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Vishay General Semiconductor - Diodes Division SMAJ12CAHM3_A/H
- Part No.:
- SMAJ12CAHM3_A/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ12CAHM3_A/H.pdf
- Description:
- TVS DIODE 12VWM 19.9VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:8,190
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Product details
Overview
SMAJ12CAHM3_A/H from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed for clamping voltage transients on signal and power 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, 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 SMAJ12CAHM3_A/H datasheet, SMAJ12CAHM3_A/H pinout, SMAJ12CAHM3_A/H application, or SMAJ12CAHM3_A/H equivalent, this device serves as a halogen-free, AEC-Q101-qualified TVS for bidirectional overvoltage protection where low-profile surface-mount placement, fast response (<1 ns), and stable clamping under repetitive surge conditions are required.
Technical Context
This bidirectional TVS operates symmetrically across both polarities, with identical electrical characteristics in forward and reverse directions. Its glass-passivated junction ensures stable breakdown behavior and low leakage (<1.0 μA at VWM), while the SMA package supports automated placement and meets MSL level 1 reflow requirements (260 °C peak).
The device delivers 400 W peak pulse power up to 78 V, derating to 300 W above that threshold. Thermal resistance is 120 °C/W (junction-to-ambient) and 30 °C/W (junction-to-lead), enabling reliable operation up to +150 °C junction temperature under defined PCB pad layout (0.2" × 0.2" copper per terminal).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12 V - Maximum continuous reverse working voltage before significant conduction begins; defines safe operating margin below clamping threshold. |
| VBR min/max | 13.3 V / 14.7 V at 1 mA - Confirmed breakdown range ensuring predictable turn-on during transients without premature leakage. |
| VC @ IPPM | 19.9 V at 20.1 A - Clamped voltage seen by protected circuit during 10/1000 μs surge; limits stress on downstream components. |
| PPPM | 400 W - Peak pulse power handling capability with standard 10/1000 μs waveform; validates robustness against common ESD and load-switching events. |
| IFSM | 40 A - Non-repetitive forward surge current rating (8.3 ms half-sine); supports unidirectional surge tolerance if used in asymmetric configurations. |
| TJ max | +150 °C - Maximum junction temperature; enables use in under-hood automotive and high-temperature industrial environments. |
| Package | SMA (DO-214AC) - Low-profile surface-mount outline with 2.54 mm lead pitch; compatible with standard SMT assembly and IPC-7351B land patterns. |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with matte tin-plated leads, UL 94 V-0 rated, MSL Level 1 compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry point in forward bias | Terminal where conventional current flows into device during positive transient; no marking on bidirectional types. |
| Cathode | Current exit point in forward bias | Terminal where conventional current exits during positive transient; not marked on SMAJ12CAHM3_A/H due to bidirectional symmetry. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Identical VBR, VC, and IPPM performance in both polarities - eliminates polarity concerns in AC-coupled or floating signal line protection. |
| AEC-Q101 qualification | Validated for automotive-grade reliability including temperature cycling, HTRB, and surge endurance - suitable for engine control, body electronics, and ADAS sensor interfaces. |
| Halogen-free & RoHS-compliant | HM3 suffix denotes halogen-free molding compound and lead finish - meets EU ELV and China RoHS environmental compliance requirements. |
| Fast response time | <1 ns typical response - ensures clamping activation before transient energy damages sensitive CMOS inputs or gate oxides. |
| Low incremental surge resistance | Minimizes VC overshoot during high-di/dt events - improves protection margin for fast-rising transients like ISO 7637-2 Pulse 1/2a/5a. |
Applications
| Automotive Power Line Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Protecting LIN bus or 12 V power rails in body control modules from load dump and inductive switching spikes. IC Role / Device Role / Timing Role: Bidirectional voltage clamp placed between power rail and ground, responding within nanoseconds to suppress transients exceeding 12 V. Use Value: Limits rail voltage to ≤19.9 V during 20.1 A surges, preventing latch-up or destruction of microcontrollers and CAN/LIN transceivers. | Use Scenario: Shielding analog output lines (e.g., 4–20 mA current loop) of pressure or temperature sensors from ESD and field wiring faults. IC Role / Device Role / Timing Role: Low-capacitance TVS connected across signal and return, providing symmetrical clamping without distorting DC signal integrity. Use Value: Maintains signal accuracy with <1.0 μA leakage at 12 V, while clamping ±19.9 V transients to preserve sensor amplifier input stage reliability. |
| Consumer Device USB Port Protection | Telecom Equipment DC Power Input Protection |
Use Scenario: Safeguarding USB 2.0 data lines and VBUS against human-body-model (HBM) ESD and hot-plug transients in portable devices. IC Role / Device Role / Timing Role: Bidirectional TVS placed on D+ and D− lines, leveraging symmetric clamping to handle differential and common-mode surges. Use Value: Delivers sub-20 V clamping with minimal capacitance impact - preserves signal rise/fall times and USB 480 Mbps eye diagram integrity. | Use Scenario: Guarding primary DC input (e.g., 12–48 V) of base station power supplies against lightning-induced surges and grid switching noise. IC Role / Device Role / Timing Role: Front-end clamping device mounted before bulk capacitors and DC-DC converters, absorbing multi-kW surge energy in coordination with MOVs. Use Value: Withstands 400 W pulses and 40 A non-repetitive surges, extending system uptime and reducing field failure rates in outdoor telecom cabinets. |
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_A/H | RoHS-compliant but not halogen-free; same electrical specs and AEC-Q101 qualification. | Acceptable where halogen content is unrestricted; slightly lower environmental compliance tier. | Select when cost sensitivity outweighs halogen-free requirement and AEC-Q101 qualification is mandatory. |
| SMBJ12CAHM3_A/H | Same VWM/VC but higher PPPM (600 W); larger SMB (DO-214AA) package with 3.5 mm lead pitch. | Better suited for higher-energy transients; requires larger PCB footprint and different land pattern. | Choose when surge threat level exceeds 400 W or thermal dissipation demands lower RθJA. |
Compared with SMAJ12CAHE3_A/H, the SMAJ12CAHM3_A/H adds halogen-free construction without sacrificing AEC-Q101 qualification or clamping performance; versus SMBJ12CAHM3_A/H, it trades 200 W pulse power headroom for 30% smaller board area and tighter SMT placement tolerance.
Availability
SMAJ12CAHM3_A/H is available at Aetrix Electronics and suitable for automotive electronics, industrial sensor systems, consumer USB interfaces, and telecom power inputs requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for SMAJ12CAHM3_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, TVS devices, and optoelectronics with emphasis on reliability, efficiency, and application-specific optimization.
The SMAJ series is engineered for robust transient suppression in space-constrained, high-reliability applications - particularly targeting automotive, industrial, and communications systems where AEC-Q101 qualification and consistent clamping performance are critical.
FAQ
What does the 'HM3' suffix indicate in SMAJ12CAHM3_A/H?
The 'HM3' suffix in SMAJ12CAHM3_A/H signifies halogen-free, RoHS-compliant construction with matte tin-plated leads and JESD201 Class 2 whisker resistance. It also confirms AEC-Q101 qualification for automotive use, distinguishing it from commercial-grade 'E3' or 'M3' variants. This makes SMAJ12CAHM3_A/H suitable for environmentally regulated and mission-critical applications where material content and reliability are tightly controlled.
Is SMAJ12CAHM3_A/H unidirectional or bidirectional?
SMAJ12CAHM3_A/H is a bidirectional transient voltage suppressor, as confirmed by the 'CA' suffix in its part number. Its electrical characteristics - including VBR, VC, and IPPM - apply identically in both polarities, enabling symmetrical clamping on AC-coupled lines, floating buses, or differential signal pairs without polarity orientation concerns during placement.
What is the maximum clamping voltage of SMAJ12CAHM3_A/H and under what test condition?
The maximum clamping voltage of SMAJ12CAHM3_A/H is 19.9 V, measured at a peak pulse current (IPPM) of 20.1 A using the standardized 10/1000 μs double-exponential waveform. This value represents the upper limit of voltage imposed on the protected circuit during worst-case surge events, directly informing design margins for downstream ICs and MOSFETs.
Does SMAJ12CAHM3_A/H require a heatsink for standard operation?
No, SMAJ12CAHM3_A/H does not require an external heatsink for standard single-pulse or low-duty-cycle transient suppression. Its thermal resistance is specified at 120 °C/W (junction-to-ambient) on a minimum recommended 0.2" × 0.2" copper pad per terminal. For repetitive surges or high ambient temperatures, thermal design should verify junction temperature remains ≤150 °C using RθJA and actual power dissipation.
How does SMAJ12CAHM3_A/H compare to SMAJ12A in terms of functionality?
SMAJ12CAHM3_A/H is bidirectional with symmetrical clamping, while SMAJ12A is unidirectional and conducts only in reverse bias. The 'CA' version supports AC and floating-line protection without polarity constraints, whereas SMAJ12A requires correct cathode orientation and offers forward voltage drop (VF = 3.5 V at 25 A) - a feature absent in SMAJ12CAHM3_A/H. Both share identical VWM, VBR, and PPPM, but their circuit integration differs fundamentally.
SMAJ12CAHM3_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:
- -
- 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_A/H FAQ
1.How can I place an order for SMAJ12CAHM3_A/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ12CAHM3_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 SMAJ12CAHM3_A/H reliable?
The price and inventory of SMAJ12CAHM3_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 SMAJ12CAHM3_A/H is usually 5 days.
3.What payment methods are accepted for SMAJ12CAHM3_A/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ12CAHM3_A/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ12CAHM3_A/H?
SMAJ12CAHM3_A/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ12CAHM3_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 SMAJ12CAHM3_A/H?
For technical support, including SMAJ12CAHM3_A/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ12CAHM3_A/H requirements.
6.How does Aetrix verify that SMAJ12CAHM3_A/H is sourced from the original manufacturer or authorized distributors?
All SMAJ12CAHM3_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 SMAJ12CAHM3_A/H meets industry standards.
7.What is the process for return or replacement of SMAJ12CAHM3_A/H?
All SMAJ12CAHM3_A/H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ12CAHM3_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 SMAJ12CAHM3_A/H part is unused and in its original packaging.
Return procedure for SMAJ12CAHM3_A/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ12CAHM3_A/H Tags
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