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Diodes Incorporated SMBJ78A-13-F
- Part No.:
- SMBJ78A-13-F
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ78A-13-F.pdf
- Description:
- TVS DIODE 78VWM 126VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:10,560
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Product details
Overview
SMBJ78A-13-F from Diodes Incorporated is a unidirectional 600W surface-mount transient voltage suppressor (TVS) diode with 78V reverse standoff voltage, 86.7V minimum breakdown voltage at 1mA test current, and 126V maximum clamping voltage at 4.7A peak pulse current. It features glass-passivated die construction, SMB package, and is rated for industrial temperature range (–55°C to +150°C), used for overvoltage protection in DC power rails of industrial control modules.
For engineers reviewing the SMBJ78A-13-F datasheet, SMBJ78A-13-F pinout, SMBJ78A-13-F application, or SMBJ78A-13-F equivalent, key selection criteria include clamping voltage margin relative to protected IC VDD, peak pulse current capability under IEC 61000-4-5 surge conditions, standoff voltage alignment with nominal bus voltage, and SMB footprint compatibility with automated SMT assembly.
Technical Context
This TVS operates as a unidirectional avalanche clamp, triggered when reverse voltage exceeds VRWM = 78V and fully clamping at VC ≤ 126V under 4.7A 8.3ms half-sine surge. Its glass-passivated junction ensures stable leakage (<5µA at VRWM) and repeatable breakdown behavior across temperature.
The device is optimized for single-pulse transients per REA 10/1000µs waveform, with thermal derating of 4.8W/°C above +25°C ambient and steady-state power dissipation of 5.0W at TL = +75°C. It is not rated for repetitive surges beyond 4 pulses/minute.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 600W - sustains single 8.3ms surge without failure per IEC 61000-4-5 Level 4 compliance testing |
| Reverse Standoff Voltage | 78V - maximum continuous DC operating voltage before significant leakage begins |
| Breakdown Voltage | 86.7V min @ 1mA - guaranteed avalanche initiation threshold for reliable clamping onset |
| Clamping Voltage | 126V max @ 4.7A - limits voltage seen by downstream circuitry during worst-case surge event |
| Package | SMB - standardized 3.94 × 4.57 mm surface-mount outline compatible with IPC-7351B footprints |
| Operating Temperature | –55°C to +150°C - supports deployment in automotive engine compartments and industrial motor drives |
| Leakage Current | ≤5µA @ 78V - negligible standby power loss and no interference with high-impedance sensing nodes |
Pinout & Package
Package: SMB (Surface Mount Body), molded plastic case with UL 94V-0 flammability rating, matte tin-plated terminals, 0.1g mass.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Transient current sink node | Connected to protected line; conducts surge current to ground when reverse-biased beyond VRWM |
| Anode | Reference / return path | Typically tied to system ground or low-impedance return plane; completes clamping current path |
Key Features
| Feature | Design Value |
|---|---|
| 600W peak pulse rating | Enables robust protection against IEC 61000-4-5 4kV surge events on 24V/48V industrial buses |
| Glass-passivated die | Ensures long-term parameter stability and resistance to humidity-induced degradation in harsh environments |
| Lead-free & RoHS-compliant | Meets EU Directive 2011/65/EU and supports lead-free reflow profiles up to 260°C peak |
| SMB package footprint | Provides mechanical robustness and thermal performance superior to SMA while maintaining compact size |
| Low clamping ratio (VC/VRWM ≈ 1.61) | Minimizes overvoltage stress on protected ICs compared to higher-ratio TVS devices |
Applications
| Industrial PLC I/O Module Protection | 48V Telecom Power Supply Clamp |
|---|---|
Use Scenario: Protecting analog input channels and digital output drivers in programmable logic controllers exposed to field-wiring induced surges. IC Role / Device Role: Unidirectional TVS placed between signal line and ground to clamp fast transients before they reach precision ADCs or isolators. Use Value: Limits voltage excursion to ≤126V during 4.7A surge, preserving 24-bit ADC reference integrity and preventing latch-up in interface ICs. |
Use Scenario: Safeguarding primary-side controller ICs and secondary-side monitoring circuits in telecom rectifier modules. IC Role / Device Role: Clamping transient spikes on 48V DC distribution bus caused by hot-swap events or lightning-induced coupling. Use Value: Maintains bus voltage below 130V during 8.3ms surges, preventing overvoltage shutdown of PMICs and avoiding damage to optocoupler feedback paths. |
| Motor Drive Gate Driver Protection | Smart Energy Meter Surge Interface |
Use Scenario: Shielding isolated gate driver inputs from Miller-effect spikes and inductive kickback in 3-phase inverter stages. IC Role / Device Role: TVS mounted directly at gate driver supply pin (VDD) to suppress sub-100ns transients coupled through transformer parasitics. Use Value: Clamps 78V-rated rail to ≤126V within nanoseconds, ensuring gate driver IC remains within absolute maximum ratings during switching transitions. |
Use Scenario: Hardening RS-485 communication ports and AC voltage sensing inputs in utility-grade electricity meters deployed in outdoor substations. IC Role / Device Role: Front-end transient suppression on meter's auxiliary power input and data line interfaces subject to indirect lightning surges. Use Value: Withstands 600W pulses without degradation, enabling compliance with IEC 61000-4-5 Ed.3 Class 3 immunity requirements for smart grid infrastructure. |
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 (Vishay) | Same 78V VRWM, 126V VC, but rated for 1000W peak pulse power and uses different die process | Higher energy handling enables use in higher-inductance circuits where longer surge duration occurs | Select when surge test profile exceeds 600W or when extended lifetime under repeated stress is required |
| 1.5SMC78A (ON Semiconductor) | Identical electrical specs but in larger SMC package (7.11 × 6.22 mm); 10% higher thermal resistance | Lower power density limits placement near heat-sensitive components; requires more PCB area | Choose only if existing SMC footprint is fixed and no redesign is permitted |
Compared with SMBJ78A-13-F, the Vishay SMBJ78A-E3/52 offers higher surge margin for demanding industrial environments, while the ON Semiconductor 1.5SMC78A trades compact SMB size for easier manual handling and legacy board compatibility-neither is pin-compatible due to differing package outlines.
Availability
SMBJ78A-13-F is available at Aetrix Electronics and suitable for industrial automation systems, telecom power supplies, motor drive subsystems, and smart metering platforms requiring stable component supply and full traceability.
Supply support for SMBJ78A-13-F 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design centers across Asia and manufacturing facilities in China, Malaysia, and Taiwan.
The SMBJ series belongs to Diodes' transient voltage suppression product line, engineered specifically for high-reliability overvoltage protection in industrial, automotive, and communications equipment where compact size and precise clamping are critical.
FAQ
What is the polarity configuration of SMBJ78A-13-F?
SMBJ78A-13-F is a unidirectional TVS diode, indicated by the absence of "C" suffix (e.g., SMBJ78CA). It has a cathode band marking and conducts only when reverse-biased, making it suitable for DC rail protection where polarity is fixed. It does not conduct in forward bias except at typical silicon diode forward voltage (~3.5V).
Can SMBJ78A-13-F be used in AC line protection?
No - SMBJ78A-13-F is unidirectional and unsuitable for AC line protection. For bidirectional AC applications, the bi-directional variant SMBJ78CA must be used. Using SMBJ78A on AC would result in forward conduction during alternate half-cycles, causing overheating and failure.
What is the maximum allowable PCB trace length between SMBJ78A-13-F and protected IC?
To maintain effective clamping, the combined trace inductance from TVS cathode to protected node and anode to ground plane must remain below ~10nH. This typically limits total trace length to ≤15mm with tight ground coupling. Longer traces increase clamping voltage overshoot and reduce protection efficacy.
Does SMBJ78A-13-F require derating at elevated ambient temperatures?
Yes - its peak pulse power must be linearly derated above +25°C at 4.8W/°C, and steady-state power dissipation drops to 5.0W only at TL = +75°C. At +105°C ambient, peak pulse capability falls to ~240W, requiring system-level thermal analysis to ensure safe operation during surge events.
SMBJ78A-13-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJ
- Packaging:
- Tape & Reel (TR)
- 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):
- 4.7A
- Power - Peak Pulse:
- 600W
- 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:
- SMB
SMBJ78A-13-F FAQ
1.How can I place an order for SMBJ78A-13-F through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ78A-13-F 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 SMBJ78A-13-F reliable?
The price and inventory of SMBJ78A-13-F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ78A-13-F is usually 5 days.
3.What payment methods are accepted for SMBJ78A-13-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ78A-13-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ78A-13-F?
SMBJ78A-13-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ78A-13-F 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 SMBJ78A-13-F?
For technical support, including SMBJ78A-13-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ78A-13-F requirements.
6.How does Aetrix verify that SMBJ78A-13-F is sourced from the original manufacturer or authorized distributors?
All SMBJ78A-13-F 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 SMBJ78A-13-F meets industry standards.
7.What is the process for return or replacement of SMBJ78A-13-F?
All SMBJ78A-13-F units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ78A-13-F, 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 SMBJ78A-13-F part is unused and in its original packaging.
Return procedure for SMBJ78A-13-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ78A-13-F Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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onsemi
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Diodes Incorporated
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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