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Vishay General Semiconductor - Diodes Division SMBJ78AHM3_A/H
- Part No.:
- SMBJ78AHM3_A/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ78AHM3_A/H.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:2,371
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Product details
Overview
SMBJ78AHM3_A/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 SMBJ78AHM3_A/H datasheet, SMBJ78AHM3_A/H pinout, SMBJ78AHM3_A/H application, or SMBJ78AHM3_A/H equivalent, key selection criteria include unidirectional polarity, halogen-free RoHS-compliant construction (HM3 suffix), AEC-Q101 qualification readiness, thermal resistance (RθJA = 100 °C/W), and junction temperature range of –55 °C to +150 °C.
Technical Context
This TVS diode operates as a voltage-clamping protection device triggered by overvoltage events such as inductive load switching or ESD. Its glass-passivated junction ensures stable breakdown behavior, while low incremental surge resistance enables effective energy diversion during transient events.
The SMBJ78AHM3_A/H is rated for 600 W peak pulse power (10/1000 µs), supports 100 A non-repetitive forward surge current (8.3 ms half-sine), and exhibits a temperature coefficient of VBR of 0.106 %/°C - critical for thermal stability in automotive and industrial environments where ambient temperatures exceed 85 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - maximum continuous reverse operating voltage before clamping begins |
| VBR (min/max) | 86.7 V / 95.8 V at 1 mA - guaranteed breakdown window defining turn-on threshold tolerance |
| VC @ IPPM | 126 V at 4.8 A - clamped voltage seen by protected circuit during full-rated transient |
| PPPM | 600 W - peak transient power absorption capability with standard 10/1000 µs waveform |
| IFSM | 100 A - surge current handling for 8.3 ms half-sine, supporting high-energy inductive kick protection |
| TJ max. | +150 °C - maximum junction temperature enabling operation in under-hood or enclosed industrial enclosures |
| RθJA | 100 °C/W - thermal resistance from junction to ambient on standard 0.2" × 0.2" copper pads |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, halogen-free, RoHS-compliant, MSL Level 1 (260 °C peak reflow). Cathode indicated by band marking on body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., ground or return path) in unidirectional configuration |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 78 V rail); band-marked end absorbs positive transients |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power (10/1000 µs) | Enables robust protection against IEC 61000-4-5 Level 4 surges without derating in typical PCB layouts |
| Glass passivated chip junction | Ensures long-term reliability and consistent VBR stability across temperature and lifetime cycling |
| Halogen-free, RoHS-compliant (HM3 suffix) | Meets environmental compliance requirements for automotive and industrial OEM production |
| AEC-Q101 qualification option | Supports automotive-grade sourcing paths via HM3_X suffix variants (e.g., SMBJ78AHM3_B/H) |
| Low profile SMB package | Reduces board space vs. SMA/SMB alternatives while maintaining 600 W rating and automated placement compatibility |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: Protecting 72–80 V DC input rails in programmable logic controller (PLC) power stages from load dump and relay coil flyback. IC Role / Device Role / Timing Role: Unidirectional clamping TVS placed between input rail and chassis ground to limit transient overvoltage to <126 V. Use Value: Prevents damage to upstream DC/DC controllers and downstream microcontrollers during 100 V/100 ms load dump events per ISO 16750-2. |
Use Scenario: Safeguarding LIN bus transceivers and power management ICs in BCMs exposed to battery voltage spikes during alternator regulation faults. IC Role / Device Role / Timing Role: Standoff-rated TVS on 12 V auxiliary supply rail, activated only during >78 V excursions. Use Value: Maintains functional safety integrity by limiting rail voltage to 126 V during 120 V/50 ms transients, preserving CAN/LIN communication uptime. |
| Telecom Remote Radio Unit (RRU) | Factory Automation Sensor Interface |
Use Scenario: Shielding RS-485 transceivers and bias networks in outdoor macrocell RRUs subjected to lightning-induced surges on DC power feeds. IC Role / Device Role / Timing Role: Primary clamping device on -48 V telecom supply line, coordinated with secondary GDT or MOV stages. Use Value: Clamps 600 W transients within 1 ns response time, preventing latch-up in isolated data interface ICs without adding capacitance penalties. |
Use Scenario: Protecting analog front-end amplifiers and ADC inputs in IO-Link sensors connected to 24 V industrial buses with frequent inductive switching noise. IC Role / Device Role / Timing Role: Localized TVS on sensor VDD rail, placed adjacent to connector entry point to minimize loop inductance. Use Value: Limits voltage overshoot to ≤126 V during 50 A/10 µs transients, preserving 16-bit ADC accuracy and avoiding reference rail corruption. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ78AHE3_A/H | RoHS-compliant but not halogen-free; lacks HM3 environmental certification | Acceptable for commercial-grade industrial use where halogen-free is not mandated | Select when cost sensitivity outweighs halogen-free requirement and AEC-Q101 is not needed |
| SMBJ78A-M3/5B | Same electrical specs; packaged in 13" reel (3200 pcs) vs. 7" reel (750 pcs) of SMBJ78AHM3_A/H | Optimized for high-volume SMT production with extended reel length and tape width | Choose for automated assembly lines requiring longer uninterrupted feed runs and reduced changeover frequency |
Compared with SMBJ78AHE3_A/H and SMBJ78A-M3/5B, the SMBJ78AHM3_A/H uniquely combines halogen-free construction, 7" reel packaging, and AEC-Q101-ready qualification - making it optimal for automotive-tier-2 suppliers and medical-grade power systems requiring full material compliance traceability.
Availability
SMBJ78AHM3_A/H is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, telecom remote radio units, and factory automation sensor interfaces requiring stable component supply with halogen-free and AEC-Q101-aligned sourcing options.
Supply support for SMBJ78AHM3_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, efficiency, and application-specific optimization.
The SMBJ series was developed to deliver high-power transient suppression in compact surface-mount packages for automotive, industrial, and telecom applications where space, thermal performance, and surge immunity are critical.
FAQ
What is the clamping voltage of SMBJ78AHM3_A/H at its rated peak pulse current?
The SMBJ78AHM3_A/H has a maximum clamping voltage (VC) of 126 V at its specified peak pulse current (IPPM) of 4.8 A, measured using the standard 10/1000 µs waveform. This value defines the upper voltage limit imposed on protected circuits during worst-case transient events, ensuring downstream components remain within safe operating limits. The SMBJ78AHM3_A/H maintains this clamping performance across its full operating temperature range.
Is SMBJ78AHM3_A/H qualified to AEC-Q101?
The SMBJ78AHM3_A/H is manufactured to AEC-Q101 qualification standards, as confirmed by Vishay's HM3 suffix designation indicating halogen-free, RoHS-compliant, and automotive-qualified construction. While the base part number does not embed "HE3" or "HM3_X", the "HM3" suffix in SMBJ78AHM3_A/H explicitly denotes AEC-Q101 readiness per Vishay's ordering nomenclature - verified in Document Number 88392, Revision 09-Jan-2024.
What does the "_A/H" suffix mean in SMBJ78AHM3_A/H?
In SMBJ78AHM3_A/H, the "_A/H" suffix indicates packaging configuration: "A" denotes revision level A per Vishay's internal documentation, and "H" specifies 7-inch diameter plastic tape-and-reel packaging containing 750 units. This matches Vishay's preferred package code "H" defined in the Ordering Information table (page 3 of document 88392), confirming standard commercial reel format and revision traceability.
Can SMBJ78AHM3_A/H be used in bidirectional applications?
No - SMBJ78AHM3_A/H is a unidirectional TVS diode, as indicated by its "A" suffix (vs. "CA" for bidirectional types like SMBJ78CA). Its cathode-band marking and asymmetric IV characteristics mean it conducts only in reverse bias above VBR; applying significant reverse voltage to the anode risks permanent damage. For bidirectional protection, select SMBJ78CA or equivalent CA-suffix variants.
What is the thermal resistance of SMBJ78AHM3_A/H, and how does it affect layout design?
The SMBJ78AHM3_A/H has a typical junction-to-ambient thermal resistance (RθJA) of 100 °C/W when mounted on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. This value assumes minimal copper area - designers must allocate adequate copper pour and thermal vias if operating near 5.0 W steady-state dissipation or in high-ambient environments (>70 °C) to avoid exceeding the +150 °C maximum junction temperature.
SMBJ78AHM3_A/H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AA, SMB
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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)
SMBJ78AHM3_A/H FAQ
1.How can I place an order for SMBJ78AHM3_A/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ78AHM3_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 SMBJ78AHM3_A/H reliable?
The price and inventory of SMBJ78AHM3_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 SMBJ78AHM3_A/H is usually 5 days.
3.What payment methods are accepted for SMBJ78AHM3_A/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ78AHM3_A/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ78AHM3_A/H?
SMBJ78AHM3_A/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ78AHM3_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 SMBJ78AHM3_A/H?
For technical support, including SMBJ78AHM3_A/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ78AHM3_A/H requirements.
6.How does Aetrix verify that SMBJ78AHM3_A/H is sourced from the original manufacturer or authorized distributors?
All SMBJ78AHM3_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 SMBJ78AHM3_A/H meets industry standards.
7.What is the process for return or replacement of SMBJ78AHM3_A/H?
All SMBJ78AHM3_A/H units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ78AHM3_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 SMBJ78AHM3_A/H part is unused and in its original packaging.
Return procedure for SMBJ78AHM3_A/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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