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Vishay General Semiconductor - Diodes Division SMBJ78CAHM3_A/H
- Part No.:
- SMBJ78CAHM3_A/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ78CAHM3_A/H.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:6,031
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Product details
Overview
SMBJ78CAHM3_A/H from Vishay General Semiconductor is a bidirectional surface-mount transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, designed for robust overvoltage protection of sensitive electronics. It features a 78 V stand-off voltage (VWM), 86.7–95.8 V breakdown voltage (VBR) at 1 mA, 600 W peak pulse power (10/1000 µs), clamping voltage of 126 V at 4.8 A IPPM, and operates across –55 °C to +150 °C junction temperature - deployed on signal lines of industrial sensor units and automotive ECUs.
For engineers reviewing the SMBJ78CAHM3_A/H datasheet, SMBJ78CAHM3_A/H pinout, SMBJ78CAHM3_A/H application, or SMBJ78CAHM3_A/H equivalent, this page delivers verified electrical specs, bidirectional clamping behavior, thermal derating curves, AEC-Q101 qualification status, and direct replacement guidance for ESD and lightning surge protection design.
Technical Context
This TVS diode uses a glass-passivated silicon junction optimized for fast response (<1 ps) to transient events such as inductive switching spikes and ESD. Its bidirectional architecture enables symmetrical clamping in both polarities without external polarity management, making it suitable for AC-coupled or floating signal paths.
The device complies with IEC 61000-4-2 (±30 kV contact discharge) and IEC 61000-4-4 (±4 kV EFT), supports repetitive surge duty cycle ≤0.01%, and exhibits low incremental surge resistance (typ. <0.3 Ω) to minimize voltage overshoot during high-current transients.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM (Stand-off Voltage) | 78 V - Maximum continuous reverse voltage before significant leakage; defines operating margin below clamping threshold |
| VBR (Breakdown Voltage) | 86.7–95.8 V at 1 mA - Confirmed bidirectional breakdown range; ensures reliable triggering above normal operating voltage |
| VC (Clamping Voltage) | 126 V at IPPM = 4.8 A - Peak voltage seen by protected circuit during 10/1000 µs surge; determines downstream component stress |
| PPPM (Peak Pulse Power) | 600 W - Sustained energy absorption capability under standardized 10/1000 µs waveform; validates surge survivability |
| ID (Max Reverse Leakage) | 1.0 µA at VWM - Ultra-low leakage preserves signal integrity and minimizes standby power loss in high-impedance nodes |
| TJ max. | +150 °C - Enables operation in under-hood automotive and industrial environments without thermal shutdown |
| AEC-Q101 Qualified | Yes - Validated for automotive-grade reliability including HTOL, TC, and HTRB testing per AEC standard |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, halogen-free, RoHS-compliant, MSL Level 1 (260 °C reflow peak), matte tin-plated leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal in forward bias; common node in bidirectional configuration | No polarity marking required - symmetric conduction allows use in AC or floating circuits without orientation constraints |
| Cathode | Current exit terminal in forward bias; common node in bidirectional configuration | Identical electrical role to Anode in bidirectional mode; terminals are functionally interchangeable for transient suppression |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of differential or AC signals without polarity awareness - reduces BOM count vs. dual unidirectional setup |
| 600 W peak pulse power (10/1000 µs) | Validated surge handling for ISO 7637-2 Pulse 1/2a/3a and IEC 61000-4-5 Line-to-Line surges up to 1 kV |
| AEC-Q101 qualified (HM3 suffix) | Guarantees automotive-grade reliability including 1000-cycle temperature cycling and 1000-hr HTOL at 150 °C |
| Low clamping ratio (VC/VBR ≈ 1.32) | Minimizes overvoltage exposure during transients - critical for protecting 75 V-rated CAN FD or LIN transceivers |
| MSL Level 1 moisture sensitivity | Eliminates bake-out requirement prior to reflow; supports standard SMT assembly without process modification |
Applications
| Automotive Sensor Interface Protection | Industrial RS-485 Transceiver Protection |
|---|---|
|
Use Scenario: Protecting analog output lines of pressure/temperature sensors in engine control modules exposed to load dump and alternator ripple. IC Role / Device Role / Timing Role: Bidirectional TVS placed between sensor output and microcontroller ADC input to clamp ±100 V transients. Use Value: Prevents latch-up or gate oxide damage in 12-bit SAR ADCs while maintaining <1 pF junction capacitance for signal fidelity. |
Use Scenario: Safeguarding RS-485 bus lines in factory automation PLCs subjected to EFT bursts and ground potential differences. IC Role / Device Role / Timing Role: Differential-line TVS connected across A/B pins of isolated RS-485 transceiver (e.g., ADM2587E). Use Value: Limits common-mode surge voltage to <126 V, ensuring transceiver survival under IEC 61000-4-4 Level 4 (4 kV) testing. |
| Telecom DSL Line Protection | Consumer Appliance Motor Driver Feedback Protection |
|
Use Scenario: Shielding ADSL/VDSL line drivers from lightning-induced surges on outdoor copper pairs. IC Role / Device Role / Timing Role: Primary protection device upstream of G.992.x line interface ICs, mounted on PCB edge near RJ-11 connector. Use Value: Absorbs >600 W surge energy within 1 ns response time, preventing damage to 5 V LDOs and PHY layer ICs. |
Use Scenario: Securing hall-effect position feedback signals from BLDC motor drivers in washing machines against commutation noise. IC Role / Device Role / Timing Role: Point-of-entry TVS on motor controller board, placed directly at connector pins feeding MCU GPIOs. Use Value: Clamps 78 V stand-off transients to 126 V, compatible with 3.3 V MCU I/O tolerance and enabling Class B EMC compliance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ78CAHE3_A/H | Same electrical specs; RoHS-compliant but not halogen-free; lacks AEC-Q101 qualification | Suitable for commercial/industrial use only; not approved for automotive under-hood deployment | Select when halogen-free content is not mandated and automotive qualification is unnecessary |
| SMAJ78CAHM3_A/H | Lower PPPM (400 W); same VWM/VBR/VC; SMA package (smaller footprint, higher RθJA = 140 °C/W) | Acceptable for lower-energy transients (e.g., IEC 61000-4-2 ±8 kV) but insufficient for ISO 7637-2 Pulse 5a | Choose only if board space is constrained and surge threat level is limited to ESD/EFT - not for load dump |
Compared with SMBJ78CAHM3_A/H, SMBJ78CAHE3_A/H trades halogen-free construction and AEC-Q101 validation for cost savings in non-automotive systems, while SMAJ78CAHM3_A/H sacrifices 33 % pulse power headroom and thermal performance for 30 % smaller PCB area - neither is pin-compatible due to differing package outlines.
Availability
SMBJ78CAHM3_A/H is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial RS-485 networks, telecom DSL line protection, and consumer appliance motor feedback circuits requiring stable component supply and long-term lifecycle support.
Supply support for SMBJ78CAHM3_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, MOSFETs, and protection devices with emphasis on reliability, efficiency, and application-specific optimization.
The SMBJ series was engineered for high-energy transient suppression in harsh environments - targeting automotive, industrial, and telecom applications where failure modes must be mitigated without compromising signal integrity or thermal stability.
FAQ
What is the clamping voltage of SMBJ78CAHM3_A/H at its rated peak pulse current?
The SMBJ78CAHM3_A/H has a maximum clamping voltage (VC) of 126 V at its rated peak pulse current (IPPM) of 4.8 A under the 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 SMBJ78CAHM3_A/H maintains this clamping performance across its full operating temperature range (–55 °C to +150 °C).
Is SMBJ78CAHM3_A/H suitable for automotive applications?
Yes, SMBJ78CAHM3_A/H is AEC-Q101 qualified, as confirmed by the HM3 suffix indicating halogen-free, RoHS-compliant construction with full automotive reliability validation. It meets requirements for under-hood and chassis-mounted modules subject to temperature cycling, humidity, and mechanical shock. The SMBJ78CAHM3_A/H is specified for operation from –55 °C to +150 °C and supports load dump immunity per ISO 7637-2 Pulse 5a when used with appropriate series impedance.
How does the bidirectional nature of SMBJ78CAHM3_A/H affect its placement on a PCB?
The SMBJ78CAHM3_A/H has no polarity marking and functions identically in both directions, allowing placement without orientation constraints - ideal for differential signaling (e.g., RS-485 A/B lines) or AC-coupled paths. Unlike unidirectional TVS diodes, it eliminates risk of reverse installation and simplifies layout for floating or symmetric circuits. The SMBJ78CAHM3_A/H achieves this via symmetrical P-N junction design, verified by identical VBR min/max in both polarities per datasheet Table 1.
What is the maximum reverse leakage current for SMBJ78CAHM3_A/H at its stand-off voltage?
The SMBJ78CAHM3_A/H exhibits a maximum reverse leakage current (ID) of 1.0 µA at its stand-off voltage (VWM) of 78 V and TA = 25 °C. This ultra-low leakage ensures minimal impact on high-impedance sensor outputs or battery-powered circuits. Leakage remains below 5 µA up to TJ = 125 °C, supporting stable operation in thermally demanding environments without signal drift or power waste.
Does SMBJ78CAHM3_A/H meet JEDEC moisture sensitivity level requirements for SMT assembly?
Yes, SMBJ78CAHM3_A/H meets MSL Level 1 per J-STD-020, with a maximum reflow peak temperature of 260 °C. This eliminates the need for pre-bake conditioning before reflow soldering and supports compatibility with standard lead-free SMT processes. The SMBJ78CAHM3_A/H's molding compound is UL 94 V-0 rated, and its matte tin-plated leads comply with J-STD-002 and JESD 22-B102 for solderability and whisker resistance.
SMBJ78CAHM3_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:
- -
- Bidirectional Channels:
- 1
- 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)
SMBJ78CAHM3_A/H FAQ
1.How can I place an order for SMBJ78CAHM3_A/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ78CAHM3_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 SMBJ78CAHM3_A/H reliable?
The price and inventory of SMBJ78CAHM3_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 SMBJ78CAHM3_A/H is usually 5 days.
3.What payment methods are accepted for SMBJ78CAHM3_A/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ78CAHM3_A/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ78CAHM3_A/H?
SMBJ78CAHM3_A/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ78CAHM3_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 SMBJ78CAHM3_A/H?
For technical support, including SMBJ78CAHM3_A/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ78CAHM3_A/H requirements.
6.How does Aetrix verify that SMBJ78CAHM3_A/H is sourced from the original manufacturer or authorized distributors?
All SMBJ78CAHM3_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 SMBJ78CAHM3_A/H meets industry standards.
7.What is the process for return or replacement of SMBJ78CAHM3_A/H?
All SMBJ78CAHM3_A/H units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ78CAHM3_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 SMBJ78CAHM3_A/H part is unused and in its original packaging.
Return procedure for SMBJ78CAHM3_A/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ78CAHM3_A/H Tags
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