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Vishay General Semiconductor - Diodes Division SMAJ12CAHM3/I
- Part No.:
- SMAJ12CAHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ12CAHM3/I.pdf
- Description:
- TVS DIODE 12VWM 19.9VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:9,164
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Product details
Overview
SMAJ12CAHM3/I from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed for clamping voltage transients on signal or power lines. It features 12 V stand-off voltage (VWM), 19.9 V maximum clamping voltage at 20.1 A peak pulse current, and 400 W peak pulse power rating with 10/1000 μs waveform - used to protect MOSFETs, ICs, and sensor signal lines in automotive and industrial electronics.
For engineers reviewing the SMAJ12CAHM3/I datasheet, SMAJ12CAHM3/I pinout, SMAJ12CAHM3/I application, or SMAJ12CAHM3/I equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification, halogen-free RoHS compliance, and compatibility with automated SMT placement on PCBs requiring robust ESD and surge immunity per IEC 61000-4-2/4-5.
Technical Context
This device operates as a voltage-clamping protector with symmetrical breakdown behavior in both directions due to its bidirectional construction. It responds within picoseconds to transients, exhibits low incremental surge resistance, and maintains stable clamping performance across -55 °C to +150 °C junction temperature range.
Designed for surface-mount use on standard 0.2" × 0.2" copper pads, the SMAJ12CAHM3/I delivers 400 W peak pulse power below 78 V and derates to 300 W above that threshold. Its glass-passivated junction ensures reliability under repetitive surge stress and meets MSL Level 1 per J-STD-020 at 260 °C peak reflow.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12 V - maximum continuous reverse operating voltage before clamping begins |
| VBR min/max | 13.3 V / 14.7 V at 1 mA - verified breakdown threshold ensuring predictable turn-on |
| VC @ IPPM | 19.9 V at 20.1 A - clamping voltage limits downstream component stress during surge |
| PPPM | 400 W (10/1000 μs) - surge energy handling capacity for lightning and inductive switching events |
| ID @ VWM | 1.0 μA - ultra-low leakage preserves signal integrity in high-impedance circuits |
| TJ max | +150 °C - supports operation in under-hood automotive and industrial environments |
| Package | SMA (DO-214AC) - industry-standard SMT footprint compatible with JEDEC MS-013AC |
Pinout & Package
Two-terminal device in SMA (DO-214AC) package; no polarity marking for bidirectional configuration. Terminals are matte tin-plated, solderable per J-STD-002 and JESD 22-B102, with MSL Level 1 moisture sensitivity rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current entry (either direction) | Acts as cathode during positive half-cycle; enables symmetrical clamping |
| Cathode | Transient current entry (either direction) | Acts as anode during negative half-cycle; eliminates need for orientation during placement |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating signal lines without polarity concerns |
| AEC-Q101 qualified | Validated for automotive powertrain and body electronics applications requiring zero defect reliability |
| Halogen-free & RoHS-compliant | Meets environmental compliance requirements for global OEM supply chains and end-of-life recycling |
| 400 W peak pulse power | Withstands IEC 61000-4-5 Level 4 surges (4 kV line-earth, 2 kV line-line) without degradation |
| Low thermal resistance | RθJL = 30 °C/W enables efficient heat dissipation into PCB copper pads during repeated transients |
Applications
| Automotive Sensor Protection | Industrial PLC I/O Protection |
|---|---|
Use Scenario: Protecting CAN bus transceivers and analog sensor inputs (e.g., pressure, temperature) from load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Voltage clamping element placed directly at connector interface to limit transient amplitude before reaching sensitive ASICs. Use Value: Prevents latch-up or gate oxide damage in automotive microcontrollers by limiting voltage excursion to ≤19.9 V during 20.1 A surge events. | Use Scenario: Safeguarding digital input modules in programmable logic controllers exposed to relay coil flyback and motor drive noise. IC Role / Device Role / Timing Role: Parallel-connected TVS absorbing inductive kickback energy on 24 V DC input channels. Use Value: Maintains functional safety integrity by clamping transients within 1 ns, avoiding false triggering or reset of control logic. |
| Consumer Power Adapter Output | Telecom Line Interface |
Use Scenario: Secondary-side overvoltage suppression in USB-C PD and AC/DC adapters subject to output short-circuit recovery spikes. IC Role / Device Role / Timing Role: Clamp diode across DC output rails to absorb energy from transformer leakage inductance during regulation loop instability. Use Value: Ensures compliance with UL 62368-1 transient immunity requirements while preserving ±5% output regulation tolerance. | Use Scenario: Protecting Ethernet PHY interfaces and DSL line drivers against lightning-induced surges on twisted-pair telecom lines. IC Role / Device Role / Timing Role: Bidirectional shunt protector placed between differential pair and PHY IC, referenced to chassis ground. Use Value: Achieves IEC 61000-4-5 surge immunity up to 4 kV (line-to-ground) without degrading 100 MHz signal integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12CAHE3/I | Same electrical specs; RoHS-compliant but not halogen-free; lacks AEC-Q101 qualification | Suitable for commercial-grade consumer or computing applications only | Select when halogen-free requirement or automotive qualification is not mandated |
| SMBJ12CAHM3/I | Same VWM/VC ratings but in SMB (DO-214AA) package - 25 % larger footprint and higher RθJA (150 °C/W) | Preferred where board space allows and higher thermal margin is needed for sustained surge duty | Choose when PCB layout permits larger pad area and thermal performance outweighs miniaturization goals |
Compared with SMAJ12CAHE3/I and SMBJ12CAHM3/I, the SMAJ12CAHM3/I uniquely combines halogen-free construction, AEC-Q101 qualification, and compact SMA footprint - making it optimal for space-constrained automotive and industrial designs requiring full regulatory compliance.
Availability
SMAJ12CAHM3/I is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial PLC I/O modules, and telecom line protection requiring stable component supply across extended production lifecycles.
Supply support for SMAJ12CAHM3/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 and application-specific performance.
The SMAJ series is engineered for high-energy transient suppression in harsh environments - targeting automotive, industrial, and telecom systems where failure modes must be mitigated without compromising signal fidelity or thermal stability.
FAQ
What does the 'HM3' suffix indicate in SMAJ12CAHM3/I?
The HM3 suffix in SMAJ12CAHM3/I denotes halogen-free, RoHS-compliant construction with AEC-Q101 qualification. It confirms compliance with automotive reliability standards and environmental regulations, distinguishing it from commercial-grade variants like E3 or HE3. This makes SMAJ12CAHM3/I suitable for under-hood and safety-critical applications where material content and long-term stability are strictly controlled.
Is SMAJ12CAHM3/I unidirectional or bidirectional?
SMAJ12CAHM3/I is a bidirectional transient voltage suppressor, as indicated by the 'CA' suffix. It provides symmetrical clamping in both polarities, eliminating polarity marking on the SMA package and enabling use on AC-coupled or floating lines. This differs from unidirectional variants (e.g., SMAJ12A) which require correct cathode orientation and only clamp in reverse bias.
What is the maximum clamping voltage of SMAJ12CAHM3/I and at what current is it specified?
The maximum clamping voltage of SMAJ12CAHM3/I is 19.9 V, measured at a peak pulse current (IPPM) of 20.1 A using a 10/1000 μs waveform. This value is guaranteed per the Vishay datasheet and defines the upper voltage limit imposed on protected circuitry during standardized surge events - critical for ensuring downstream ICs remain within absolute maximum ratings.
Does SMAJ12CAHM3/I meet automotive qualification standards?
Yes, SMAJ12CAHM3/I is AEC-Q101 qualified, as confirmed by Vishay's ordering code structure and documentation. This qualification validates its suitability for automotive applications including engine control units, ADAS sensors, and body electronics, covering stress tests for temperature cycling, humidity, mechanical shock, and accelerated life testing under defined failure criteria.
What is the thermal resistance specification for SMAJ12CAHM3/I?
SMAJ12CAHM3/I has a typical junction-to-lead thermal resistance (RθJL) of 30 °C/W and junction-to-ambient resistance (RθJA) of 120 °C/W when mounted on minimum recommended 0.2" × 0.2" copper pads. These values determine how effectively heat from surge events dissipates into the PCB, directly influencing safe repetition rate and long-term reliability under cyclic transient loading.
SMAJ12CAHM3/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:
- Discontinued at Digi-Key
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- 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)
SMAJ12CAHM3/I FAQ
1.How can I place an order for SMAJ12CAHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ12CAHM3/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 SMAJ12CAHM3/I reliable?
The price and inventory of SMAJ12CAHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ12CAHM3/I is usually 5 days.
3.What payment methods are accepted for SMAJ12CAHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ12CAHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ12CAHM3/I?
SMAJ12CAHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ12CAHM3/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 SMAJ12CAHM3/I?
For technical support, including SMAJ12CAHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ12CAHM3/I requirements.
6.How does Aetrix verify that SMAJ12CAHM3/I is sourced from the original manufacturer or authorized distributors?
All SMAJ12CAHM3/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 SMAJ12CAHM3/I meets industry standards.
7.What is the process for return or replacement of SMAJ12CAHM3/I?
All SMAJ12CAHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ12CAHM3/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 SMAJ12CAHM3/I part is unused and in its original packaging.
Return procedure for SMAJ12CAHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ12CAHM3/I Tags
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