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Vishay General Semiconductor - Diodes Division SMCG78A-M3/9AT
- Part No.:
- SMCG78A-M3/9AT
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-215AB, SMC Gull Wing
- Datasheet:
-
SMCG78A-M3/9AT.pdf
- Description:
- TVS DIODE 78VWM 126VC DO215AB
- Quantity:
- Payment:
- Shipping:
Inventory:6,134
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Product details
Overview
SMCG78A-M3/9AT from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in the SMCG (DO-215AB) surface-mount 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, 1500 W peak pulse power (10/1000 µs), 11.9 A maximum clamping current (IPPM), and 126 V clamping voltage (VC) - deployed in automotive power line and industrial sensor interface protection.
For engineers reviewing the SMCG78A-M3/9AT datasheet, SMCG78A-M3/9AT pinout, SMCG78A-M3/9AT application, or SMCG78A-M3/9AT equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, halogen-free RoHS compliance, thermal resistance (RθJA = 75 °C/W), and bidirectional variant compatibility - all critical for ESD/surge co-design in high-reliability embedded systems.
Technical Context
This TVS diode operates as a clamping device in parallel with protected circuitry, responding to transients within picoseconds via avalanche breakdown. Its glass-passivated junction ensures stable VBR tolerance (±5%), low incremental surge resistance, and repeatable clamping performance under repetitive 10/1000 µs surges up to 1500 W.
The SMCG78A-M3/9AT is rated for -55 °C to +150 °C operating junction temperature, meets MSL Level 1 per J-STD-020 (260 °C peak reflow), and supports automated SMT placement with matte tin-plated leads compliant to J-STD-002 and JESD 22-B102.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC/AC bias margin for protected ICs or MOSFET gates. |
| VBR (min/max) | 86.7 V / 95.8 V at IT = 1 mA - Tight breakdown window ensures predictable turn-on during transients without premature conduction. |
| VC @ IPPM | 126 V at 11.9 A - Clamping voltage limits downstream stress during worst-case 1500 W surge; enables design margin vs. 100 V rail systems. |
| PPPM | 1500 W (10/1000 µs) - Peak surge energy handling capacity validated on 8.0 mm × 8.0 mm copper pads; supports ISO 7637-2 Pulse 5a/b compliance. |
| TJ max. | +150 °C - Enables use in under-hood automotive environments and industrial enclosures without derating below full power. |
| RθJA | 75 °C/W - Thermal resistance informs PCB copper area requirements; 8.0 mm × 8.0 mm pad layout achieves specified PPPM rating. |
| AEC-Q101 | Qualified - Validated for automotive-grade reliability including HTOL, TC, UHAST, and ESD testing per AEC standard. |
Pinout & Package
Package: SMCG (DO-215AB) - surface-mount, low-profile gull-wing leaded case with cathode band marking; meets UL 94 V-0 flammability rating and JESD 201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal during forward conduction (unidirectional only) | Connected to ground or low-side return path; polarity-sensitive placement required for correct clamping direction. |
| Cathode | Current exit terminal during reverse-biased clamping | Connected to protected line (e.g., CAN_H, 12 V supply); band-marked end identifies this terminal on PCB. |
Key Features
| Feature | Design Value |
|---|---|
| Halogen-free, RoHS-compliant construction | M3 suffix confirms halogen-free molding compound and terminations - satisfies IPC-1752A material declaration and automotive OEM sustainability mandates. |
| Very fast response time | Sub-nanosecond avalanche turn-on ensures protection before transient energy couples into downstream ICs or sensors. |
| Low incremental surge resistance | Minimizes voltage overshoot during high-di/dt events (e.g., inductive switch-off), improving clamping precision across surge amplitude range. |
| Glass passivated chip junction | Enhances long-term stability of VBR and leakage under thermal cycling and humidity exposure - critical for 15-year automotive service life. |
| MSL Level 1 rating | Allows unlimited floor life and single-reflow processing at 260 °C peak - eliminates baking requirements and streamlines high-volume SMT manufacturing. |
Applications
| Automotive Power Line Protection | Industrial Sensor Interface |
|---|---|
Use Scenario: Protecting 12 V/24 V power rails in engine control units (ECUs) against load dump and alternator ripple. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery input and DC-DC converter input stage. Use Value: Withstands 1500 W ISO 7637-2 Pulse 5a (12 V system) and clamps to ≤126 V - preserving downstream regulator and MCU input integrity. |
Use Scenario: Shielding analog output lines (e.g., 4–20 mA current loop) of pressure/temperature sensors from ESD and cable discharge events. IC Role / Device Role / Timing Role: Parallel-connected TVS at sensor module connector, referenced to local ground plane. Use Value: 11.9 A IPPM capability handles IEC 61000-4-2 contact discharge (±8 kV) without degradation; low leakage (<1 µA at 78 V) avoids signal offset error. |
| Telecom DC Feeding Protection | Consumer Power Adapter Input |
Use Scenario: Safeguarding PoE (Power over Ethernet) midspan injectors against induced surges on 48 V DC feed lines. IC Role / Device Role / Timing Role: Unidirectional clamp on primary side of isolated DC-DC stage, cathode tied to 48 V bus. Use Value: 78 V VWM provides 30% margin above nominal 48 V, while 126 V VC ensures secondary-side isolation remains intact during surge. |
Use Scenario: Input-stage transient suppression in AC-DC adapters for smart home hubs and IoT gateways. IC Role / Device Role / Timing Role: TVS mounted at AC rectifier output, protecting bulk capacitor and primary controller IC. Use Value: AEC-Q101 qualification and 150 °C TJ max support extended operation in thermally constrained enclosures; M3 suffix meets global RoHS/halogen bans. |
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 | Same VWM (78 V) and PPPM (1500 W), but SMA (DO-214AC) package; RθJA = 85 °C/W; not AEC-Q101 qualified. | Limited to industrial/commercial use; unsuitable for automotive under-hood deployment due to lower thermal performance and qualification gap. | Select when cost sensitivity outweighs automotive qualification and thermal margin requirements. |
| SMCG78CA-M3/9AT | Bidirectional variant with identical VWM (78 V), same SMCG package and M3 suffix, but symmetrical clamping in both polarities. | Required for AC-coupled or floating signal lines (e.g., RS-485, CAN FD differential pairs) where polarity reversal may occur. | Choose for bidirectional protection needs; note that ID leakage doubles for VWM ≤10 V - irrelevant here given 78 V rating. |
Compared with SMAJ78A-E3/57T, SMCG78A-M3/9AT offers superior thermal management and automotive qualification; versus SMCG78CA-M3/9AT, it provides optimized unidirectional clamping with tighter VBR tolerance and lower capacitance - ideal for DC power rail protection where polarity is fixed.
Availability
SMCG78A-M3/9AT is available at Aetrix Electronics and suitable for automotive ECUs, industrial sensor modules, telecom power injectors, and consumer power adapter designs requiring stable component supply and long-term lifecycle assurance.
Supply support for SMCG78A-M3/9AT 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, MOSFETs, optoelectronics, and passive components with emphasis on reliability and application-specific performance.
The SMCG series was engineered for high-power transient suppression in space-constrained, high-reliability environments - particularly targeting automotive, industrial, and telecom infrastructure where AEC-Q101 compliance and 150 °C operation are mandatory.
FAQ
What is the clamping voltage of SMCG78A-M3/9AT at its rated peak pulse current?
The SMCG78A-M3/9AT has a maximum clamping voltage (VC) of 126 V when subjected to its rated peak pulse current (IPPM) of 11.9 A under the standard 10/1000 µs waveform. This value is measured with the device mounted on 8.0 mm × 8.0 mm copper pads per the datasheet test condition - critical for validating voltage margin in 100 V-rated downstream circuitry. The SMCG78A-M3/9AT maintains this clamping performance across its full operating temperature range.
Is SMCG78A-M3/9AT qualified for automotive applications?
Yes, SMCG78A-M3/9AT is AEC-Q101 qualified, having passed stress tests including high-temperature operating life (HTOL), temperature cycling (TC), unbiased highly accelerated stress test (UHAST), and ESD (HBM/MM). Its M3 suffix confirms halogen-free, RoHS-compliant construction meeting automotive OEM material requirements. The SMCG78A-M3/9AT is approved for use in engine control units, body electronics, and ADAS power domains where 150 °C junction temperature capability is essential.
How does the SMCG78A-M3/9AT differ from the SMCG78CA-M3/9AT?
The SMCG78A-M3/9AT is unidirectional, with cathode band marking and asymmetric conduction - optimized for DC power rail protection. The SMCG78CA-M3/9AT is bidirectional, lacking polarity marking and providing symmetrical clamping in both directions - required for AC or differential signal lines like CAN or RS-485. Both share identical VWM (78 V), PPPM (1500 W), and SMCG package, but the SMCG78A-M3/9AT exhibits tighter VBR tolerance and lower junction capacitance in the forward direction.
What is the thermal resistance of SMCG78A-M3/9AT, and how does it affect PCB layout?
The SMCG78A-M3/9AT has a typical junction-to-ambient thermal resistance (RθJA) of 75 °C/W when mounted on the recommended 0.31" × 0.31" (8.0 mm × 8.0 mm) copper pads per terminal. This value directly determines minimum copper area needed to sustain full 1500 W pulse power without exceeding 150 °C junction temperature. Reducing pad size increases RθJA, requiring derating of PPPM per Figure 2 in the datasheet - the SMCG78A-M3/9AT's performance is thus layout-dependent and must be validated in final board design.
Does SMCG78A-M3/9AT meet moisture sensitivity level (MSL) requirements for lead-free reflow?
Yes, SMCG78A-M3/9AT meets MSL Level 1 per J-STD-020, with a maximum peak reflow temperature of 260 °C - enabling use in standard lead-free SMT processes without dry-packaging or baking. Its matte tin-plated leads comply with J-STD-002 and JESD 22-B102 solderability standards, and the gull-wing lead form supports automated optical inspection (AOI) and high-yield placement. This MSL rating applies specifically to the SMCG78A-M3/9AT variant and is confirmed in the Vishay document 88457.
SMCG78A-M3/9AT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-215AB, SMC Gull Wing
- 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:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMCG)
SMCG78A-M3/9AT FAQ
1.How can I place an order for SMCG78A-M3/9AT through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCG78A-M3/9AT 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 SMCG78A-M3/9AT reliable?
The price and inventory of SMCG78A-M3/9AT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCG78A-M3/9AT is usually 5 days.
3.What payment methods are accepted for SMCG78A-M3/9AT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCG78A-M3/9AT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCG78A-M3/9AT?
SMCG78A-M3/9AT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCG78A-M3/9AT 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 SMCG78A-M3/9AT?
For technical support, including SMCG78A-M3/9AT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCG78A-M3/9AT requirements.
6.How does Aetrix verify that SMCG78A-M3/9AT is sourced from the original manufacturer or authorized distributors?
All SMCG78A-M3/9AT 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 SMCG78A-M3/9AT meets industry standards.
7.What is the process for return or replacement of SMCG78A-M3/9AT?
All SMCG78A-M3/9AT units undergo pre-shipment inspection (PSI). If there is an issue with SMCG78A-M3/9AT, 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 SMCG78A-M3/9AT part is unused and in its original packaging.
Return procedure for SMCG78A-M3/9AT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCG78A-M3/9AT Tags
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