping to ~1.7 W at 100 °C ambient. This derating curve (Fig. 2 in datasheet 88390) ensures safe operation within the -55 °C to +150 °C junction temperature range under sustained power stress.
SMAJ12AHE3_A/H 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):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 19.9V
- Current - Peak Pulse (10/1000µs):
- 20.1A
- 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)
SMAJ12AHE3_A/H FAQ
1.How can I place an order for SMAJ12AHE3_A/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ12AHE3_A/H 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 SMAJ12AHE3_A/H reliable?
The price and inventory of SMAJ12AHE3_A/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ12AHE3_A/H is usually 5 days.
3.What payment methods are accepted for SMAJ12AHE3_A/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ12AHE3_A/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ12AHE3_A/H?
SMAJ12AHE3_A/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ12AHE3_A/H 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 SMAJ12AHE3_A/H?
For technical support, including SMAJ12AHE3_A/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ12AHE3_A/H requirements.
6.How does Aetrix verify that SMAJ12AHE3_A/H is sourced from the original manufacturer or authorized distributors?
All SMAJ12AHE3_A/H 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 SMAJ12AHE3_A/H meets industry standards.
7.What is the process for return or replacement of SMAJ12AHE3_A/H?
All SMAJ12AHE3_A/H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ12AHE3_A/H, 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 SMAJ12AHE3_A/H part is unused and in its original packaging.
Return procedure for SMAJ12AHE3_A/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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