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Vishay General Semiconductor - Diodes Division SMAJ51AHM3_A/I
- Part No.:
- SMAJ51AHM3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ51AHM3_A/I.pdf
- Description:
- TVS DIODE 51VWM 82.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,520
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Product details
Overview
SMAJ51AHM3_A/I 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/I datasheet, SMAJ51AHM3_A/I pinout, SMAJ51AHM3_A/I application, or SMAJ51AHM3_A/I equivalent, this device serves as a halogen-free, RoHS-compliant, AEC-Q101-qualified TVS for high-reliability transient suppression where low clamping voltage, fast response (<1 ns), and stable thermal performance up to +150 °C junction temperature are required.
Technical Context
This unidirectional TVS operates by avalanche breakdown when reverse voltage exceeds VBR, limiting transient energy via low dynamic impedance and clamping to ≤82.4 V at 4.9 A. Its glass-passivated junction ensures stable leakage (<1 μA at 51 V) and repeatable surge handling across temperature.
Designed for PCB-level protection of DC power inputs and low-speed signal paths, it delivers 400 W peak pulse power (derated to 300 W above 78 V), supports 40 A non-repetitive forward surge (8.3 ms half-sine), and maintains thermal resistance of 120 °C/W (junction-to-ambient) on standard 0.2" × 0.2" copper pads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC bias margin for protected line. |
| VBR (min/max) | 56.7 V / 62.7 V at 1 mA - Confirmed breakdown threshold range; ensures reliable turn-on without premature conduction. |
| VC @ IPPM | 82.4 V at 4.9 A - Measured clamping voltage under 10/1000 μs surge; determines maximum stress imposed on downstream ICs. |
| PPPM | 400 W - Peak pulse power handling capability; enables robust protection against IEC 61000-4-5 Level 3 surges. |
| IFSM | 40 A - Non-repetitive forward surge rating (8.3 ms); supports inrush current immunity during power-up events. |
| TJ max | +150 °C - Maximum junction temperature; allows operation in under-hood automotive and industrial environments. |
| Package | SMA (DO-214AC) - Surface-mount outline with cathode band marking; compatible with automated placement and reflow soldering. |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with matte tin-plated leads, MSL Level 1 (JEDEC J-STD-020), 260 °C peak reflow profile.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry / transient return path | Connected to ground or low-impedance return plane; completes clamping loop during overvoltage events. |
| Cathode | Protected line connection | Connected to the line being protected (e.g., 51 V rail); polarity band identifies this terminal on the device body. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control units and ADAS power supplies per stress test requirements. |
| Halogen-free & RoHS-compliant | Meets environmental compliance mandates for industrial and consumer electronics without compromising surge robustness. |
| 400 W peak pulse power (10/1000 μs) | Supports repeated transient suppression in 24 V and 48 V systems without thermal runaway under defined duty cycle (0.01 %). |
| Low clamping ratio (VC/VWM = 1.62) | Minimizes overvoltage stress on protected ICs compared to higher-ratio TVS devices, improving system-level reliability. |
| Fast response time (<1 ns) | Clamps transients before sensitive circuitry experiences damaging voltage overshoot, critical for MOSFET gate protection. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
|
Use Scenario: 12 V/24 V battery-fed ECUs exposed to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Unidirectional TVS placed between power input and ground to clamp transients before they reach PMICs or microcontrollers. Use Value: Limits peak voltage to 82.4 V during 4.9 A surge, preventing latch-up or oxide breakdown in downstream 3.3 V/5 V logic. |
Use Scenario: Analog output lines from pressure or temperature sensors in factory automation PLCs. IC Role / Device Role / Timing Role: TVS mounted at connector entry point to suppress ESD and inductive switching noise coupled onto 4–20 mA or 0–10 V signal paths. Use Value: Sub-1 ns response prevents signal corruption during 8 kV contact ESD events while maintaining <1 μA leakage at 51 V operating bias. |
| DC-DC Converter Input Protection | Motor Drive Gate Driver Protection |
|
Use Scenario: Input stage of isolated 48 V-to-12 V buck converters in telecom power systems. IC Role / Device Role / Timing Role: Primary transient shunt on high-side input rail, coordinated with upstream fuse and common-mode choke. Use Value: Withstands 400 W surges without degradation, enabling compliance with IEC 61000-4-5 (4 kV, 2 Ω source) test requirements. |
Use Scenario: Protection of high-side N-channel MOSFET gate drivers in BLDC motor controllers. IC Role / Device Role / Timing Role: Clamps Miller-induced voltage spikes during fast switching transitions on gate drive traces. Use Value: Low VC (82.4 V) prevents gate oxide overstress while low incremental resistance minimizes clamping delay impact on switching timing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ51AHE3_A/I | Same electrical specs, but RoHS-compliant (non-halogen-free) version; no halogen restriction compliance. | Acceptable for commercial/industrial use where halogen-free mandate does not apply. | Select SMAJ51AHM3_A/I when halogen-free material compliance is required per IPC-1752 or EU directives. |
| SMAJ51A-M3/5A | Identical halogen-free specification, but packaged in 13" tape-and-reel (7500 pcs) vs. I-code's 7500 pcs in 13" reel with different packaging suffix. | No functional difference; only logistics and traceability distinction (I-code denotes specific revision and reel labeling). | Choose SMAJ51AHM3_A/I for full alignment with Vishay's AEC-Q101-qualified, halogen-free, and revision-controlled supply chain. |
Compared with SMAJ51AHE3_A/I and SMAJ51A-M3/5A, the SMAJ51AHM3_A/I uniquely combines halogen-free construction, AEC-Q101 qualification, and documented revision 'A' traceability - making it the preferred choice for automotive Tier 1 suppliers requiring full material and process compliance documentation.
Availability
SMAJ51AHM3_A/I is available at Aetrix Electronics and suitable for automotive power rail protection, industrial sensor interface hardening, and DC-DC converter input surge suppression requiring stable component supply, long-term lifecycle support, and full AEC-Q101 traceability.
Supply support for SMAJ51AHM3_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, and protection devices with emphasis on reliability, efficiency, and application-specific optimization.
The SMAJ series was developed for high-energy transient suppression in space-constrained, high-reliability applications - particularly automotive, industrial, and telecom power systems demanding AEC-Q101 validation and consistent clamping performance.
FAQ
What is the clamping voltage of the SMAJ51AHM3_A/I under a 10/1000 μs surge?
The SMAJ51AHM3_A/I has a maximum clamping voltage (VC) of 82.4 V at 4.9 A peak pulse current (IPPM) under the standardized 10/1000 μs waveform. This value is measured per ANSI/IEEE C62.35 and defines the upper voltage limit imposed on protected circuitry during transient events - critical for ensuring downstream ICs remain within absolute maximum ratings. The SMAJ51AHM3_A/I achieves this with low dynamic impedance and stable thermal behavior up to +150 °C junction temperature.
Is the SMAJ51AHM3_A/I suitable for automotive applications?
Yes, the SMAJ51AHM3_A/I is AEC-Q101 qualified and explicitly designated for automotive use with ordering code suffix 'HM3'. It meets stress test requirements for temperature cycling, humidity, mechanical shock, and surge endurance relevant to engine control, body electronics, and ADAS subsystems. Its halogen-free, RoHS-compliant construction and revision-controlled traceability ('A' suffix) further align with Tier 1 automotive sourcing mandates - distinguishing it from non-qualified variants like SMAJ51A-E3.
How does the SMAJ51AHM3_A/I differ from the SMAJ51AHE3_A/I?
The SMAJ51AHM3_A/I and SMAJ51AHE3_A/I share identical electrical parameters (VWM = 51 V, VC = 82.4 V, PPPM = 400 W), but differ in material compliance: HM3 denotes halogen-free construction per IEC 61249-2-21, while HE3 is RoHS-compliant but not halogen-free. Both are AEC-Q101 qualified and use the same SMA (DO-214AC) package. The SMAJ51AHM3_A/I is specified for applications requiring full halogen-free certification, such as European automotive programs or green electronics initiatives.
What is the thermal resistance of the SMAJ51AHM3_A/I, and how does it affect layout?
The SMAJ51AHM3_A/I has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W when mounted on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. This value assumes minimum recommended pad layout per Vishay's datasheet - underscoring the need for adequate copper area to sustain repetitive surge duty cycles. For high-frequency or high-duty-cycle applications, designers should verify junction temperature rise using actual board layout and ambient conditions, as exceeding +150 °C TJ risks parametric shift or failure. The SMAJ51AHM3_A/I also features RθJL = 30 °C/W for lead-based thermal modeling.
Does the SMAJ51AHM3_A/I have polarity marking, and how is it identified?
Yes, the SMAJ51AHM3_A/I is a unidirectional TVS and features a visible cathode band on the SMA (DO-214AC) package body - located at the cathode end. This band must be oriented toward the line being protected (e.g., 51 V rail), while the anode connects to ground or reference potential. Incorrect polarity results in forward conduction during normal operation and failure to clamp reverse transients. The marking is consistent across all SMAJ unidirectional variants and verified per JEDEC DO-214AC mechanical drawings in the Vishay datasheet (Document Number: 88390).
SMAJ51AHM3_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:
- 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/I FAQ
1.How can I place an order for SMAJ51AHM3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ51AHM3_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 SMAJ51AHM3_A/I reliable?
The price and inventory of SMAJ51AHM3_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 SMAJ51AHM3_A/I is usually 5 days.
3.What payment methods are accepted for SMAJ51AHM3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ51AHM3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ51AHM3_A/I?
SMAJ51AHM3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ51AHM3_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 SMAJ51AHM3_A/I?
For technical support, including SMAJ51AHM3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ51AHM3_A/I requirements.
6.How does Aetrix verify that SMAJ51AHM3_A/I is sourced from the original manufacturer or authorized distributors?
All SMAJ51AHM3_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 SMAJ51AHM3_A/I meets industry standards.
7.What is the process for return or replacement of SMAJ51AHM3_A/I?
All SMAJ51AHM3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ51AHM3_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 SMAJ51AHM3_A/I part is unused and in its original packaging.
Return procedure for SMAJ51AHM3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ51AHM3_A/I Tags
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