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Vishay General Semiconductor - Diodes Division SMAJ51CA-E3/61
- Part No.:
- SMAJ51CA-E3/61
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ51CA-E3/61.pdf
- Description:
- TVS DIODE 51VWM 82.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:8,710
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Product details
Overview
SMAJ51CA-E3/61 from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode designed for robust overvoltage protection of sensitive electronics. It features a 51 V standoff voltage (VWM), 56.7–62.7 V breakdown range (VBR), and clamps transients to ≤82.4 V at 4.9 A peak pulse current (IPPM), delivering 400 W peak pulse power (10/1000 μs waveform) in the SMA (DO-214AC) package. It is widely deployed to protect MOSFETs, ICs, and sensor signal lines against inductive switching surges and lightning-induced transients in industrial and automotive systems.
For engineers reviewing the SMAJ51CA-E3/61 datasheet, SMAJ51CA-E3/61 pinout, SMAJ51CA-E3/61 application, or SMAJ51CA-E3/61 equivalent, key selection criteria include bidirectional clamping symmetry, low clamping ratio (VC/VWM ≈ 1.62), MSL Level 1 moisture sensitivity, and AEC-Q101 qualification eligibility via HE3 suffix variants - all critical for high-reliability board-level surge protection design.
Technical Context
This device operates as a voltage-clamped crowbar during transient events: when reverse (or forward, in bidirectional mode) voltage exceeds VBR, it avalanches into low-impedance conduction, diverting surge current away from protected circuitry. Its glass-passivated junction ensures stable breakdown characteristics and fast response (<1 ps), while the unidirectional/bidirectional dual capability enables flexible placement on AC-coupled or differential signal paths.
The SMAJ51CA-E3/61 exhibits a temperature coefficient of VBR of +0.104 %/°C and thermal resistance of 120 °C/W (junction-to-ambient), requiring careful PCB copper pad design (0.2" × 0.2") to sustain its 400 W rating. It complies with ANSI/IEEE C62.35 and UL 497B (QVGQ2 recognition), supporting safety-certified designs without external coordination components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC/AC signal swing margin. |
| VBR (min/max) | 56.7 V / 62.7 V at 1 mA - Ensures reliable avalanche initiation across process and temperature variation. |
| VC @ IPPM | ≤82.4 V at 4.9 A - Clamping voltage under 10/1000 μs surge; determines maximum stress on downstream ICs. |
| PPPM | 400 W (10/1000 μs) - Peak transient energy handling capacity; derates to 300 W above 78 V per spec. |
| IFSM | 40 A - Non-repetitive forward surge rating (8.3 ms half-sine); supports rare fault-current events. |
| TJmax | +150 °C - Maximum junction temperature; enables operation in under-hood automotive or industrial enclosures. |
| RθJA | 120 °C/W - Thermal resistance with standard pad layout; dictates minimum copper area needed for thermal management. |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, low-profile plastic case with matte tin-plated leads; meets UL 94 V-0 and J-STD-020 MSL Level 1 (peak reflow 260 °C).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked end) | Not applicable - bidirectional device | No polarity marking; terminals are symmetrical; either lead may connect to line or return in AC/differential applications. |
| Anode | Not applicable - bidirectional device | Identical electrical behavior in both directions; no cathode band; device functions identically regardless of orientation. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC signals, differential buses (e.g., RS-485), or floating sensor inputs without polarity concerns. |
| 400 W peak pulse power (10/1000 μs) | Provides robust immunity to IEC 61000-4-5 Level 3/4 surges (e.g., 2 kV line-earth) when properly mounted on 5 mm × 5 mm copper pads. |
| Low clamping ratio (VC/VWM = 1.62) | Minimizes voltage overshoot during clamping, reducing risk of latch-up or gate oxide damage in protected MOSFETs and logic ICs. |
| MSL Level 1, 260 °C peak reflow | Supports standard lead-free SMT assembly without baking or special handling; compatible with high-volume automated placement. |
| AEC-Q101 qualification path | HE3/HM3 suffix variants are automotive-qualified; this E3/61 version shares identical die and construction, enabling qualification traceability. |
Applications
| Industrial Motor Control | Automotive Body Electronics |
|---|---|
|
Use Scenario: Protection of gate drivers and microcontroller I/O pins from inductive kickback during relay or solenoid switching in PLCs and motor drives. IC Role / Device Role / Timing Role: Bidirectional TVS placed across power rails or signal lines to clamp sub-100 ns transients before they reach sensitive CMOS inputs. Use Value: Prevents cumulative degradation and immediate failure of 3.3 V/5 V logic interfaces exposed to >100 V spikes, extending system MTBF in harsh factory environments. |
Use Scenario: Shielding LIN bus transceivers and door module sensors from load dump and jump-start surges in 12 V vehicle networks. IC Role / Device Role / Timing Role: Standoff-rated clamping element absorbing repetitive 10/1000 μs pulses up to 400 W without parameter drift. Use Value: Maintains signal integrity on bidirectional LIN lines during battery voltage excursions (e.g., 24 V jump-start), avoiding communication timeouts or false triggers. |
| Consumer Power Adapters | Telecom Interface Protection |
|
Use Scenario: Safeguarding secondary-side feedback optocouplers and synchronous rectifier controllers in USB-C PD adapters against AC line transients. IC Role / Device Role / Timing Role: Fast-response shunt protector across isolated control signal paths, activated within picoseconds of overvoltage onset. Use Value: Eliminates need for series impedance or RC filtering, preserving tight regulation loop bandwidth while meeting UL 62368-1 surge requirements. |
Use Scenario: Protecting Ethernet PHY magnetics and PoE controller inputs from lightning-induced common-mode surges on outdoor telecom links. IC Role / Device Role / Timing Role: Primary-stage TVS on transformer center taps or data line pairs, working in concert with GDTs for staged protection. Use Value: Limits let-through voltage to <85 V, ensuring PoE IEEE 802.3af/at compliance and preventing damage to 2.5 V/3.3 V PHY analog front-ends. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ51CA | Same VWM/VC specs but in larger SMB (DO-214AA) package; 600 W PPPM; RθJA = 80 °C/W. | Higher power handling and better thermal performance, but requires 30% more PCB area; suited for higher-energy surge environments. | Select SMBJ51CA when surge duty cycle or ambient temperature demands lower thermal resistance and higher pulse margin. |
| SMCJ51CA | Same VWM/VC but in SMC (DO-214AB) package; 1500 W PPPM; RθJA = 35 °C/W; larger footprint and height. | Designed for severe industrial or telecom primary protection; overkill for board-level secondary protection unless extreme surge levels apply. | Choose SMCJ51CA only when IEC 61000-4-5 Level 4 (4 kV) or lightning test compliance is mandatory and space permits. |
Compared with SMBJ51CA and SMCJ51CA, the SMAJ51CA-E3/61 delivers optimal balance of compact size, 400 W surge capability, and automated assembly compatibility - making it the preferred choice for space-constrained, high-volume consumer and industrial PCBs where moderate surge immunity suffices.
Availability
SMAJ51CA-E3/61 is available at Aetrix Electronics and suitable for industrial motor control, automotive body electronics, and consumer power adapter designs requiring stable component supply, RoHS-compliant commercial-grade TVS diodes with verified surge performance and MSL Level 1 reflow compatibility.
Supply support for SMAJ51CA-E3/61 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, precision, and application-specific optimization.
The SMAJ series is engineered for surface-mount transient suppression in cost-sensitive, high-volume applications - prioritizing fast response, consistent clamping, and compatibility with automated manufacturing while meeting industrial and automotive stress standards.
FAQ
What is the clamping voltage of the SMAJ51CA-E3/61 under a 10/1000 μs surge?
The SMAJ51CA-E3/61 clamps to a maximum of 82.4 V when subjected to its rated peak pulse current of 4.9 A (10/1000 μs waveform). This value is measured per ANSI/IEEE C62.35 and confirmed in Vishay's datasheet revision 09-Jan-2024, Document Number 88390. The clamping voltage directly determines the maximum stress imposed on downstream components during transient events, making it a critical parameter for interface protection design using the SMAJ51CA-E3/61.
Is SMAJ51CA-E3/61 suitable for automotive applications?
The SMAJ51CA-E3/61 itself is a commercial-grade RoHS-compliant part (E3 suffix), but it shares identical die, construction, and testing methodology with the AEC-Q101 qualified SMAJ51CAHE3 variant. While SMAJ51CA-E3/61 is not certified, its design lineage and qualification path enable straightforward automotive qualification for customers needing AEC-Q101 compliance - many Tier 1 suppliers use E3 versions for pre-qualification prototyping before transitioning to HE3 suffix parts in final production.
How does the bidirectional nature of SMAJ51CA-E3/61 affect PCB layout?
The SMAJ51CA-E3/61 has no polarity marking and identical electrical behavior in both directions, eliminating orientation constraints during placement. This simplifies layout for AC-coupled lines, differential buses (e.g., CAN, RS-485), or floating sensor inputs - unlike unidirectional TVS diodes, no cathode/anode alignment is required. Engineers can route either terminal to signal or reference without affecting clamping performance, reducing assembly errors and enabling denser routing in constrained layouts using the SMAJ51CA-E3/61.
What is the maximum operating temperature for SMAJ51CA-E3/61?
The SMAJ51CA-E3/61 has a maximum junction temperature (TJmax) of +150 °C and an operating junction/storage temperature range of –55 °C to +150 °C. Its thermal resistance (RθJA) is 120 °C/W under standard mounting conditions (0.2" × 0.2" copper pads), meaning sustained power dissipation must be limited to avoid exceeding TJmax. This rating allows reliable deployment in under-hood automotive modules, industrial drives, and enclosed power supplies where ambient temperatures exceed 85 °C - a key design advantage of the SMAJ51CA-E3/61.
Does SMAJ51CA-E3/61 require external series impedance for effective protection?
No, the SMAJ51CA-E3/61 functions as a shunt protector and does not require external series impedance to operate. Its sub-nanosecond response time and low dynamic impedance allow it to clamp transients before downstream components experience damaging overvoltage. However, adding small series resistance or ferrite beads upstream can reduce di/dt stress and improve energy sharing in multi-stage protection schemes - but such elements are optional enhancements, not functional prerequisites for the SMAJ51CA-E3/61 to deliver specified clamping performance.
SMAJ51CA-E3/61 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:
- -
- Bidirectional Channels:
- 1
- 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:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ51CA-E3/61 FAQ
1.How can I place an order for SMAJ51CA-E3/61 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ51CA-E3/61 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 SMAJ51CA-E3/61 reliable?
The price and inventory of SMAJ51CA-E3/61 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ51CA-E3/61 is usually 5 days.
3.What payment methods are accepted for SMAJ51CA-E3/61?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ51CA-E3/61 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ51CA-E3/61?
SMAJ51CA-E3/61 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ51CA-E3/61 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 SMAJ51CA-E3/61?
For technical support, including SMAJ51CA-E3/61 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ51CA-E3/61 requirements.
6.How does Aetrix verify that SMAJ51CA-E3/61 is sourced from the original manufacturer or authorized distributors?
All SMAJ51CA-E3/61 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 SMAJ51CA-E3/61 meets industry standards.
7.What is the process for return or replacement of SMAJ51CA-E3/61?
All SMAJ51CA-E3/61 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ51CA-E3/61, 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 SMAJ51CA-E3/61 part is unused and in its original packaging.
Return procedure for SMAJ51CA-E3/61:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ51CA-E3/61 Tags
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