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Vishay General Semiconductor - Diodes Division SMAJ51AHE3/5A
- Part No.:
- SMAJ51AHE3/5A
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ51AHE3/5A.pdf
- Description:
- TVS DIODE 51VWM 82.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:5,265
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Product details
Overview
SMAJ51AHE3/5A from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode designed for primary overvoltage protection of sensitive ICs, MOSFETs, and signal lines. It features a 51 V standoff voltage (VWM), 56.7–62.7 V breakdown range at 1 mA, 82.4 V maximum clamping voltage at 4.9 A peak pulse current, and 400 W peak pulse power rating with 10/1000 μs waveform - deployed in automotive power supply rails and industrial sensor interfaces.
For engineers reviewing the SMAJ51AHE3/5A datasheet, SMAJ51AHE3/5A pinout, SMAJ51AHE3/5A application, or SMAJ51AHE3/5A equivalent, key selection criteria include clamping performance under 4.9 A surge, unidirectional polarity marking, AEC-Q101 qualification status, and compatibility with SMA (DO-214AC) PCB footprints in high-reliability 12 V/24 V systems.
Technical Context
This TVS diode operates as a voltage-clamped shunt protector: when transient voltage exceeds its breakdown threshold (VBR = 56.7–62.7 V), it rapidly avalanches to limit downstream voltage to ≤82.4 V. Its glass-passivated junction ensures stable leakage (<1.0 μA at 51 V) and fast response time (<1.0 ps), enabling effective suppression of ESD, load dump, and inductive switching transients.
The device is rated for 40 A non-repetitive forward surge (8.3 ms half-sine), supports 150 °C max junction temperature, and exhibits low incremental surge resistance - critical for maintaining clamping integrity during multi-pulse stress events in automotive ECUs and industrial PLC I/O modules.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous reverse operating voltage before conduction begins; defines safe DC/AC working margin in 48 V nominal systems. |
| VBR min/max | 56.7 V / 62.7 V at 1 mA - Confirmed breakdown range ensures reliable turn-on without premature triggering in noisy environments. |
| VC @ IPPM | 82.4 V at 4.9 A - Clamping voltage under full-rated 10/1000 μs surge; determines maximum stress imposed on protected circuitry. |
| PPPM | 400 W - Peak pulse power handling per 10/1000 μs waveform; enables robust protection against ISO 7637-2 Pulse 1/2/5a transients. |
| IFSM | 40 A - Peak forward surge current rating (8.3 ms half-sine); validates survivability during automotive load-dump events. |
| TJ max | +150 °C - Maximum junction temperature; supports operation in under-hood and industrial control cabinet environments. |
| RθJA | 120 °C/W - Thermal resistance junction-to-ambient on standard 0.2" × 0.2" copper pads; informs derating requirements above 25 °C ambient. |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, low-profile case with matte tin-plated leads solderable per J-STD-002. Cathode indicated by banded end; anode is opposite terminal.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Transient current sink | Connected to protected line; conducts surge current to ground when VIN > VBR. |
| Anode | Reference/ground return | Typically tied to system ground plane; completes clamping path during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control, body electronics, and ADAS power domains. |
| 400 W peak pulse power (10/1000 μs) | Meets ISO 7637-2 Pulse 5a requirements for 24 V systems with minimal layout impact. |
| Low clamping ratio (VC/VBR ≈ 1.31) | Minimizes voltage overshoot during transients, reducing risk of latch-up or gate oxide damage in protected MOSFETs. |
| MSL Level 1 (260 °C reflow) | Enables single-pass lead-free assembly without moisture sensitivity concerns or baking requirements. |
| Glass passivated junction | Ensures stable leakage (<1.0 μA at VWM) and long-term reliability under thermal cycling and humidity stress. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Signal Line Protection |
|---|---|
Use Scenario: Installed across 12 V battery feed to MCU power input in vehicle door module to suppress load dump and jump-start transients. IC Role / Device Role / Timing Role: Unidirectional shunt TVS clamping transient energy before it reaches LDO regulator and microcontroller. Use Value: Limits peak voltage to 82.4 V during 4.9 A surge, preventing brownout reset or permanent damage to 5 V logic supply chain. | Use Scenario: Placed on analog output line (4–20 mA) of pressure sensor in factory automation PLC rack. IC Role / Device Role / Timing Role: Fast-acting voltage clamp protecting op-amp output stage and ADC front-end from ESD and cable-induced surges. Use Value: Sub-nanosecond response and <1.0 μA leakage at 51 V maintain signal integrity and measurement accuracy over 15+ year service life. |
| Telecom DC Power Interface | Consumer Device USB Port Protection |
Use Scenario: Mounted on 48 V PoE+ midspan injector output to safeguard Ethernet PHY transceivers from induced lightning surges. IC Role / Device Role / Timing Role: Primary overvoltage clamp limiting transient excursion to ≤82.4 V during 10/1000 μs events up to 400 W. Use Value: Enables compliance with IEC 61000-4-5 Level 3 (2 kV line-earth) while preserving 48 V DC delivery stability. | Use Scenario: Integrated into USB-C port ESD protection stack on smart speaker mainboard near VBUS line. IC Role / Device Role / Timing Role: Secondary clamping device backing up polymer PTC and capacitive ESD array for high-energy surge events. Use Value: Withstands 40 A 8.3 ms surge per IEC 61000-4-4, preventing catastrophic failure during accidental 24 V adapter misconnection. |
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-E3/5A | No AEC-Q101 qualification; commercial-grade only; identical electrical specs and package. | Suitable for non-automotive industrial or consumer designs where automotive qualification is not mandated. | Select when cost sensitivity outweighs automotive reliability validation requirements. |
| SMAJ51AHM3/5A | Halogen-free, RoHS-compliant variant; same AEC-Q101 qualification and electrical performance. | Required for strict environmental compliance programs (e.g., EU automotive Tier 1 supply chains). | Choose when halogen-free material declaration is mandatory for final product certification. |
Compared with SMAJ51AHE3/5A, the SMAJ51A-E3/5A offers identical protection performance without automotive qualification, while SMAJ51AHM3/5A adds halogen-free compliance - both retain the same SMA footprint and clamping behavior, enabling direct substitution where qualification or material constraints permit.
Availability
SMAJ51AHE3/5A is available at Aetrix Electronics and suitable for automotive electronic control units, industrial sensor interfaces, and telecom DC power systems requiring stable component supply with AEC-Q101 assurance and long-term production continuity.
Supply support for SMAJ51AHE3/5A 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 and application-specific performance.
The SMAJ series is engineered for robust transient suppression in harsh environments - targeting automotive, industrial, and telecom applications where high pulse power, low clamping, and AEC-Q101 validation are essential.
FAQ
What is the clamping voltage of SMAJ51AHE3/5A at its rated peak pulse current?
The SMAJ51AHE3/5A has a maximum clamping voltage (VC) of 82.4 V at its rated peak pulse current of 4.9 A (10/1000 μs waveform). This value is measured under standardized test conditions and defines the upper voltage limit imposed on protected circuitry during surge events - a critical parameter for ensuring downstream ICs remain within absolute maximum ratings.
Is SMAJ51AHE3/5A qualified to AEC-Q101, and what does that mean for automotive use?
Yes, SMAJ51AHE3/5A is AEC-Q101 qualified, confirming it has passed stress tests for temperature cycling, humidity, mechanical shock, and lifetime reliability required for automotive electronic components. This qualification validates SMAJ51AHE3/5A for deployment in engine control, body electronics, and infotainment systems where failure could impact safety or functionality.
What is the standoff voltage (VWM) of SMAJ51AHE3/5A, and how does it relate to system voltage?
The standoff voltage (VWM) of SMAJ51AHE3/5A is 51 V - the maximum continuous reverse voltage it can block without significant leakage. For proper operation, this must exceed the system's normal operating voltage (e.g., 48 V nominal telecom or 36 V automotive battery) while leaving margin below the breakdown threshold to avoid false triggering during ripple or noise.
Does SMAJ51AHE3/5A have polarity marking, and how is it identified on the package?
Yes, SMAJ51AHE3/5A is unidirectional and features a cathode band on the SMA (DO-214AC) package - a visible dark stripe near one end. The banded terminal is the cathode and must be connected toward the side of the circuit to be protected (e.g., VIN), while the anode connects to ground or reference potential to complete the clamping path.
What is the thermal resistance and power dissipation capability of SMAJ51AHE3/5A in typical PCB layout?
SMAJ51AHE3/5A has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W when mounted on 0.2" × 0.2" copper pads per terminal. Its steady-state power dissipation (PD) is 3.3 W at 50 °C ambient - sufficient for leakage-related heating but not for continuous conduction; it is designed for transient, not steady-state, energy absorption.
SMAJ51AHE3/5A 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:
- 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)
SMAJ51AHE3/5A FAQ
1.How can I place an order for SMAJ51AHE3/5A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ51AHE3/5A 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 SMAJ51AHE3/5A reliable?
The price and inventory of SMAJ51AHE3/5A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ51AHE3/5A is usually 5 days.
3.What payment methods are accepted for SMAJ51AHE3/5A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ51AHE3/5A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ51AHE3/5A?
SMAJ51AHE3/5A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ51AHE3/5A 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 SMAJ51AHE3/5A?
For technical support, including SMAJ51AHE3/5A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ51AHE3/5A requirements.
6.How does Aetrix verify that SMAJ51AHE3/5A is sourced from the original manufacturer or authorized distributors?
All SMAJ51AHE3/5A 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 SMAJ51AHE3/5A meets industry standards.
7.What is the process for return or replacement of SMAJ51AHE3/5A?
All SMAJ51AHE3/5A units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ51AHE3/5A, 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 SMAJ51AHE3/5A part is unused and in its original packaging.
Return procedure for SMAJ51AHE3/5A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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