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Vishay General Semiconductor - Diodes Division SMBJ78AHM3_A/I
- Part No.:
- SMBJ78AHM3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ78AHM3_A/I.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:9,306
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Product details
Overview
SMBJ78AHM3_A/I from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMB (DO-214AA) package, designed for robust overvoltage protection of DC power rails 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 (IPPM), and 600 W peak pulse power rating with 10/1000 µs waveform - deployed in industrial motor drives, automotive body control modules, and telecom power supplies.
For engineers reviewing the SMBJ78AHM3_A/I datasheet, SMBJ78AHM3_A/I pinout, SMBJ78AHM3_A/I application, or SMBJ78AHM3_A/I equivalent, this page delivers verified electrical parameters, thermal derating behavior, AEC-Q101 qualification status, and direct replacement guidance for high-reliability transient suppression in 24 V–48 V systems.
Technical Context
This TVS diode operates as a unidirectional clamping device with cathode-banded polarity, leveraging a glass-passivated silicon junction to achieve sub-nanosecond response time and low incremental surge resistance. Its 126 V clamping voltage at 4.8 A ensures reliable protection of downstream MOSFETs and ICs during ISO 7637-2 pulse 1/2a/5a transients.
Rated for -55 °C to +150 °C junction temperature, it supports operation under high ambient conditions when mounted on 5.0 mm × 5.0 mm copper pads, with thermal resistance RθJA = 100 °C/W and RθJL = 20 °C/W - enabling predictable power dissipation up to 5.0 W at 50 °C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM (Stand-off Voltage) | 78 V - maximum continuous reverse voltage before significant leakage; sets operating margin above nominal 48 V rail. |
| VBR (Breakdown Voltage) | 86.7–95.8 V at 1 mA - defines onset of avalanche conduction; tight 10.5% tolerance enables precise overvoltage thresholding. |
| VC (Clamping Voltage) | 126 V at IPPM = 4.8 A - limits transient voltage seen by protected circuitry; critical for IEC 61000-4-5 Level 3 compliance. |
| PPPM (Peak Pulse Power) | 600 W with 10/1000 µs waveform - sustains high-energy surges without failure; validated per ANSI/IEEE C62.35. |
| ID (Reverse Leakage) | 1.0 µA max at VWM - ensures minimal standby power loss and no interference with high-impedance sensor bias networks. |
| TJ max. | +150 °C - supports under-hood automotive and industrial environments; enables use without active cooling. |
| AEC-Q101 Qualified | Yes - certified for automotive electronics per stress test requirements; ordering code suffix HM3 denotes halogen-free, RoHS-compliant, AEC-Q101 grade. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, low-profile case with matte tin-plated leads solderable per J-STD-002 and JESD 22-B102. Molding compound meets UL 94 V-0. Polarity indicated by cathode band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal during forward conduction; grounded side in standard unidirectional TVS configuration. | Connected to system ground or low-side return path; must be routed with low-inductance trace for effective surge shunting. |
| Cathode | Current exit terminal during reverse-biased clamping; connected to protected line (e.g., 48 V rail). | Band-marked end; ties directly to input of protected IC or MOSFET gate driver; determines clamping polarity and directionality. |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power (10/1000 µs) | Withstands repeated lightning-induced surges in industrial Ethernet ports and CAN FD bus nodes without degradation. |
| 126 V clamping at 4.8 A | Keeps protected 48 V microcontroller I/O pins below absolute maximum ratings during ISO 7637-2 pulse 5a (500 V/2 Ω). |
| AEC-Q101 qualified (HM3 suffix) | Validated for automotive body electronics including door modules and lighting controllers requiring zero-failure field reliability. |
| MSL Level 1 (260 °C peak reflow) | Enables single-pass lead-free reflow assembly without moisture-related popcorning or delamination. |
| Low incremental surge resistance | Minimizes voltage overshoot during fast-rising transients (<1 ns rise time), improving protection fidelity for high-speed logic interfaces. |
Applications
| Industrial Motor Drives | Automotive Body Control Modules |
|---|---|
|
Use Scenario: Protection of 48 V DC bus against inductive kickback from brushed DC motor commutation and relay coil de-energization. IC Role / Device Role / Timing Role: Unidirectional TVS placed between motor H-bridge supply rail and chassis ground to clamp negative-going transients. Use Value: Limits voltage excursions to ≤126 V, preventing gate oxide rupture in 60 V-rated N-channel MOSFETs and ensuring >100,000-cycle reliability. |
Use Scenario: Surge suppression on LIN bus power line and window lift actuator supply in passenger vehicle door modules. IC Role / Device Role / Timing Role: Standoff-rated TVS connected from 12 V battery feed to ground, activated only during load dump or jump-start events. Use Value: Survives 12 V system load dump (ISO 16750-2, 35 V/10 s) and clamps 1000 V/2 Ω transients to safe levels for 3.3 V MCU peripherals. |
| Telecom Power Supplies | Smart Building Sensor Networks |
|
Use Scenario: Input-stage protection of 48 V PoE-powered remote radio units exposed to outdoor lightning coupling. IC Role / Device Role / Timing Role: Primary clamping device upstream of DC/DC converter input, coordinated with upstream GDT and series impedance. Use Value: Absorbs 600 W surge energy while maintaining <1 µA leakage at 48 V, avoiding false triggering of OVP circuits. |
Use Scenario: Overvoltage safeguard for RS-485 transceivers and environmental sensors powered via 24 V daisy-chained wiring in HVAC ducts. IC Role / Device Role / Timing Role: Localized TVS at each node's power entry point, guarding against ESD and cable-coupled switching noise. Use Value: Provides <1 ns response to ±8 kV contact ESD (IEC 61000-4-2), preserving data integrity without adding capacitance to differential bus lines. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ78A | Same SMB package, 78 V VWM, but 135 V VC at 4.3 A; higher clamping voltage and lower IPPM (4.3 A vs. 4.8 A). | Marginally less effective clamping in 48 V systems near absolute maximum ratings; suitable where layout allows higher VC headroom. | Select if cost sensitivity outweighs 9 V clamping advantage and AEC-Q101 is not required. |
| ON Semiconductor SMCJ78A | Identical electrical specs (VWM = 78 V, VC = 126 V @ 4.8 A), but base P/N uses M3 suffix only - not AEC-Q101 qualified. | Lacks automotive qualification; acceptable for industrial/commercial use but requires separate validation for automotive Tier 1 programs. | Choose when AEC-Q101 is unnecessary and procurement prefers ON Semi's supply chain or logistics terms. |
Compared with SMAJ78A and SMCJ78A, SMBJ78AHM3_A/I delivers identical clamping performance plus AEC-Q101 qualification and halogen-free construction - making it the preferred choice for automotive and high-reliability industrial designs where certification and material compliance are mandatory.
Availability
SMBJ78AHM3_A/I is available at Aetrix Electronics and suitable for industrial motor drives, automotive body control modules, and telecom power supplies requiring stable component supply across multi-year production cycles.
Supply support for SMBJ78AHM3_A/I 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, and protection devices with emphasis on reliability, efficiency, and application-specific optimization.
The SMBJ series was engineered for high-power transient suppression in space-constrained surface-mount applications, targeting automotive, industrial, and telecom markets where robustness and qualification compliance are non-negotiable.
FAQ
What is the clamping voltage of SMBJ78AHM3_A/I at its rated peak pulse current?
The SMBJ78AHM3_A/I has a maximum clamping voltage (VC) of 126 V at its specified peak pulse current (IPPM) of 4.8 A with a 10/1000 µs waveform. This value is measured under standardized test conditions per ANSI/IEEE C62.35 and ensures predictable voltage limiting during surge events. The SMBJ78AHM3_A/I maintains this clamping performance across its full operating temperature range of -55 °C to +150 °C when properly mounted on recommended copper pad areas.
Is SMBJ78AHM3_A/I qualified for automotive applications?
Yes, SMBJ78AHM3_A/I is AEC-Q101 qualified, as confirmed by its HM3 suffix and documentation in Vishay's official datasheet (Document Number: 88392, Revision: 09-Jan-2024). The HM3 designation indicates halogen-free, RoHS-compliant construction combined with full AEC-Q101 stress testing - making SMBJ78AHM3_A/I suitable for automotive body electronics, infotainment power rails, and other non-safety-critical vehicle subsystems.
What does the "_A/I" suffix mean in SMBJ78AHM3_A/I?
The "_A/I" suffix in SMBJ78AHM3_A/I specifies packaging and reel configuration: "A" denotes the revision code (Revision A per Vishay's ordering nomenclature), and "I" indicates 13-inch diameter plastic tape and reel packaging with a base quantity of 3200 units. This format aligns with Vishay's standard delivery mode for high-volume automated assembly and is distinct from the "H" (7-inch reel, 750 units) variant.
How does SMBJ78AHM3_A/I differ from bidirectional variants like SMBJ78CA?
SMBJ78AHM3_A/I is unidirectional, with polarity marked by a cathode band and intended for DC rail protection where reverse conduction must be blocked. In contrast, SMBJ78CA is bidirectional, offering symmetrical clamping for AC or floating signal lines - but lacks a polarity marker and exhibits doubled ID limit for VWM ≤10 V (not applicable here). SMBJ78AHM3_A/I provides lower leakage and tighter VBR tolerance than its bidirectional counterpart at equivalent VWM.
What is the thermal resistance of SMBJ78AHM3_A/I, and how does it affect layout design?
SMBJ78AHM3_A/I has a typical junction-to-ambient thermal resistance (RθJA) of 100 °C/W and junction-to-lead resistance (RθJL) of 20 °C/W, measured on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. To maintain safe junction temperatures, PCB layout must allocate adequate copper area and avoid thermal bottlenecks - especially critical when operating near its 5.0 W steady-state power dissipation limit at 50 °C ambient. The SMBJ78AHM3_A/I datasheet explicitly references this pad size for all thermal and power ratings.
SMBJ78AHM3_A/I 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/I FAQ
1.How can I place an order for SMBJ78AHM3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ78AHM3_A/I 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/I reliable?
The price and inventory of SMBJ78AHM3_A/I 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/I is usually 5 days.
3.What payment methods are accepted for SMBJ78AHM3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ78AHM3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ78AHM3_A/I?
SMBJ78AHM3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ78AHM3_A/I 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/I?
For technical support, including SMBJ78AHM3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ78AHM3_A/I requirements.
6.How does Aetrix verify that SMBJ78AHM3_A/I is sourced from the original manufacturer or authorized distributors?
All SMBJ78AHM3_A/I 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/I meets industry standards.
7.What is the process for return or replacement of SMBJ78AHM3_A/I?
All SMBJ78AHM3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ78AHM3_A/I, 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/I part is unused and in its original packaging.
Return procedure for SMBJ78AHM3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ78AHM3_A/I Tags
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