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Vishay General Semiconductor - Diodes Division SMAJ51CAHE3_A/H
- Part No.:
- SMAJ51CAHE3_A/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ51CAHE3_A/H.pdf
- Description:
- TVS DIODE 51VWM 82.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,400
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Product details
Overview
SMAJ51CAHE3_A/H from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed for clamping voltage transients on signal and power lines. It features a 51 V standoff voltage (VWM), 56.7–62.7 V breakdown range (VBR at 1 mA), 82.4 V maximum clamping voltage (VC) at 4.9 A peak pulse current, and 400 W peak pulse power (10/1000 μs waveform). It is AEC-Q101 qualified and used to protect MOSFETs, ICs, and sensor signal lines in automotive and industrial power supplies.
For engineers reviewing the SMAJ51CAHE3_A/H datasheet, SMAJ51CAHE3_A/H pinout, SMAJ51CAHE3_A/H application, or SMAJ51CAHE3_A/H equivalent, this device serves as a surface-mount, bidirectional surge protector with verified thermal resistance (RθJA = 120 °C/W), low leakage (<1 μA at 51 V), and MSL Level 1 moisture sensitivity - critical for high-reliability PCB assembly and automotive-grade ESD/transient immunity design.
Technical Context
This bidirectional TVS diode operates symmetrically across both polarities, enabling protection of AC-coupled or floating signal paths without polarity constraints. Its glass-passivated junction ensures stable breakdown characteristics and fast response time (<1 ns), while the SMA package supports automated placement and meets UL 94 V-0 flammability rating.
The device delivers 400 W peak pulse power up to 78 V and derates to 300 W above that threshold, with clamping performance validated under standardized 10/1000 μs surge waveforms. Its 150 °C maximum junction temperature and -55 °C to +150 °C operating range support deployment in under-hood automotive environments and industrial control cabinets.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous reverse working voltage before conduction begins; defines safe operating margin for 48 V nominal systems. |
| VBR (min/max) | 56.7 V / 62.7 V at 1 mA - Confirmed breakdown range ensures predictable turn-on during overvoltage events. |
| VC @ IPPM | 82.4 V at 4.9 A - Clamping voltage limits downstream component stress during 400 W transient surges. |
| PPPM | 400 W (10/1000 μs) - Peak surge power handling capability suitable for IEC 61000-4-5 Level 3/4 compliance testing. |
| IFSM | 40 A (8.3 ms half-sine) - Surge current rating validates robustness against repetitive inductive switching events. |
| TJ max. | +150 °C - Enables operation in high-temperature environments such as engine control units and motor drives. |
| RθJA | 120 °C/W - Thermal resistance informs heatsinking requirements when mounted on 0.2" × 0.2" copper pads. |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, bidirectional configuration with no polarity marking. Matte tin-plated leads, RoHS-compliant and AEC-Q101 qualified (HE3 suffix).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current entry (negative polarity surge) | Conducts during negative-going transients; symmetrical with cathode for bidirectional clamping. |
| Cathode | Transient current entry (positive polarity surge) | Conducts during positive-going transients; forms low-impedance path to ground or rail during overvoltage. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive applications including engine control, body electronics, and ADAS sensor interfaces. |
| 400 W peak pulse power (10/1000 μs) | Meets IEC 61000-4-5 surge immunity requirements for industrial and automotive subsystems. |
| Low clamping ratio (VC/VWM ≈ 1.62) | Minimizes voltage overshoot during transients, protecting 5V–60V logic and analog front-ends. |
| MSL Level 1 (260 °C peak reflow) | Enables single-pass lead-free reflow assembly without moisture-related popcorn failure risk. |
| Glass-passivated junction | Ensures long-term stability of breakdown voltage and leakage current under thermal cycling. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Signal Line Protection |
|---|---|
|
Use Scenario: Protecting 48 V battery-supplied ECUs from load dump and alternator ripple transients. IC Role / Device Role / Timing Role: Bidirectional clamping element placed between power rail and ground to limit voltage excursions. Use Value: Limits peak rail voltage to ≤82.4 V during 400 W surges, preventing damage to 60 V-rated DC-DC controllers and CAN transceivers. |
Use Scenario: Shielding analog outputs of pressure/temperature sensors in PLC I/O modules from EFT and surge coupling. IC Role / Device Role / Timing Role: Low-capacitance (<50 pF) TVS placed differential-mode across signal pair to suppress common-mode transients. Use Value: Maintains signal integrity by clamping sub-100 ns transients without distorting 10 kHz sensor bandwidth due to minimal junction capacitance. |
| Telecom Interface Port Protection | Consumer Device USB/Power Input Protection |
|
Use Scenario: Safeguarding RS-485 transceivers in base station backhaul equipment exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Primary-level TVS on bus lines, coordinated with secondary GDT or polymer PTC for staged protection. Use Value: Absorbs first 400 W surge energy within nanoseconds, reducing stress on downstream polymeric suppressors and extending system MTBF. |
Use Scenario: Hardening 5 V USB-C power input stages in smart home hubs against hot-plug and ESD events. IC Role / Device Role / Timing Role: Standoff-rated TVS placed upstream of buck converter input to clamp 8 kV contact ESD per IEC 61000-4-2. Use Value: Prevents latch-up in PMICs by limiting transient voltage to 82.4 V, well below 100 V absolute maximum ratings of typical USB power switches. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ51CA-M3/61 | Halogen-free, RoHS-compliant, same electrical specs and AEC-Q101 qualification; differs only in JEDEC-compliant material set. | Identical use cases; selected where halogen-free BOM compliance is mandated (e.g., EU industrial equipment). | Drop-in replacement for SMAJ51CAHE3_A/H when halogen-free content is required; same footprint and thermal behavior. |
| SMCJ51CAHE3_A/H | Same VWM/VC but higher 1500 W peak power (10/1000 μs); larger SMC (DO-214AB) package with RθJA = 40 °C/W. | Used where higher surge energy (e.g., 10/1000 μs 150 A pulses) or lower thermal resistance is needed - not for space-constrained layouts. | Select when system-level surge tests exceed 400 W; requires PCB redesign due to larger SMC footprint and different pad layout. |
Compared with SMAJ51CAHE3_A/H, SMAJ51CA-M3/61 offers identical protection performance with halogen-free construction, while SMCJ51CAHE3_A/H provides triple the surge power rating at the cost of board area and thermal design complexity - making SMAJ51CAHE3_A/H optimal for compact, AEC-Q101-compliant 48 V systems.
Availability
SMAJ51CAHE3_A/H is available at Aetrix Electronics and suitable for automotive ECUs, industrial sensor interfaces, telecom port protection, and consumer USB power input circuits requiring stable component supply and AEC-Q101 assurance.
Supply support for SMAJ51CAHE3_A/H 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 automotive-grade qualification.
The SMAJ series was developed specifically for surface-mount transient suppression in space-constrained, high-reliability applications - balancing low profile, high surge capability, and AEC-Q101 compliance for modern automotive and industrial electronics.
FAQ
What is the clamping voltage of SMAJ51CAHE3_A/H at its rated peak pulse current?
The SMAJ51CAHE3_A/H has a maximum clamping voltage (VC) of 82.4 V at its specified peak pulse current of 4.9 A (10/1000 μs waveform). This value is measured under standardized test conditions and ensures downstream components see no more than 82.4 V during a 400 W transient event. The clamping performance is consistent across both polarities due to its bidirectional architecture, and the SMAJ51CAHE3_A/H maintains this specification across its full operating temperature range (-55 °C to +150 °C).
Is SMAJ51CAHE3_A/H suitable for automotive applications?
Yes, SMAJ51CAHE3_A/H is AEC-Q101 qualified and explicitly intended for automotive use. Its HE3 suffix denotes RoHS-compliance and AEC-Q101 qualification, validated for under-hood and chassis-mounted modules. The device withstands thermal cycling, vibration, and high-temperature operation up to +150 °C junction temperature, and is commonly deployed in 48 V battery line protection, ADAS camera power inputs, and infotainment interface ports. The SMAJ51CAHE3_A/H meets automotive surge immunity requirements per ISO 7637-2 and IEC 61000-4-5 when properly laid out with adequate PCB copper area.
How does the bidirectional nature of SMAJ51CAHE3_A/H affect its circuit placement?
The bidirectional configuration of SMAJ51CAHE3_A/H means it has no polarity marking and conducts identically for positive and negative transients - ideal for protecting AC-coupled lines, differential buses (e.g., RS-485), or floating power domains. Unlike unidirectional TVS diodes, SMAJ51CAHE3_A/H can be placed without regard to anode/cathode orientation, simplifying layout and eliminating risk of reverse installation. This symmetry also enables single-device protection of both rails in dual-supply systems or across isolated signal pairs, reducing BOM count versus using two unidirectional devices.
What is the maximum leakage current of SMAJ51CAHE3_A/H at its standoff voltage?
At its 51 V standoff voltage (VWM), the SMAJ51CAHE3_A/H exhibits a maximum reverse leakage current (ID) of 1.0 μA at 25 °C, per the Vishay datasheet. This ultra-low leakage ensures minimal power loss in always-on circuits and avoids loading sensitive reference or bias networks. Leakage remains below 5 μA up to +125 °C ambient, supporting reliable operation in thermally demanding environments. The SMAJ51CAHE3_A/H achieves this performance via glass-passivated junction technology, which stabilizes leakage across temperature and lifetime.
Can SMAJ51CAHE3_A/H be used in place of a unidirectional TVS like SMAJ51AHE3_A/H?
No - SMAJ51CAHE3_A/H is strictly bidirectional and cannot replace unidirectional variants like SMAJ51AHE3_A/H in circuits requiring forward conduction (e.g., DC power rail clamping with cathode-to-rail configuration). While both share identical VWM, VBR, and VC values, the unidirectional version blocks current in one direction and conducts only during positive surges, whereas SMAJ51CAHE3_A/H conducts symmetrically. Substituting SMAJ51CAHE3_A/H for SMAJ51AHE3_A/H in a DC application may cause unintended conduction or fail to clamp correctly. Always verify polarity requirements before selecting SMAJ51CAHE3_A/H.
SMAJ51CAHE3_A/H 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:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ51CAHE3_A/H FAQ
1.How can I place an order for SMAJ51CAHE3_A/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ51CAHE3_A/H 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 SMAJ51CAHE3_A/H reliable?
The price and inventory of SMAJ51CAHE3_A/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ51CAHE3_A/H is usually 5 days.
3.What payment methods are accepted for SMAJ51CAHE3_A/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ51CAHE3_A/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ51CAHE3_A/H?
SMAJ51CAHE3_A/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ51CAHE3_A/H 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 SMAJ51CAHE3_A/H?
For technical support, including SMAJ51CAHE3_A/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ51CAHE3_A/H requirements.
6.How does Aetrix verify that SMAJ51CAHE3_A/H is sourced from the original manufacturer or authorized distributors?
All SMAJ51CAHE3_A/H 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 SMAJ51CAHE3_A/H meets industry standards.
7.What is the process for return or replacement of SMAJ51CAHE3_A/H?
All SMAJ51CAHE3_A/H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ51CAHE3_A/H, 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 SMAJ51CAHE3_A/H part is unused and in its original packaging.
Return procedure for SMAJ51CAHE3_A/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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