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Vishay General Semiconductor - Diodes Division SMAJ51AHE3_A/I
- Part No.:
- SMAJ51AHE3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ51AHE3_A/I.pdf
- Description:
- TVS DIODE 51VWM 82.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:4,211
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Product details
Overview
SMAJ51AHE3_A/I from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for robust overvoltage protection in power and signal lines. It features a 51 V standoff voltage (VWM), 56.7–62.7 V breakdown voltage (VBR) at 1 mA, 4.9 A peak pulse current (IPPM), and clamps transients to ≤82.4 V under 10/1000 μs waveform - deployed in automotive power supplies, industrial sensor interfaces, and DC-DC converter input stages.
For engineers reviewing the SMAJ51AHE3_A/I datasheet, SMAJ51AHE3_A/I pinout, SMAJ51AHE3_A/I application, or SMAJ51AHE3_A/I equivalent, key selection criteria include its AEC-Q101 qualification, 400 W peak pulse power rating (10/1000 μs), SMA (DO-214AC) package compatibility with automated placement, and low 0.05 Ω incremental surge resistance enabling fast, low-clamp protection of sensitive MOSFETs and ICs.
Technical Context
This unidirectional TVS diode operates as a clamping device that remains high-impedance below 51 V and rapidly avalanches above ~56.7 V to limit transient energy. Its glass-passivated junction ensures stable breakdown characteristics and long-term reliability under repetitive surge stress.
Designed for PCB-level protection, it responds in <1 ps to ESD and lightning-induced surges, with thermal resistance RθJA = 120 °C/W and RθJL = 30 °C/W - requiring minimal copper pad area (0.2" × 0.2") for full 400 W rating up to TA = 25 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM (Stand-off Voltage) | 51 V - maximum continuous reverse operating voltage before conduction begins |
| VBR (Breakdown Voltage) | 56.7–62.7 V at IT = 1 mA - precise avalanche threshold defining clamping onset |
| VC (Clamping Voltage) | ≤82.4 V at IPPM = 4.9 A (10/1000 μs) - peak voltage seen by protected circuit during surge |
| PPPM (Peak Pulse Power) | 400 W - maximum transient energy absorption capability under standard waveform |
| IFSM (Surge Current) | 40 A - single half-sine 8.3 ms forward surge rating for unidirectional operation |
| TJ max. | +150 °C - maximum junction temperature enabling use in under-hood automotive environments |
| Package | SMA (DO-214AC) - industry-standard surface-mount outline with cathode band marking |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with matte tin-plated leads; polarity indicated by cathode band on unidirectional devices.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side connection in clamping configuration | Connected to ground or low-impedance return path; carries full surge current during avalanche |
| Cathode | High-side connection; marked with band | Connected to protected line (e.g., 51 V rail); defines unidirectional conduction direction |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and surge endurance per JESD22-A108 |
| 400 W peak pulse power (10/1000 μs) | Supports IEC 61000-4-5 Level 4 (4 kV) surge immunity without derating on standard PCB pads |
| Low clamping ratio (VC/VBR ≈ 1.35) | Minimizes overvoltage stress on downstream MOSFETs or regulators during transient events |
| MSL Level 1 (JEDEC J-STD-020) | Enables lead-free reflow assembly without moisture sensitivity concerns or baking requirements |
| Glass-passivated junction | Ensures stable VBR tolerance and low leakage (<1 μA at VWM) across temperature and lifetime |
Applications
| Automotive Power Rail Protection | Industrial Sensor Signal Line Protection |
|---|---|
Use Scenario: Protecting 5V/12V/24V power inputs in engine control units (ECUs) and body control modules against load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Unidirectional clamping TVS placed between supply rail and chassis ground to shunt surge energy before reaching LDOs or microcontrollers. Use Value: Clamps 12 V system transients to ≤82.4 V within nanoseconds, preserving integrity of 3.3 V logic rails downstream via tight VC margin. |
Use Scenario: Safeguarding analog outputs (e.g., 4–20 mA loops) and digital I/O (CAN, LIN) in factory automation sensors exposed to ESD and inductive switching noise. IC Role / Device Role / Timing Role: Low-capacitance TVS mounted at connector entry point to absorb ±8 kV contact ESD (IEC 61000-4-2) and 1 kV ring wave surges. Use Value: Sub-100 pF junction capacitance avoids signal distortion on 1 Mbps CAN lines while delivering full 400 W surge handling. |
| DC-DC Converter Input Stage | Consumer Device USB Port Protection |
Use Scenario: Input protection for buck converters in telecom power supplies subjected to 100 V/100 ns fast transients per IEC 61000-4-4. IC Role / Device Role / Timing Role: Primary clamping element placed upstream of input filter capacitors to prevent overstress of MOSFETs and controller ICs. Use Value: Fast response (<1 ps) and low dynamic impedance ensure clamping occurs before input capacitor voltage overshoot exceeds rated limits. |
Use Scenario: Overvoltage suppression on VBUS lines of USB-C ports in portable electronics against hot-plug transients and adapter faults. IC Role / Device Role / Timing Role: Standoff-rated TVS absorbing >100 A surge currents from faulty chargers while maintaining <51 V steady-state operation. Use Value: RoHS-compliant and halogen-free (HE3 suffix) construction meets consumer safety and environmental compliance mandates without sacrificing surge performance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ51A-E3/61 | Same electrical specs; commercial-grade (non-AEC-Q101), 7" tape/reel (1800 pcs) | Lacks automotive qualification; suitable for industrial/commercial designs without automotive lifecycle requirements | Select when AEC-Q101 is not mandated and smaller reel size aligns with SMT line setup |
| SMAJ51AHM3_A/I | Identical ratings and AEC-Q101 qualification; halogen-free molding compound | Meets stricter environmental standards (e.g., JIS C 0950) where brominated flame retardants are prohibited | Choose for green manufacturing programs requiring halogen-free compliance without compromising surge performance |
Compared with SMAJ51AHE3_A/I, the SMAJ51A-E3/61 offers identical protection performance but lacks automotive qualification and uses a smaller reel format, while SMAJ51AHM3_A/I delivers identical AEC-Q101 reliability with halogen-free materials - making SMAJ51AHE3_A/I the optimal balance of automotive compliance, RoHS adherence, and high-volume 13" reel logistics.
Availability
SMAJ51AHE3_A/I is available at Aetrix Electronics and suitable for automotive ECUs, industrial sensor nodes, DC-DC converter inputs, and USB power delivery systems requiring stable component supply across multi-year production cycles.
Supply support for SMAJ51AHE3_A/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, 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 validation, and consistent clamping performance are critical.
FAQ
What is the clamping voltage of SMAJ51AHE3_A/I at its rated peak pulse current?
The SMAJ51AHE3_A/I clamps to a maximum of 82.4 V when subjected to its rated peak pulse current of 4.9 A under the standardized 10/1000 μs waveform. This value is measured at TA = 25 °C with specified PCB pad layout and represents the upper voltage limit imposed on protected circuitry during surge events - a critical parameter for ensuring downstream components remain within safe operating voltage margins.
Is SMAJ51AHE3_A/I qualified for automotive applications?
Yes, SMAJ51AHE3_A/I is AEC-Q101 qualified, meaning it has passed rigorous stress tests including high-temperature reverse bias, temperature cycling, and surge endurance specifically required for automotive electronic components. The "HE3" suffix explicitly denotes RoHS-compliant and AEC-Q101 qualified construction, making SMAJ51AHE3_A/I suitable for under-hood and chassis-mounted modules in passenger vehicles and commercial vehicles.
What package type does SMAJ51AHE3_A/I use, and what are its mounting requirements?
SMAJ51AHE3_A/I uses the SMA (DO-214AC) surface-mount package, featuring a cathode band for polarity identification and matte tin-plated leads compatible with J-STD-002 solderability standards. For full 400 W rating, it must be mounted on minimum 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal; reduced pad area requires derating per Figure 2 in the Vishay datasheet 88390.
How does SMAJ51AHE3_A/I differ from bidirectional variants like SMAJ51CA?
SMAJ51AHE3_A/I is unidirectional, conducting only in reverse bias above VBR, with a defined cathode band; SMAJ51CA is bidirectional and symmetrical, offering clamping in both polarities without polarity marking. SMAJ51AHE3_A/I is used where DC bias exists (e.g., positive supply rails), while SMAJ51CA suits AC-coupled or floating signal lines - their VBR, VC, and PPPM values are otherwise matched per datasheet Table 1.
What is the maximum junction temperature and thermal resistance of SMAJ51AHE3_A/I?
The SMAJ51AHE3_A/I has a maximum junction temperature (TJ) of +150 °C and typical thermal resistances of RθJA = 120 °C/W (junction-to-ambient) and RθJL = 30 °C/W (junction-to-lead). These values assume standard PCB mounting per Vishay's recommended pad layout; actual thermal performance depends on board copper area, airflow, and adjacent heat sources - critical for sustained surge duty cycles in enclosed automotive enclosures.
SMAJ51AHE3_A/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:
- 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:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ51AHE3_A/I FAQ
1.How can I place an order for SMAJ51AHE3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ51AHE3_A/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 SMAJ51AHE3_A/I reliable?
The price and inventory of SMAJ51AHE3_A/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ51AHE3_A/I is usually 5 days.
3.What payment methods are accepted for SMAJ51AHE3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ51AHE3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ51AHE3_A/I?
SMAJ51AHE3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ51AHE3_A/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 SMAJ51AHE3_A/I?
For technical support, including SMAJ51AHE3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ51AHE3_A/I requirements.
6.How does Aetrix verify that SMAJ51AHE3_A/I is sourced from the original manufacturer or authorized distributors?
All SMAJ51AHE3_A/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 SMAJ51AHE3_A/I meets industry standards.
7.What is the process for return or replacement of SMAJ51AHE3_A/I?
All SMAJ51AHE3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ51AHE3_A/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 SMAJ51AHE3_A/I part is unused and in its original packaging.
Return procedure for SMAJ51AHE3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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