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Vishay General Semiconductor - Diodes Division SMAJ51AHM3_A/H
- Part No.:
- SMAJ51AHM3_A/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ51AHM3_A/H.pdf
- Description:
- TVS DIODE 51VWM 82.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,075
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Product details
Overview
SMAJ51AHM3_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 51 V stand-off voltage (VWM), 56.7–62.7 V breakdown voltage (VBR) at 1 mA, 82.4 V maximum clamping voltage (VC) at 4.9 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 power rails.
For engineers reviewing the SMAJ51AHM3_A/H datasheet, SMAJ51AHM3_A/H pinout, SMAJ51AHM3_A/H application, or SMAJ51AHM3_A/H equivalent, this device delivers verified transient suppression for 12 V–48 V DC systems, supports AEC-Q101 qualification (via HM3 suffix), and meets J-STD-020 MSL Level 1 reflow requirements up to 260 °C.
Technical Context
This unidirectional TVS diode operates as a fast-acting shunt clamp during overvoltage events, leveraging a glass-passivated silicon junction for low leakage (<1 μA at 51 V) and sub-nanosecond response time. Its thermal resistance (RθJA = 120 °C/W) and 150 °C max junction temperature enable reliable operation under repetitive surge conditions when mounted on 5.0 mm × 5.0 mm copper pads.
The SMAJ51AHM3_A/H complies with ANSI/IEEE C62.35 surge standards and is rated for 40 A non-repetitive forward surge current (IFSM, 8.3 ms half-sine). Its halogen-free, RoHS-compliant construction (HM3 suffix) and matte tin-plated leads meet JESD 22-B102 solderability and JESD 201 Class 2 whisker resistance requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous reverse operating voltage before clamping begins; sets safe margin above 48 V nominal rail. |
| VBR (min/max) | 56.7 V / 62.7 V at 1 mA - Confirmed breakdown range ensures predictable turn-on across production lot and temperature. |
| VC @ IPPM | 82.4 V at 4.9 A - Clamping voltage limits downstream component stress during 10/1000 μs transients. |
| PPPM | 400 W - Peak pulse power handling capacity for standard lightning/surge immunity testing per IEC 61000-4-5. |
| IFSM | 40 A - Withstands single half-sine surges up to 8.3 ms, protecting against inductive switch-off spikes in motor drivers. |
| TJ max | 150 °C - Enables use in under-hood automotive environments and enclosed industrial enclosures without derating. |
| Package | SMA (DO-214AC) - Low-profile SMD footprint (4.93 mm × 3.99 mm) compatible with automated pick-and-place and reflow. |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, cathode-indicated by band on body. Dimensions: 4.93 mm × 3.99 mm × 2.29 mm (L × W × H); terminals are matte tin-plated, solderable per J-STD-002.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry point during forward conduction | Connected to lower-potential side of protected line (e.g., ground or return path). |
| Cathode | Current exit point during reverse-biased clamping | Connected to higher-potential side (e.g., 48 V rail); band-marked terminal defines polarity. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified (HM3 suffix) | Validated for automotive powertrain and chassis applications requiring zero-failure reliability under thermal cycling and vibration. |
| 400 W peak pulse power (10/1000 μs) | Meets IEC 61000-4-5 Level 4 surge immunity for 48 V board-level protection without external heat sinking. |
| Glass passivated junction | Ensures stable VBR tolerance (±5 %), low leakage (<1 μA), and long-term stability under humidity and bias stress. |
| MSL Level 1 (260 °C peak) | Supports standard lead-free reflow profiles without popcorn cracking or delamination risk. |
| Halogen-free & RoHS-compliant | Fulfills EU ELV and China RoHS requirements for automotive and industrial end-equipment compliance. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
|
Use Scenario: Suppressing load-dump transients (up to 60 V, 100 ms) on 48 V battery-fed ECUs in ADAS domain controllers. IC Role / Device Role / Timing Role: Shunt-clamp TVS placed between VBAT and GND, activated within <1 ns to limit voltage excursion below 85 V. Use Value: Prevents latch-up or gate oxide damage in 48 V buck converters and CAN FD transceivers during alternator regulation faults. |
Use Scenario: Guarding analog inputs of 24 V industrial PLC analog I/O modules against ESD and inductive kickback from solenoid valves. IC Role / Device Role / Timing Role: Unidirectional clamping element on signal line (e.g., 4–20 mA loop supply), referenced to local ground. Use Value: Limits transient overshoot to ≤82.4 V while maintaining <1 μA leakage at 24 V, preserving ADC accuracy and isolation integrity. |
| Telecom DC Power Input Protection | Consumer Appliance Motor Drive Protection |
|
Use Scenario: Safeguarding PoE++ (802.3bt Type 4) powered devices against surge coupling from Ethernet cabling and AC/DC adapter transients. IC Role / Device Role / Timing Role: Primary front-end TVS on 57 V DC input rail, upstream of DC-DC converter and hot-swap controller. Use Value: Absorbs 400 W surges without degradation, enabling compliance with UL 62368-1 Annex Q surge withstand requirements. |
Use Scenario: Protecting BLDC motor driver FETs in cordless power tools during commutation-induced voltage spikes and battery reversal events. IC Role / Device Role / Timing Role: Reverse-polarity and transient suppressor across high-side FET source-drain, referenced to tool battery pack negative. Use Value: Clamps spikes to 82.4 V while surviving 40 A 8.3 ms surges, preventing avalanche failure in 60 V-rated MOSFETs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ51AHE3_A/H | Same electrical specs, but RoHS-compliant commercial grade (E3) without halogen-free certification. | Lacks halogen-free compliance; suitable for non-automotive industrial use where material restrictions are less stringent. | Select when halogen-free requirement is not mandated and cost optimization is prioritized. |
| SMAJ51AHE3_A/I | Identical electrical and material specs, but supplied in 13" tape-and-reel (7500 pcs) vs. 7" reel (1800 pcs) for high-volume SMT lines. | No functional difference; optimized for large-batch automated assembly with reduced changeover frequency. | Choose for high-throughput manufacturing where reel size and quantity align with production planning. |
Compared with SMAJ51AHM3_A/H, the E3 variant trades halogen-free status for slightly lower unit cost in non-automotive settings, while the /A/I version offers identical performance in larger reels - both retain full pinout, clamping behavior, and thermal ratings.
Availability
SMAJ51AHM3_A/H is available at Aetrix Electronics and suitable for automotive power rail protection, industrial sensor interface hardening, and telecom DC input surge suppression requiring stable component supply, AEC-Q101 qualification, and halogen-free compliance.
Supply support for SMAJ51AHM3_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, and protection devices with emphasis on reliability, power efficiency, and automotive-grade validation.
The SMAJ series was engineered specifically for robust transient suppression in harsh environments - targeting 12 V to 188 V DC systems in automotive, industrial, and telecom infrastructure where fast response and repeatable clamping are critical.
FAQ
What is the clamping voltage of SMAJ51AHM3_A/H at its rated peak pulse current?
The SMAJ51AHM3_A/H has a maximum clamping voltage (VC) of 82.4 V at its specified peak pulse current (IPPM) of 4.9 A, measured under the standard 10/1000 μs double-exponential surge waveform. This value ensures downstream components like 100 V-rated MOSFETs remain within safe operating limits during transient events. The clamping performance is guaranteed across the full operating temperature range of −55 °C to +150 °C.
Is SMAJ51AHM3_A/H qualified for automotive applications?
Yes, SMAJ51AHM3_A/H is AEC-Q101 qualified, as confirmed by the "HM3" suffix denoting halogen-free, RoHS-compliant, and automotive-grade construction. It undergoes stress testing for temperature cycling, mechanical shock, and humidity resistance per AEC-Q101 Rev D, making it suitable for engine control units, body electronics, and ADAS power supplies where reliability under thermal and vibration stress is mandatory.
How does the SMAJ51AHM3_A/H differ from the SMAJ51A-E3 variant?
The SMAJ51AHM3_A/H differs from SMAJ51A-E3 in three key ways: it uses halogen-free molding compound (vs. standard RoHS), carries AEC-Q101 qualification (vs. commercial grade only), and features matte tin plating meeting JESD 201 Class 2 whisker resistance (vs. JESD 201 Class 1). All electrical parameters - VWM, VBR, VC, PPPM - are identical between SMAJ51AHM3_A/H and SMAJ51A-E3.
What PCB pad layout is recommended for optimal thermal performance of SMAJ51AHM3_A/H?
Vishay specifies a minimum 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pad area per terminal for SMAJ51AHM3_A/H to achieve its rated 400 W peak pulse power. Using smaller pads reduces thermal dissipation capability and may cause premature failure under repeated surges. The SMA (DO-214AC) package's RθJA of 120 °C/W assumes this pad layout; reducing pad size increases junction temperature rise proportionally.
Can SMAJ51AHM3_A/H be used in bidirectional protection circuits?
No, SMAJ51AHM3_A/H is a unidirectional TVS diode, indicated by the "A" suffix and cathode band marking. For bidirectional protection, Vishay offers the SMAJ51CA family (e.g., SMAJ51CAHM3_A/H), which provides symmetrical clamping in both polarities. Using SMAJ51AHM3_A/H in reverse-biased configurations beyond its 51 V stand-off voltage will cause permanent breakdown and failure.
SMAJ51AHM3_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):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 82.4V
- Current - Peak Pulse (10/1000µs):
- 4.9A
- 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)
SMAJ51AHM3_A/H FAQ
1.How can I place an order for SMAJ51AHM3_A/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ51AHM3_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 SMAJ51AHM3_A/H reliable?
The price and inventory of SMAJ51AHM3_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 SMAJ51AHM3_A/H is usually 5 days.
3.What payment methods are accepted for SMAJ51AHM3_A/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ51AHM3_A/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ51AHM3_A/H?
SMAJ51AHM3_A/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ51AHM3_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 SMAJ51AHM3_A/H?
For technical support, including SMAJ51AHM3_A/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ51AHM3_A/H requirements.
6.How does Aetrix verify that SMAJ51AHM3_A/H is sourced from the original manufacturer or authorized distributors?
All SMAJ51AHM3_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 SMAJ51AHM3_A/H meets industry standards.
7.What is the process for return or replacement of SMAJ51AHM3_A/H?
All SMAJ51AHM3_A/H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ51AHM3_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 SMAJ51AHM3_A/H part is unused and in its original packaging.
Return procedure for SMAJ51AHM3_A/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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