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Vishay General Semiconductor - Diodes Division SMCJ78AHM3_A/I
- Part No.:
- SMCJ78AHM3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ78AHM3_A/I.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:7,469
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Product details
Overview
SMCJ78AHM3_A/I from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) in SMC (DO-214AB) package, designed to protect sensitive electronics against voltage transients induced by inductive load switching and lightning surges. It features a 78 V stand-off voltage (VWM), 126 V maximum clamping voltage (VC) at 11.9 A peak pulse current (IPPM), and 1500 W peak pulse power dissipation (PPPM) with 10/1000 μs waveform.
For engineers reviewing the SMCJ78AHM3_A/I datasheet, SMCJ78AHM3_A/I pinout, SMCJ78AHM3_A/I application, or SMCJ78AHM3_A/I equivalent, key selection criteria include clamping performance under 10/1000 μs surge, thermal resistance (RθJA = 75 °C/W), AEC-Q101 qualification status, halogen-free RoHS compliance, and compatibility with automated placement on PCBs requiring robust overvoltage protection for DC power rails and signal lines.
Technical Context
The SMCJ78AHM3_A/I operates as a unidirectional avalanche diode, leveraging glass-passivated junction technology for stable breakdown behavior and low incremental surge resistance. Its breakdown voltage (VBR) is specified at 86.7–95.8 V with 1 mA test current, and it exhibits a temperature coefficient of 0.106 %/°C - enabling predictable voltage drift across its -55 °C to +150 °C operating junction range.
Designed for transient suppression in DC circuits, it delivers fast response time (<1 ns), meets MSL level 1 per J-STD-020 (peak reflow 260 °C), and supports surge currents up to 200 A (IFSM, 8.3 ms half-sine) while maintaining low reverse leakage (<1.0 μA at VWM). Polarity is marked by a cathode band on the SMC package.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - maximum continuous reverse working voltage before clamping begins |
| VBR min/max | 86.7 V / 95.8 V at 1 mA - ensures reliable avalanche initiation within defined tolerance |
| VC @ IPPM | 126 V at 11.9 A - clamping voltage during 10/1000 μs surge, limiting stress on downstream ICs |
| PPPM | 1500 W - peak transient energy absorption capability under standardized surge waveform |
| RθJA | 75 °C/W - thermal resistance from junction to ambient, critical for derating above 25 °C |
| TJ max | +150 °C - maximum allowable junction temperature, supporting automotive under-hood use |
| Compliance | AEC-Q101 qualified, halogen-free, RoHS-compliant - suitable for automotive and industrial production |
Pinout & Package
Package: SMC (DO-214AB), surface-mount, matte tin-plated leads, 0.305" × 0.220" footprint, MSL Level 1, UL 94 V-0 molding compound.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Transient current sink | Connected to protected line; conducts surge current to ground when V > VBR |
| Anode | Reference/return path | Typically tied to system ground or low-impedance return plane for effective clamping |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable, repeatable breakdown characteristics and long-term reliability under repeated surge stress |
| AEC-Q101 qualification | Validated for automotive applications including engine control units and ADAS sensor interfaces |
| Halogen-free & RoHS-compliant | Meets environmental compliance requirements for global industrial and consumer electronics manufacturing |
| Low-profile SMC package | Enables high-density PCB layouts and compatibility with automated pick-and-place assembly |
| MSL Level 1 rating | Supports lead-free reflow soldering without moisture sensitivity concerns (peak 260 °C) |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Protecting 24 V CAN bus power supply lines in vehicle body control modules against load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VBAT and ground to clamp transients before they reach DC-DC converters and microcontrollers. Use Value: Limits clamped voltage to 126 V during 1500 W surges, preventing damage to 36 V-rated downstream regulators and ensuring ASIL-B functional safety compliance. | Use Scenario: Safeguarding analog output lines (e.g., 4–20 mA current loops) in factory automation pressure transmitters exposed to ESD and relay-switching noise. IC Role / Device Role / Timing Role: Bidirectional-capable unidirectional device used across signal and return paths to suppress common-mode and differential transients. Use Value: Sub-1 ns response and <1.0 μA leakage at 78 V enable precision signal integrity without loading the loop, meeting IEC 61000-4-2/4-4 immunity requirements. |
| Telecom DC Power Input Protection | Consumer Device USB Power Line Protection |
Use Scenario: Shielding 48 V PoE-powered equipment inputs from lightning-induced surges on outdoor Ethernet cables. IC Role / Device Role / Timing Role: Primary TVS on DC input rail upstream of hot-swap controllers and PMICs. Use Value: 1500 W PPPM rating and 126 V clamping withstand IEEE C62.41 Cat. C transients while maintaining thermal stability via RθJA = 75 °C/W. | Use Scenario: Adding secondary overvoltage protection on 5 V USB-C VBUS lines in portable speakers and docking stations. IC Role / Device Role / Timing Role: Standby clamping device parallel to primary protection, activated only during abnormal overvoltage events. Use Value: Low 78 V VWM allows clean operation during normal USB PD negotiation (up to 20 V), while 126 V VC prevents latch-up in connected SoCs during ESD events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ78A-E3/57T | Lower PPPM (400 W), SMA package (smaller footprint, higher RθJA = 110 °C/W), non-AEC-Q101 | Suitable for cost-sensitive consumer applications with lower surge threat levels | Select when space-constrained layouts prioritize size over automotive-grade ruggedness and 1500 W surge handling |
| SMCJ78AHE3_A/I | Same electrical specs and SMC package, but RoHS-compliant commercial grade (not halogen-free), no AEC-Q101 qualification | Applicable in industrial controls where halogen-free requirement is not mandated | Choose when halogen-free material is not required and AEC-Q101 certification is unnecessary for the target application |
Compared with SMCJ78AHM3_A/I, SMAJ78A-E3/57T offers reduced surge capacity and thermal performance in a smaller package, while SMCJ78AHE3_A/I matches form-factor and clamping but lacks halogen-free construction and automotive qualification - making SMCJ78AHM3_A/I the optimal choice for AEC-Q101-compliant, environmentally regulated, high-energy transient environments.
Availability
SMCJ78AHM3_A/I is available at Aetrix Electronics and suitable for automotive ECUs, industrial sensor nodes, telecom power supplies, and consumer USB-C power delivery systems requiring stable component supply with full traceability and lifecycle management.
Supply support for SMCJ78AHM3_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, MOSFETs, and protection devices with emphasis on reliability, efficiency, and application-specific optimization.
The SMCJ series is part of Vishay's TRANSZORB® TVS platform, engineered for high-energy transient suppression in harsh environments - particularly targeting automotive, industrial, and telecom infrastructure where robust overvoltage resilience is mandatory.
FAQ
What is the clamping voltage of the SMCJ78AHM3_A/I under a 10/1000 μs surge?
The SMCJ78AHM3_A/I has a maximum clamping voltage (VC) of 126 V when subjected to its rated peak pulse current of 11.9 A using the standard 10/1000 μs waveform. This value is measured per ANSI/IEEE C62.35 and ensures downstream components see limited overvoltage stress during transient events. The clamping performance is guaranteed across the full operating temperature range and forms the basis for circuit protection margin calculations in designs using the SMCJ78AHM3_A/I.
Is the SMCJ78AHM3_A/I qualified for automotive applications?
Yes, the SMCJ78AHM3_A/I is AEC-Q101 qualified, as confirmed by Vishay's ordering code suffix "HM3" and documentation in the SMCJ5.0A–SMCJ188CA datasheet (Document Number: 88394, Revision: 09-Jan-2024). This qualification validates its reliability for automotive use cases including engine control, body electronics, and ADAS sensor interfaces, covering temperature cycling, humidity testing, and surge endurance per the AEC-Q101 stress test standard.
What does the "HM3" suffix indicate in SMCJ78AHM3_A/I?
The "HM3" suffix in SMCJ78AHM3_A/I denotes halogen-free, RoHS-compliant, and AEC-Q101-qualified construction. Per Vishay's ordering information table, HM3 parts use halogen-free molding compound and meet JESD 201 Class 2 whisker resistance, distinguishing them from M3 (halogen-free, commercial grade) and HE3 (AEC-Q101, RoHS, non-halogen-free) variants. This makes the SMCJ78AHM3_A/I compliant with both environmental regulations and automotive reliability standards.
How does the thermal resistance of SMCJ78AHM3_A/I affect its power derating?
The SMCJ78AHM3_A/I has a typical junction-to-ambient thermal resistance (RθJA) of 75 °C/W on standard 0.31" × 0.31" copper pads. At ambient temperatures above 25 °C, its 6.5 W steady-state power dissipation must be linearly derated - for example, to ~4.5 W at 70 °C ambient. This derating directly impacts sustained leakage current handling and influences layout decisions such as pad size and copper pour area, which are critical for maintaining safe junction temperatures in high-reliability applications using the SMCJ78AHM3_A/I.
Can SMCJ78AHM3_A/I be used in bidirectional protection circuits?
No - the SMCJ78AHM3_A/I is a unidirectional TVS, identified by its "A" suffix and cathode band marking. For bidirectional protection, Vishay specifies the "CA" suffix (e.g., SMCJ78CA). Using the unidirectional SMCJ78AHM3_A/I in AC or symmetrical transient scenarios would result in forward conduction during negative excursions, potentially damaging the device or failing to suppress transients. Always match polarity: SMCJ78AHM3_A/I for DC rails with defined ground reference; SMCJ78CA for signal lines or AC-coupled paths.
SMCJ78AHM3_A/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AB, SMC
- Series:
- TransZorb®
- 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):
- 11.9A
- Power - Peak Pulse:
- 1500W (1.5kW)
- 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-214AB (SMC)
SMCJ78AHM3_A/I FAQ
1.How can I place an order for SMCJ78AHM3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ78AHM3_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 SMCJ78AHM3_A/I reliable?
The price and inventory of SMCJ78AHM3_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 SMCJ78AHM3_A/I is usually 5 days.
3.What payment methods are accepted for SMCJ78AHM3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ78AHM3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ78AHM3_A/I?
SMCJ78AHM3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ78AHM3_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 SMCJ78AHM3_A/I?
For technical support, including SMCJ78AHM3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ78AHM3_A/I requirements.
6.How does Aetrix verify that SMCJ78AHM3_A/I is sourced from the original manufacturer or authorized distributors?
All SMCJ78AHM3_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 SMCJ78AHM3_A/I meets industry standards.
7.What is the process for return or replacement of SMCJ78AHM3_A/I?
All SMCJ78AHM3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ78AHM3_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 SMCJ78AHM3_A/I part is unused and in its original packaging.
Return procedure for SMCJ78AHM3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ78AHM3_A/I Tags
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