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Vishay General Semiconductor - Diodes Division SMCG78A-E3/57T
- Part No.:
- SMCG78A-E3/57T
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-215AB, SMC Gull Wing
- Datasheet:
-
SMCG78A-E3/57T.pdf
- Description:
- TVS DIODE 78VWM 126VC DO215AB
- Quantity:
- Payment:
- Shipping:
Inventory:1,700
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Product details
Overview
SMCG78A-E3/57T from Vishay General Semiconductor is a unidirectional surface-mount TransZORB® transient voltage suppressor (TVS) in the SMCG (DO-215AB) package, with a 78 V standoff voltage (VWM), 86.7–95.8 V breakdown voltage (VBR), 1500 W peak pulse power (PPPM), and 11.9 A peak pulse current (IPPM) at 10/1000 µs. It protects MOSFETs, ICs, and sensor signal lines in automotive power electronics against inductive switching transients.
For engineers reviewing the SMCG78A-E3/57T datasheet, SMCG78A-E3/57T pinout, SMCG78A-E3/57T application, or SMCG78A-E3/57T equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, thermal resistance (RθJA = 75 °C/W), clamping behavior (VC = 126 V at IPPM), and bidirectional variant compatibility for robust overvoltage design.
Technical Context
This TVS diode operates as a clamping device in parallel with sensitive circuit nodes, activating when reverse voltage exceeds VBR to divert surge current away from downstream components. Its glass-passivated junction ensures stable breakdown characteristics and low leakage (ID ≤ 1.0 µA at VWM).
Designed for high-reliability automotive applications, it meets AEC-Q101 stress testing requirements and is rated for TJ = –55 °C to +150 °C operation. The DO-215AB package supports automated placement and achieves MSL level 1 moisture sensitivity with 260 °C lead-free reflow compatibility.
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 IT = 1.0 mA - Confirmed breakdown range ensuring reliable turn-on margin above VWM |
| VC @ IPPM | 126 V at IPPM = 11.9 A (10/1000 µs) - Clamped voltage during worst-case surge, limiting stress on protected ICs |
| PPPM | 1500 W - Peak transient energy handling capacity under standardized 10/1000 µs waveform |
| RθJA | 75 °C/W - Thermal resistance from junction to ambient on 8.0 mm × 8.0 mm copper pads, critical for thermal derating |
| TJ max | +150 °C - Maximum junction temperature enabling use in under-hood automotive environments |
| AEC-Q101 | Qualified - Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD |
Pinout & Package
Package: SMCG (DO-215AB) - Low-profile, gull-wing surface-mount case with matte tin-plated leads solderable per J-STD-002 and JESD 22-B102; polarity indicated by cathode band on unidirectional devices.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal during forward conduction | Connected to ground or lower-potential node in unidirectional protection configuration |
| Cathode | Current exit terminal during forward conduction; high-impedance terminal under normal reverse bias | Connected to protected line (e.g., 12 V rail or sensor output); clamps to anode when VAK > VBR |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR tolerance and long-term reliability under thermal cycling and humidity exposure |
| Low incremental surge resistance | Minimizes voltage overshoot during fast transients, improving clamping precision |
| MSL Level 1 rating | Enables standard SMT reflow without baking, reducing manufacturing complexity and cost |
| AEC-Q101 qualification | Validates suitability for automotive powertrain, body control, and ADAS subsystems |
| 1500 W PPPM capability | Supports protection against ISO 7637-2 Pulse 1, 2a, 3a/b, and IEC 61000-4-5 surges in 12 V systems |
Applications
| Automotive Power Distribution | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Protecting 12 V supply rails feeding ECUs, lighting modules, and window lift controllers from load-dump and inductive kickback. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and input filter capacitor to clamp transients before they reach LDOs or microcontrollers. Use Value: Limits peak voltage to 126 V during 11.9 A surges, preventing damage to 36 V-rated input stages and meeting OEM EMC requirements. | Use Scenario: Safeguarding analog outputs of pressure, temperature, and position sensors connected to PLCs or motor drives. IC Role / Device Role / Timing Role: Parallel-connected TVS on 4–20 mA or 0–10 V signal lines to absorb field-induced transients without affecting DC accuracy. Use Value: Delivers <1.0 µA leakage at 78 V, preserving sensor offset and gain stability while clamping ESD events up to ±30 kV contact discharge. |
| Telecom Power Supply Input | Consumer Appliance Motor Control |
Use Scenario: Input-stage protection for AC/DC adapters and PoE injectors exposed to lightning-induced surges on primary-side DC bus. IC Role / Device Role / Timing Role: Primary-side TVS across bulk capacitor terminals to shunt energy from coupled surges on AC mains or Ethernet cables. Use Value: Withstands 1500 W peak pulses and maintains clamping below 126 V, allowing downstream MOVs and fuses to operate within safe coordination margins. | Use Scenario: Overvoltage suppression on H-bridge gate drivers and flyback diodes in washing machine or HVAC blower inverters. IC Role / Device Role / Timing Role: Bidirectional-capable variant (SMCG78CA) used across motor phase terminals to clamp commutation spikes in both directions. Use Value: Enables direct substitution with SMCG78CA for bidirectional clamping while retaining same footprint, thermal performance, and 126 V VC rating. |
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), smaller SMA (DO-214AC) package, RθJA = 110 °C/W | Suitable for lower-energy transients; limited thermal margin in high-ambient industrial enclosures | Select when board space is constrained and surge threat level is defined per IEC 61000-4-2 only |
| SMCJ78A-E3/57T | Same DO-215AB package but higher PPPM (1500 W), identical VWM/VBR/VC, RθJA = 75 °C/W | Drop-in replacement with identical mechanical and thermal behavior; differs only in JEDEC prefix (SMCJ vs SMCG) | Choose if sourcing flexibility is needed-SMCJ78A-E3/57T shares full pinout, footprint, and performance but may differ in traceability or lot history |
Compared with SMCG78A-E3/57T, SMAJ78A-E3/57T offers reduced surge handling and thermal capability in a smaller package, while SMCJ78A-E3/57T provides identical protection performance with equivalent manufacturability-making it the preferred alternative for drop-in continuity planning.
Availability
SMCG78A-E3/57T is available at Aetrix Electronics and suitable for automotive power distribution, industrial sensor interface protection, and telecom power supply input requiring stable component supply and AEC-Q101 compliance.
Supply support for SMCG78A-E3/57T 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 and application-specific performance.
The SMCG series was developed to deliver high-power, AEC-Q101-qualified transient suppression in compact surface-mount packages for automotive and industrial power systems where thermal robustness and surge immunity are critical.
FAQ
What is the clamping voltage of SMCG78A-E3/57T under maximum surge conditions?
The SMCG78A-E3/57T clamps to 126 V when subjected to its rated peak pulse current of 11.9 A using the 10/1000 µs waveform. This value is measured under standardized test conditions with 8.0 mm × 8.0 mm copper pads per terminal and represents the maximum voltage seen by protected circuitry during worst-case transient events. The SMCG78A-E3/57T maintains this clamping performance across its full operating temperature range.
Is SMCG78A-E3/57T qualified for automotive applications?
Yes, SMCG78A-E3/57T is AEC-Q101 qualified, having passed stress tests including high-temperature reverse bias, temperature cycling, and ESD. Its construction-glass-passivated junction, matte tin-plated leads, and DO-215AB package rated for MSL level 1-supports deployment in engine control units, body electronics, and ADAS modules. The SMCG78A-E3/57T datasheet explicitly lists AEC-Q101 qualification in the mechanical data section.
How does the SMCG78A-E3/57T differ from the SMCG78CA variant?
The SMCG78A-E3/57T is unidirectional, with polarity marked by a cathode band and intended for DC rail protection; the SMCG78CA is bidirectional, with no polarity marking and designed for AC or differential signal line protection. Both share identical VWM (78 V), VBR (86.7–95.8 V), PPPM (1500 W), and VC (126 V), but the SMCG78CA conducts symmetrically in both directions. The SMCG78A-E3/57T cannot substitute for SMCG78CA in AC-coupled paths without circuit redesign.
What is the thermal resistance of SMCG78A-E3/57T, and how does it affect layout?
The SMCG78A-E3/57T has a typical junction-to-ambient thermal resistance (RθJA) of 75 °C/W when mounted on 0.31" × 0.31" (8.0 mm × 8.0 mm) copper pads per terminal. This value assumes minimum recommended pad layout per Vishay's datasheet Figure 6. To maintain safe junction temperatures under repeated surges, PCB layout must replicate these pad dimensions and avoid excessive trace length or isolation. The SMCG78A-E3/57T thermal performance degrades significantly if pads are undersized or thermally isolated.
Can SMCG78A-E3/57T be used in place of SMAJ78A-E3/57T?
No-SMCG78A-E3/57T is not a direct replacement for SMAJ78A-E3/57T due to differences in package (DO-215AB vs DO-214AC), thermal resistance (75 vs 110 °C/W), and surge rating (1500 W vs 400 W). While both have the same VWM and VC, the SMCG78A-E3/57T requires larger PCB pads and delivers three times the pulse power handling. Substituting SMCG78A-E3/57T into an SMAJ-designed layout risks solder joint stress and insufficient thermal relief unless pad geometry is updated to match DO-215AB requirements.
SMCG78A-E3/57T 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-E3/57T FAQ
1.How can I place an order for SMCG78A-E3/57T through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCG78A-E3/57T 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-E3/57T reliable?
The price and inventory of SMCG78A-E3/57T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCG78A-E3/57T is usually 5 days.
3.What payment methods are accepted for SMCG78A-E3/57T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCG78A-E3/57T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCG78A-E3/57T?
SMCG78A-E3/57T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCG78A-E3/57T 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-E3/57T?
For technical support, including SMCG78A-E3/57T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCG78A-E3/57T requirements.
6.How does Aetrix verify that SMCG78A-E3/57T is sourced from the original manufacturer or authorized distributors?
All SMCG78A-E3/57T 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-E3/57T meets industry standards.
7.What is the process for return or replacement of SMCG78A-E3/57T?
All SMCG78A-E3/57T units undergo pre-shipment inspection (PSI). If there is an issue with SMCG78A-E3/57T, 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-E3/57T part is unused and in its original packaging.
Return procedure for SMCG78A-E3/57T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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