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Vishay General Semiconductor - Diodes Division SMBJ78AHE3_B/H
- Part No.:
- SMBJ78AHE3_B/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ78AHE3_B/H.pdf
- Description:
- 600W,78V 5%,UNIDIR,SMB TVS
- Quantity:
- Payment:
- Shipping:
Inventory:9,889
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Product details
Overview
SMBJ78AHE3_B/H from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, designed for clamping voltage transients on power and signal lines. It features a 78 V stand-off voltage (VWM), 86.7–95.8 V breakdown voltage (VBR) at 1 mA, 126 V maximum clamping voltage (VC) at 4.8 A peak pulse current, and 600 W peak pulse power rating with 10/1000 µs waveform - used to protect MOSFETs, ICs, and sensor interfaces in industrial power supplies.
For engineers reviewing the SMBJ78AHE3_B/H datasheet, SMBJ78AHE3_B/H pinout, SMBJ78AHE3_B/H application, or SMBJ78AHE3_B/H equivalent, this device is evaluated for overvoltage protection in DC power rails, automotive body electronics, and telecom interface circuits where fast response (<1 ps), low clamping ratio (VC/VWM ≈ 1.61), and AEC-Q101 qualification are critical selection criteria.
Technical Context
This TVS diode operates as a unidirectional avalanche clamp, conducting only during reverse overvoltage events while presenting high impedance under normal bias. Its glass-passivated junction ensures stable breakdown characteristics and low leakage (<1 µA at 78 V), and its thermal resistance (RθJA = 100 °C/W) supports operation up to +150 °C junction temperature.
The device complies with IEC 61000-4-2 (ESD), IEC 61000-4-4 (EFT), and ISO 7637-2 (automotive surge) immunity requirements when applied with proper PCB layout - including minimum 5.0 mm × 5.0 mm copper pads per terminal per Vishay's derating guidelines.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM (Stand-off Voltage) | 78 V - Maximum continuous reverse operating voltage before conduction begins; defines safe operating margin for 72–80 V DC rails. |
| VBR (Breakdown Voltage) | 86.7–95.8 V at 1 mA - Tight tolerance range ensures predictable turn-on across production lots and temperature. |
| VC (Clamping Voltage) | 126 V at 4.8 A (10/1000 µs) - Limits downstream voltage stress to ≤126 V during surge, protecting 100 V-rated components. |
| PPPM (Peak Pulse Power) | 600 W - Sustains 10/1000 µs surges without degradation; derates linearly above 25 °C ambient per Fig. 2. |
| IPPM (Peak Pulse Current) | 4.8 A - Peak current handled at VC; correlates directly to surge energy absorption capability (≈0.3 J). |
| TJmax | +150 °C - Enables use in under-hood automotive and high-temperature industrial enclosures without thermal shutdown. |
| AEC-Q101 Qualified | Yes - Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per AEC specification. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, cathode-banded end. Dimensions: 4.57 mm × 3.94 mm × 2.20 mm (L × W × H); matte tin-plated leads, MSL Level 1, 260 °C reflow compatible.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current path / low-side reference | Connected to system ground or lower-potential rail; establishes reference for clamping action. |
| Cathode | Protected line input / high-side connection | Connected to line being protected (e.g., 78 V supply rail); conducts surge current to ground during overvoltage. |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power (10/1000 µs) | Enables robust protection against ISO 7637-2 Pulse 1/2a/5a surges in 12 V/24 V automotive systems without derating. |
| Low clamping ratio (VC/VWM = 1.61) | Minimizes overvoltage overshoot during clamping, reducing risk of latch-up or gate oxide damage in protected MOSFETs/ICs. |
| AEC-Q101 qualified (HE3 suffix) | Confirms long-term reliability for automotive applications including engine control units, body control modules, and ADAS sensors. |
| MSL Level 1, 260 °C reflow compatible | Supports standard lead-free SMT assembly without moisture sensitivity concerns or baking requirements. |
| Glass passivated junction | Ensures stable VBR over time and temperature, with <1 µA leakage at rated VWM, minimizing standby power loss. |
Applications
| Automotive Body Control Module (BCM) | Industrial 24 V DC Power Rail |
|---|---|
Use Scenario: Protects microcontroller I/O and CAN transceiver power pins from load dump and alternator ripple in BCMs. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between 24 V supply and ground, triggered within picoseconds during >35 V transients. Use Value: Limits voltage to ≤126 V during 100 V/50 ms load dump events, preventing reset or permanent damage to 3.3 V/5 V logic. |
Use Scenario: Shields programmable logic controllers (PLCs) and motor drivers from switching transients induced by contactor bounce or inductive kickback. IC Role / Device Role / Timing Role: Standoff-rated TVS on 24 V input rail, absorbing repetitive 600 W surges without degradation over 10+ years. Use Value: Maintains system uptime by eliminating field failures caused by transient-induced latch-up in isolated DC-DC converters. |
| Telecom Remote Radio Unit (RRU) | Consumer Smart Meter Power Input |
Use Scenario: Safeguards RF front-end bias lines and Ethernet PHY power against lightning-induced surges entering via outdoor cabling. IC Role / Device Role / Timing Role: Primary clamping device on +48 V PoE-derived rails, coordinated with upstream GDTs for staged protection. Use Value: Achieves IEC 61000-4-5 Level 3 (2 kV/12 Ω) surge immunity without sacrificing signal integrity on sensitive RF paths. |
Use Scenario: Guards metering SoC and real-time clock circuitry against ESD and capacitor discharge events during utility technician handling. IC Role / Device Role / Timing Role: Final-stage TVS on 3.3 V backup battery rail, activated only during human-contact ESD events (>8 kV contact). Use Value: Prevents data corruption or RTC reset by limiting transient duration to <1 ns and peak voltage to <126 V. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ78A-E3/52 | Commercial-grade (non-AEC-Q101), same VWM/VC/PPPM, identical SMB package and pinout. | Approved for industrial/commercial use only; not validated for automotive temperature cycling or lifetime reliability testing. | Select when cost sensitivity outweighs automotive qualification requirements and ambient temperature remains <125 °C. |
| SMCJ78AHE3_A/H | Same electrical specs but in larger SMC (DO-214AB) package; higher thermal mass (RθJA = 50 °C/W vs. 100 °C/W). | Better suited for high-repetition-rate surges or elevated ambient temperatures (>85 °C) due to superior heat dissipation. | Choose when board space permits and thermal management is prioritized over footprint minimization. |
Compared with SMBJ78AHE3_B/H, SMBJ78A-E3/52 offers identical protection performance at lower cost but lacks automotive qualification, while SMCJ78AHE3_A/H delivers enhanced thermal robustness in a larger footprint - enabling design flexibility across commercial, industrial, and automotive tiers without changing circuit topology.
Availability
SMBJ78AHE3_B/H is available at Aetrix Electronics and suitable for automotive body electronics, industrial 24 V power distribution, and telecom remote radio unit designs requiring stable component supply, AEC-Q101 compliance, and repeatable surge immunity performance.
Supply support for SMBJ78AHE3_B/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, precision, and application-specific validation.
The SMBJ series was developed specifically for high-energy transient suppression in space-constrained automotive and industrial environments, balancing low clamping voltage, fast response, and AEC-Q101 qualification in the compact SMB package.
FAQ
What is the maximum clamping voltage of SMBJ78AHE3_B/H at its rated peak pulse current?
The SMBJ78AHE3_B/H has a maximum clamping voltage (VC) of 126 V at 4.8 A peak pulse current (IPPM) under the standard 10/1000 µs waveform. This value is measured per IEC 61000-4-5 test conditions and defines the upper voltage limit imposed on protected circuitry during surge events. The SMBJ78AHE3_B/H maintains this clamping performance across its full operating temperature range (-55 °C to +150 °C) with minimal drift.
Is SMBJ78AHE3_B/H suitable for automotive applications?
Yes, SMBJ78AHE3_B/H is AEC-Q101 qualified, as confirmed by the "HE3" suffix and Vishay documentation (Doc. #88392, Rev. 09-Jan-2024). It undergoes rigorous stress testing including temperature cycling, high-temperature reverse bias, and ESD verification - making it suitable for under-hood and cabin applications such as body control modules, infotainment power rails, and ADAS sensor interfaces. The SMBJ78AHE3_B/H meets automotive-grade reliability requirements without derating at +125 °C ambient.
How does the SMBJ78AHE3_B/H differ from bidirectional variants like SMBJ78CA?
The SMBJ78AHE3_B/H is unidirectional and features a cathode band marking; it conducts only during reverse overvoltage events and blocks forward current beyond ~3.5 V. In contrast, SMBJ78CA is bidirectional with symmetrical clamping in both polarities and no polarity marking. The SMBJ78AHE3_B/H is selected for DC power rail protection where polarity is fixed, offering tighter VBR tolerance and lower leakage than bidirectional equivalents - critical for low-power standby circuits.
What is the thermal resistance of SMBJ78AHE3_B/H, and how does it affect layout?
The SMBJ78AHE3_B/H has a typical junction-to-ambient thermal resistance (RθJA) of 100 °C/W when mounted on 5.0 mm × 5.0 mm copper pads per terminal, as specified in Vishay's datasheet. This value requires adequate copper area and minimal trace length to maintain TJ ≤ 150 °C under worst-case 600 W surge duty cycles. Reducing pad size increases RθJA, risking thermal runaway - so PCB layout must follow Vishay's recommended mounting pad dimensions to ensure SMBJ78AHE3_B/H reliability.
Can SMBJ78AHE3_B/H be used in parallel for higher surge current handling?
No - SMBJ78AHE3_B/H is not recommended for parallel operation due to mismatched VBR tolerances (±5–10 %) causing current imbalance and premature failure of the lower-VBR unit. For higher surge ratings, select a single device with greater PPPM (e.g., SMCJ78AHE3_A/H) or cascade stages using GDTs and TVS diodes. The SMBJ78AHE3_B/H is characterized and qualified as a standalone clamp; parallel use voids AEC-Q101 validation and violates Vishay's application guidance.
SMBJ78AHE3_B/H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AA, SMB
- Series:
- TransZorb®
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 78V
- Voltage - Breakdown (Min):
- 86.7V
- Voltage - Clamping (Max) @ Ipp:
- 126V
- Current - Peak Pulse (10/1000µs):
- 4.8A
- Power - Peak Pulse:
- 600W
- 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-214AA (SMB)
SMBJ78AHE3_B/H FAQ
1.How can I place an order for SMBJ78AHE3_B/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ78AHE3_B/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 SMBJ78AHE3_B/H reliable?
The price and inventory of SMBJ78AHE3_B/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ78AHE3_B/H is usually 5 days.
3.What payment methods are accepted for SMBJ78AHE3_B/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ78AHE3_B/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ78AHE3_B/H?
SMBJ78AHE3_B/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ78AHE3_B/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 SMBJ78AHE3_B/H?
For technical support, including SMBJ78AHE3_B/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ78AHE3_B/H requirements.
6.How does Aetrix verify that SMBJ78AHE3_B/H is sourced from the original manufacturer or authorized distributors?
All SMBJ78AHE3_B/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 SMBJ78AHE3_B/H meets industry standards.
7.What is the process for return or replacement of SMBJ78AHE3_B/H?
All SMBJ78AHE3_B/H units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ78AHE3_B/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 SMBJ78AHE3_B/H part is unused and in its original packaging.
Return procedure for SMBJ78AHE3_B/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ78AHE3_B/H Tags
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