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Vishay General Semiconductor - Diodes Division SMAJ51-E3/5A
- Part No.:
- SMAJ51-E3/5A
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ51-E3/5A.pdf
- Description:
- TVS DIODE 51VWM 91.1VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,189
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Product details
Overview
SMAJ51-E3/5A from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for robust overvoltage protection of sensitive electronics. It features a 51 V standoff voltage (VWM), 56.7–69.3 V breakdown range (VBR at 1 mA), 91.1 V maximum clamping voltage (VC) at 4.4 A peak pulse current, and 400 W peak pulse power rating with 10/1000 µs waveform - suitable for protecting MOSFETs, ICs, and sensor signal lines against inductive switching transients and ESD.
For engineers reviewing the SMAJ51-E3/5A datasheet, SMAJ51-E3/5A pinout, SMAJ51-E3/5A application, or SMAJ51-E3/5A equivalent, this device delivers verified clamping performance, RoHS-compliant matte tin-plated leads, MSL Level 1 moisture sensitivity, and J-STD-002 solderability - critical for automotive-grade PCB assembly and high-reliability industrial power rail protection.
Technical Context
The SMAJ51-E3/5A operates as a unidirectional avalanche diode with cathode-band polarity marking, leveraging glass-passivated junction technology for stable breakdown and low incremental surge resistance. Its thermal design relies on 120 °C/W junction-to-ambient thermal resistance (RθJA) when mounted on 0.2 × 0.2" copper pads, enabling effective dissipation of 400 W transient energy without thermal runaway.
It complies with ANSI/IEEE C62.35 surge standards and supports repetitive surge duty cycles up to 0.01 %, with derating above 25 °C per Fig. 2. The device exhibits 1.0 µA maximum reverse leakage at VWM, ensuring minimal standby power loss in protected circuits such as 48 V DC power supplies and CAN bus interfaces.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous reverse operating voltage before clamping begins; defines safe working margin for 48 V nominal systems. |
| VBR (min/max) | 56.7 V / 69.3 V at 1 mA - Confirmed breakdown range ensures reliable turn-on during fast transients without premature conduction. |
| VC @ IPPM | 91.1 V at 4.4 A - Clamping voltage limits downstream component stress during 10/1000 µs surges, protecting 100 V-rated MOSFETs. |
| PPPM | 400 W - Peak pulse power handling capability enables suppression of high-energy transients like ISO 7637-2 Pulse 1/2a in automotive ECUs. |
| IFSM | 40 A - Surge current rating for 8.3 ms half-sine wave confirms compatibility with motor driver flyback energy absorption. |
| TJ Range | −55 °C to +150 °C - Extended junction temperature range supports under-hood automotive and industrial control cabinet deployment. |
| Package | DO-214AC (SMA) - Surface-mount outline with 0.208" body length and cathode band; optimized for automated pick-and-place and reflow. |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, RoHS-compliant, MSL Level 1, solderable per J-STD-002. Cathode identified by single black band on body end.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side connection point | Connected to ground or low-impedance return path; forms clamping loop with cathode during transient events. |
| Cathode (banded end) | High-side connection point | Connected to protected line (e.g., 48 V rail or signal trace); conducts avalanche current to shunt surge energy to ground. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR tolerance and long-term reliability under repeated surge stress without parameter drift. |
| 400 W peak pulse power (10/1000 µs) | Provides sufficient energy absorption for ISO 16750-2 automotive load dump pulses without failure. |
| Low incremental surge resistance | Minimizes VC overshoot during fast-rising transients (<1 ns), improving protection margin for high-speed logic. |
| MSL Level 1, 260 °C reflow compatible | Enables single-pass lead-free reflow assembly without popcorn cracking or delamination risk. |
| RoHS-compliant, JESD201 Class 1A whisker tested | Meets automotive electronics material compliance requirements including AEC-Q101 qualification for high-reliability use. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Signal Line Protection |
|---|---|
|
Use Scenario: Protecting 48 V battery-fed ECUs from load dump and alternator ripple transients per ISO 7637-2. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between power rail and chassis ground to clamp surges above 51 V. Use Value: Limits peak rail voltage to ≤91.1 V during 400 W transients, preventing damage to 100 V-rated DC-DC controllers and gate drivers. |
Use Scenario: Shielding analog output lines of pressure/temperature sensors in factory automation PLC modules. IC Role / Device Role / Timing Role: Low-capacitance (≈100 pF at 0 V) unidirectional clamp on 0–10 V or 4–20 mA signal paths. Use Value: Suppresses ESD and inductive kickback while maintaining signal integrity - leakage <1 µA avoids offset errors in precision ADC front-ends. |
| Telecom DC Power Input Protection | MOSFET Gate Driver Protection |
|
Use Scenario: Safeguarding -48 V telecom rectifier outputs against lightning-induced surges on central office equipment. IC Role / Device Role / Timing Role: Standoff-rated TVS connected anode-to-ground, cathode-to-input rail to absorb common-mode transients. Use Value: Withstands 40 A non-repetitive forward surge (IFSM) and clamps to 91.1 V, preserving -48 V system integrity during 10/1000 µs threats. |
Use Scenario: Preventing gate oxide rupture in high-side N-channel MOSFETs driven by microcontrollers in motor inverters. IC Role / Device Role / Timing Role: Clamp placed between gate and source to limit VGS excursion during Miller-induced voltage spikes. Use Value: Fast response time and 91.1 V clamping protect 100 V-rated gate oxides; DO-214AC footprint allows placement within 2 mm of gate pad. |
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 | Lower VBR range (56.7–62.7 V), tighter 10 % VWM/VBR ratio, 82.4 V clamping at 4.9 A. | Better suited for 48 V systems requiring lower clamping voltage and higher surge current margin. | Select SMAJ51A-E3/5A when tighter VBR tolerance and reduced VC are prioritized over absolute peak power rating. |
| SMBJ51A-E3/52 | Same VWM/VBR/VC specs but in larger DO-214AA (SMB) package; 600 W PPPM, RθJA = 80 °C/W. | Higher power handling and improved thermal performance for sustained surge environments. | Choose SMBJ51A-E3/52 where board space permits and thermal management demands exceed SMAJ51-E3/5A's 400 W capability. |
Compared with SMAJ51-E3/5A, the SMAJ51A-E3/5A offers lower clamping voltage and tighter breakdown control for precision 48 V rail protection, while the SMBJ51A-E3/52 provides superior thermal dissipation and 50 % higher peak power - making it preferable for high-duty-cycle industrial surge environments.
Availability
SMAJ51-E3/5A is available at Aetrix Electronics and suitable for automotive ECU power rail protection, industrial sensor interface hardening, and telecom DC input surge suppression requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for SMAJ51-E3/5A 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 high-reliability diodes, MOSFETs, and passive components for automotive, industrial, and computing markets.
The SMAJ series is engineered specifically for surface-mount transient voltage suppression in harsh environments - emphasizing robust clamping, AEC-Q101 qualification readiness, and automated assembly compatibility.
FAQ
What is the clamping voltage of SMAJ51-E3/5A under standard test conditions?
The SMAJ51-E3/5A has a maximum clamping voltage (VC) of 91.1 V at 4.4 A peak pulse current (IPPM) with a 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 and defines the upper voltage limit imposed on protected circuitry during surge events - critical for ensuring compatibility with 100 V-rated downstream components in the SMAJ51-E3/5A application.
Is SMAJ51-E3/5A RoHS compliant and qualified for automotive use?
Yes, SMAJ51-E3/5A carries the "E3" suffix indicating RoHS compliance per 2002/95/EC and meets JESD201 Class 1A whisker testing. While the base SMAJ51-E3/5A is commercial-grade, its construction - including glass-passivated junction, MSL Level 1 rating, and 150 °C TJ max - aligns with AEC-Q101 stress test requirements. For certified automotive grade, Vishay offers the HE3-suffixed variant (e.g., SMAJ51AHE3/5A).
What is the standoff voltage and why does it matter for SMAJ51-E3/5A?
The standoff voltage (VWM) of SMAJ51-E3/5A is 51 V - the maximum DC or continuous reverse voltage the device can withstand without entering avalanche conduction. This parameter ensures the SMAJ51-E3/5A remains non-conductive during normal operation of 48 V systems, avoiding leakage-related power loss or false triggering while providing headroom for transient suppression.
How does the DO-214AC (SMA) package affect thermal performance of SMAJ51-E3/5A?
The DO-214AC (SMA) package gives SMAJ51-E3/5A a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W when mounted on 0.2 × 0.2" copper pads. This thermal profile enables reliable 400 W transient dissipation in short bursts but requires careful PCB layout - including adequate copper area and thermal vias - to avoid exceeding the 150 °C maximum junction temperature during repetitive surges.
Can SMAJ51-E3/5A be used in bidirectional protection circuits?
No - SMAJ51-E3/5A is a unidirectional TVS diode, identifiable by its cathode band marking. For bidirectional protection, Vishay specifies CA-suffixed variants (e.g., SMAJ51CA-E3/5A), which exhibit symmetrical clamping in both polarities. Using SMAJ51-E3/5A in reverse-biased configurations risks permanent breakdown; always verify polarity alignment in the SMAJ51-E3/5A application schematic.
SMAJ51-E3/5A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AC, SMA
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 91.1V
- Current - Peak Pulse (10/1000µs):
- 4.4A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ51-E3/5A FAQ
1.How can I place an order for SMAJ51-E3/5A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ51-E3/5A 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 SMAJ51-E3/5A reliable?
The price and inventory of SMAJ51-E3/5A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ51-E3/5A is usually 5 days.
3.What payment methods are accepted for SMAJ51-E3/5A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ51-E3/5A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ51-E3/5A?
SMAJ51-E3/5A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ51-E3/5A 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 SMAJ51-E3/5A?
For technical support, including SMAJ51-E3/5A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ51-E3/5A requirements.
6.How does Aetrix verify that SMAJ51-E3/5A is sourced from the original manufacturer or authorized distributors?
All SMAJ51-E3/5A 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 SMAJ51-E3/5A meets industry standards.
7.What is the process for return or replacement of SMAJ51-E3/5A?
All SMAJ51-E3/5A units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ51-E3/5A, 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 SMAJ51-E3/5A part is unused and in its original packaging.
Return procedure for SMAJ51-E3/5A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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