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Vishay General Semiconductor - Diodes Division SMAJ12AHM3/H
- Part No.:
- SMAJ12AHM3/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ12AHM3/H.pdf
- Description:
- TVS DIODE 12VWM 19.9VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:6,011
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Product details
Overview
SMAJ12AHM3/H from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed for clamping fast-rising 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 power rails.
For engineers reviewing the SMAJ12AHM3/H datasheet, SMAJ12AHM3/H pinout, SMAJ12AHM3/H application, or SMAJ12AHM3/H equivalent, this page delivers verified electrical specs, thermal behavior, AEC-Q101 qualification status, JEDEC-compliant packaging details, and real-world protection use cases - all aligned to Vishay's 09-Jan-2024 revision of document 88390.
Technical Context
This TVS diode operates as a unidirectional clamping device with cathode-band polarity marking, optimized for low-inductance PCB layouts using 0.2" × 0.2" copper pads per terminal. Its glass-passivated junction enables fast response time (<1 ns) and low incremental surge resistance, critical for suppressing ESD and inductive switching spikes.
The SMAJ12AHM3/H is halogen-free and RoHS-compliant (HM3 suffix), qualified to AEC-Q101 for automotive applications, and rated for operation from –55 °C to +150 °C junction temperature. It meets UL 497B recognition (QVGQ2) and J-STD-020 MSL Level 1 reflow profile (260 °C peak).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12 V - maximum continuous reverse operating voltage before clamping begins; defines safe DC/AC working margin on protected line |
| VBR min/max | 13.3 V / 14.7 V at 1 mA - guaranteed breakdown threshold range; ensures predictable turn-on during overvoltage events |
| VC @ IPPM | 19.9 V at 20.1 A - clamped voltage under 10/1000 μs surge; determines worst-case stress on downstream components |
| PPPM | 400 W - peak pulse power handling with standard 10/1000 μs waveform; supports robust protection against IEC 61000-4-5 surges |
| ID @ VWM | 1.0 μA - maximum reverse leakage at 12 V; negligible power loss and minimal impact on high-impedance circuits |
| TJ max | +150 °C - maximum junction temperature; enables reliable operation in under-hood automotive and industrial environments |
| RθJA | 120 °C/W - thermal resistance junction-to-ambient on standard pad layout; informs derating requirements above 25 °C ambient |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, halogen-free, matte tin-plated leads solderable per J-STD-002 and JESD 22-B102. Polarity indicated by cathode band on unidirectional devices.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction path (unidirectional) | Connected to lower-potential side of protected line; conducts only during forward-biased surge conditions |
| Cathode | Clamping node (marked with band) | Connected to higher-potential side; initiates avalanche breakdown when reverse voltage exceeds VBR |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per stress test plan |
| 400 W peak pulse power | Handles repetitive 10/1000 μs transients up to 0.01% duty cycle without degradation - sufficient for ISO 7637-2 Pulse 1/2a/2b |
| Low clamping ratio (VC/VBR ≈ 1.42) | Minimizes overvoltage overshoot during clamping - protects 12 V logic and gate drivers with tight voltage margins |
| MSL Level 1 moisture sensitivity | Allows unlimited floor life and standard reflow without baking - simplifies SMT manufacturing flow |
| UL 497B recognized (QVGQ2) | Meets safety standards for telecom and industrial signal-line protectors - reduces certification burden for end equipment |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Suppressing load-dump and jump-start transients on 12 V battery-fed ECUs and body control modules. IC Role / Device Role / Timing Role: Unidirectional clamping TVS placed between battery rail and input filter capacitor. Use Value: Limits voltage to ≤19.9 V during 35 V/100 ms load dump, preventing damage to 24 V-rated regulators and CAN transceivers. | Use Scenario: Protecting analog outputs of pressure/temperature sensors connected to PLC analog inputs. IC Role / Device Role / Timing Role: Standoff-clamp TVS on 4–20 mA loop supply line, upstream of series resistor and op-amp input stage. Use Value: Clamps induced lightning surges to <20 V, preserving 24 V input-stage headroom and avoiding ADC saturation or latch-up. |
| Consumer Power Adapter Input Stage | Telecom Line Card Surge Protection |
Use Scenario: Safeguarding AC-DC adapter primary-side rectifier and controller ICs against mains-borne surges. IC Role / Device Role / Timing Role: Secondary-side TVS across DC output rail (12 V), coordinated with primary MOV and Y-cap filtering. Use Value: Absorbs residual 400 W surges after primary suppression, ensuring regulated output stays within ±10% tolerance during EN 61000-4-5 testing. | Use Scenario: Shielding Ethernet PHY and PoE controller pins from ESD and induced surges on RJ45 interface traces. IC Role / Device Role / Timing Role: Discrete TVS on each data pair (e.g., TX+/TX−), placed adjacent to connector with short trace routing. Use Value: Achieves <1 ns response and <20 V clamping, meeting IEC 61000-4-2 Level 4 (15 kV air/8 kV contact) without signal integrity degradation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12AHE3/H | RoHS-compliant but not halogen-free; same VWM, VBR, VC, and PPPM ratings | Lacks halogen-free compliance required for some automotive Tier 1 specifications | Select SMAJ12AHM3/H when halogen-free material declaration is mandatory per OEM PPAP |
| SMBJ12A-H | Same electrical specs but in larger SMB (DO-214AA) package; RθJA = 85 °C/W vs. 120 °C/W | Higher thermal dissipation capability allows higher sustained surge repetition rates | Choose SMBJ12A-H where board space permits and thermal derating margin is critical for high-duty-cycle environments |
Compared with SMAJ12AHE3/H and SMBJ12A-H, the SMAJ12AHM3/H uniquely combines AEC-Q101 qualification, halogen-free construction, and compact SMA footprint - making it optimal for space-constrained, automotive-qualified 12 V rail protection where material compliance and reliability are jointly mandated.
Availability
SMAJ12AHM3/H is available at Aetrix Electronics and suitable for automotive electronics, industrial sensor systems, and consumer power adapter designs requiring stable component supply, long-term lifecycle support, and full traceability.
Supply support for SMAJ12AHM3/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, TVS, MOSFETs, and optoelectronics with emphasis on reliability, efficiency, and application-specific optimization.
The SMAJ series is engineered for high-energy transient suppression in harsh environments - targeting automotive, industrial, and telecom applications where robustness, AEC-Q101 compliance, and standardized mounting are essential.
FAQ
What is the clamping voltage of the SMAJ12AHM3/H under a 10/1000 μs surge?
The SMAJ12AHM3/H has a maximum clamping voltage (VC) of 19.9 V at 20.1 A peak pulse current (IPPM) with a 10/1000 μs waveform. This value is measured per Figure 1 in Vishay document 88390 and reflects worst-case voltage seen by downstream circuitry during standardized surge events - critical for verifying margin against 24 V-rated ICs and gate drivers in the protected system.
Is the SMAJ12AHM3/H qualified for automotive applications?
Yes, the SMAJ12AHM3/H carries AEC-Q101 qualification (denoted by HM3 suffix), validated across temperature cycling, high-temperature reverse bias (HTRB), and ESD tests per the AEC stress test plan. It is explicitly listed in Vishay's ordering information table with "_H" package code and "HM3" grade, confirming its suitability for under-hood and chassis-mounted automotive electronics.
How does the SMAJ12AHM3/H differ from the SMAJ12A-E3/H variant?
The SMAJ12AHM3/H is halogen-free and RoHS-compliant, whereas SMAJ12A-E3/H is RoHS-compliant but contains halogens. Both share identical electrical parameters (VWM = 12 V, VBR = 13.3–14.7 V, VC = 19.9 V), package (SMA), and AEC-Q101 qualification. The HM3 suffix ensures compliance with automotive OEM halogen restrictions, such as those in GM GP10 or Ford WSS-M99P9999-A1.
What is the thermal resistance of the SMAJ12AHM3/H on standard PCB layout?
The SMAJ12AHM3/H has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W when mounted on minimum recommended 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. This value assumes no additional heatsinking and governs derating above 25 °C ambient - for example, at 85 °C ambient, maximum allowable power drops to ~1.8 W based on TJ max = 150 °C.
Does the SMAJ12AHM3/H meet UL safety standards?
Yes, the SMAJ12AHM3/H is Underwriters Laboratory (UL) recognized under standard UL 497B for protectors, with file number E136766. This applies to both unidirectional and bidirectional variants in the SMAJ family and confirms suitability for use in telecom, industrial, and consumer equipment requiring third-party safety certification for transient protection circuits.
SMAJ12AHM3/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:
- Discontinued at Digi-Key
- 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:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ12AHM3/H FAQ
1.How can I place an order for SMAJ12AHM3/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ12AHM3/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 SMAJ12AHM3/H reliable?
The price and inventory of SMAJ12AHM3/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ12AHM3/H is usually 5 days.
3.What payment methods are accepted for SMAJ12AHM3/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ12AHM3/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ12AHM3/H?
SMAJ12AHM3/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ12AHM3/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 SMAJ12AHM3/H?
For technical support, including SMAJ12AHM3/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ12AHM3/H requirements.
6.How does Aetrix verify that SMAJ12AHM3/H is sourced from the original manufacturer or authorized distributors?
All SMAJ12AHM3/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 SMAJ12AHM3/H meets industry standards.
7.What is the process for return or replacement of SMAJ12AHM3/H?
All SMAJ12AHM3/H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ12AHM3/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 SMAJ12AHM3/H part is unused and in its original packaging.
Return procedure for SMAJ12AHM3/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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