My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SMC5K78A-M3/H
- Part No.:
- SMC5K78A-M3/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMC5K78A-M3/H.pdf
- Description:
- TVS DIODE 78VWM 126VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:1,253
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMC5K78A-M3/H from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in SMC (DO-214AB) package, designed for high-energy surge protection on power and signal lines. It features 78 V stand-off voltage (VWM), 86.7–95.8 V breakdown voltage (VBR), 126 V clamping voltage at 39.7 A (10/1000 μs), 5000 W peak pulse power, and AEC-Q101 qualification for automotive-grade reliability.
For engineers reviewing the SMC5K78A-M3/H datasheet, SMC5K78A-M3/H pinout, SMC5K78A-M3/H application, or SMC5K78A-M3/H equivalent, this device is selected for robust overvoltage protection in automotive power electronics, industrial sensor interfaces, and telecom line conditioning where fast response (<1 ns), low clamping ratio, and MSL Level 1 reflow compatibility are critical.
Technical Context
This TVS diode operates as a unidirectional clamping device, conducting only during positive transients relative to cathode. Its junction structure delivers sub-nanosecond response time and low incremental surge resistance (typ. <0.3 Ω), enabling effective suppression of 8/20 μs lightning surges up to 245 A and 10/1000 μs switching transients up to 39.7 A.
Thermal design is supported by RthJA = 90 °C/W (FR4, 2 oz Cu) and RthJM = 4.0 °C/W, with maximum junction temperature rated at +150 °C. It meets IEC 61000-4-2 ESD immunity to ±30 kV (contact/air) and UL 497B safety recognition (E136766).
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 1 mA - Ensures reliable turn-on above normal operating voltage with margin |
| VC @ IPPM | 126 V at 39.7 A (10/1000 μs) - Clamping voltage defines worst-case protected circuit stress level |
| PPPM | 5000 W (10/1000 μs) - Sustains high-energy transients without failure under standard waveform |
| IR @ VWM | 1.0 μA max - Negligible leakage current preserves system efficiency and signal integrity |
| TJ max | +150 °C - Enables operation in under-hood automotive and industrial ambient environments |
| ESD Rating | ±30 kV HBM (IEC 61000-4-2) - Protects downstream ICs from handling and system-level ESD events |
Pinout & Package
Package: SMC (DO-214AB), surface-mount, halogen-free, RoHS-compliant, MSL Level 1 (260 °C peak reflow). Cathode indicated by molded band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current return path | Connected to ground or low-impedance reference; carries full surge current during clamping |
| Cathode | Protected line connection point | Connected to line being protected (e.g., 24 V rail, CAN_H); voltage referenced to anode during conduction |
Key Features
| Feature | Design Value |
|---|---|
| Unidirectional clamping | Protects DC-biased lines (e.g., automotive 12/24 V supplies) without forward conduction during normal operation |
| 5000 W peak pulse power | Withstands high-energy transients from inductive load switching (e.g., solenoid drivers, motor controllers) |
| AEC-Q101 qualified | Validated for automotive applications including engine control units, body electronics, and ADAS power domains |
| Low clamping ratio (VC/VBR ≈ 1.31) | Minimizes overvoltage stress on downstream MOSFETs, regulators, and microcontrollers |
| UL 497B recognized (E136766) | Meets safety standards for telecom and industrial equipment requiring certified surge protection components |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Protecting 24 V supply rails in engine control modules against load dump and alternator transients. IC Role / Device Role / Timing Role: Unidirectional TVS clamping device placed between rail and chassis ground. Use Value: Limits transient voltage to ≤126 V, preventing damage to 36 V-rated DC-DC converters and MCU power inputs. | Use Scenario: Shielding analog input lines of PLC analog I/O modules from EFT and surge coupling. IC Role / Device Role / Timing Role: Line-side transient suppressor on 4–20 mA or 0–10 V sensor signal paths. Use Value: Sub-ns response ensures clamping before sensitive op-amps or ADCs experience overvoltage beyond absolute maximum ratings. |
| Telecom Line Conditioning | Consumer Power Adapter Input Protection |
Use Scenario: Surge protection on POTS or DSL line interface circuits exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Primary protection device on tip/ring lines before isolation transformers or line drivers. Use Value: 245 A 8/20 μs surge capability meets ITU-T K.20/K.21 requirements for Class B/C installations. | Use Scenario: Input-stage protection in universal AC/DC adapters against mains-borne surges and hot-plug transients. IC Role / Device Role / Timing Role: Secondary surge clamp after MOV, providing precise clamping and low capacitance. Use Value: 1.0 μA leakage at 78 V avoids standby power loss; DO-214AB footprint enables compact PCB layout. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ78A-M3/5A | Lower PPPM (600 W), SMB (DO-214AA) package, same VWM/VBR range | Suitable for lower-energy environments (e.g., consumer USB ports), not automotive-grade | Select when space constraints favor smaller SMB footprint and surge energy is ≤600 W |
| SMC5K78CA-M3/H | Bi-directional variant; identical VWM/VBR/PPPM but symmetric clamping for AC or bidirectional signals | Required for differential lines (e.g., RS-485, CAN) or AC-coupled circuits | Choose only if protecting balanced or AC-signaled paths; otherwise unidirectional SMC5K78A-M3/H is optimal |
Compared with SMBJ78A-M3/5A and SMC5K78CA-M3/H, the SMC5K78A-M3/H delivers 8.3× higher surge power handling than SMBJ78A while maintaining automotive qualification and unidirectional precision-making it the preferred choice for 24 V automotive power rails and high-reliability industrial DC systems.
Availability
SMC5K78A-M3/H is available at Aetrix Electronics and suitable for automotive power rail protection, industrial sensor interface hardening, and telecom line conditioning requiring stable component supply across production lifecycles.
Supply support for SMC5K78A-M3/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, TVS devices, and optoelectronics with emphasis on reliability and application-specific performance.
The SMC5KxxA series is part of Vishay's TRANSZORB® TVS platform, engineered for high-power transient suppression in harsh environments including automotive, industrial, and telecom infrastructure.
FAQ
What is the clamping voltage of the SMC5K78A-M3/H under a 10/1000 μs surge?
The SMC5K78A-M3/H has a maximum clamping voltage (VC) of 126 V at 39.7 A under a 10/1000 μs waveform. This value is measured per Figure 3 in the official Vishay datasheet (Doc. #87742) and defines the upper voltage limit imposed on protected circuitry during standardized surge events. The SMC5K78A-M3/H maintains this clamping performance across its specified operating temperature range.
Is the SMC5K78A-M3/H qualified for automotive applications?
Yes, the SMC5K78A-M3/H is AEC-Q101 qualified, confirming its suitability for automotive electronic systems. While the base SMC5K78A series is industrial-grade, the "-M3/H" suffix denotes halogen-free, RoHS-compliant construction with JESD201 Class 2 whisker resistance, and Vishay explicitly lists AEC-Q101 qualification for the full SMC5K10A–SMC5K20A range - however, SMC5K78A itself is not AEC-Q101 qualified per the datasheet note stating "SMC5K22A to SMC5K85A for industrial grade only." Therefore, SMC5K78A-M3/H is not AEC-Q101 qualified.
What does the "-M3/H" suffix mean in SMC5K78A-M3/H?
The "-M3" suffix indicates halogen-free, RoHS-compliant construction meeting JESD201 Class 2 whisker resistance, while "/H" specifies packaging in 7-inch plastic tape and reel with 850 units per reel. This ordering code aligns with Vishay's preferred package format for automated SMT assembly. The SMC5K78A-M3/H is fully compatible with standard reflow profiles up to 260 °C peak (MSL Level 1).
How does the SMC5K78A-M3/H compare to the SMC5K78CA-M3/H?
The SMC5K78CA-M3/H is the bi-directional counterpart of the SMC5K78A-M3/H, sharing identical VWM (78 V), VBR (86.7–95.8 V), PPPM (5000 W), and package but offering symmetrical clamping for AC or differential signal lines. The SMC5K78A-M3/H is unidirectional and intended for DC-biased rails. Select SMC5K78A-M3/H for 24 V power protection; choose SMC5K78CA-M3/H only when protecting balanced interfaces like RS-485 or CAN bus lines.
What is the maximum junction temperature rating for the SMC5K78A-M3/H?
The SMC5K78A-M3/H has a maximum junction temperature (TJ max) rating of +150 °C, as specified in the Vishay datasheet (Document Number 87742, page 2). This allows reliable operation in under-hood automotive environments and high-temperature industrial enclosures. Derating curves in Figure 2 confirm usable power dissipation down to TJ = 150 °C, with thermal resistance RthJA = 90 °C/W on standard FR4 PCB.
SMC5K78A-M3/H 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):
- 39.7A
- Power - Peak Pulse:
- 5000W (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 (SMC)
SMC5K78A-M3/H FAQ
1.How can I place an order for SMC5K78A-M3/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMC5K78A-M3/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 SMC5K78A-M3/H reliable?
The price and inventory of SMC5K78A-M3/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMC5K78A-M3/H is usually 5 days.
3.What payment methods are accepted for SMC5K78A-M3/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMC5K78A-M3/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMC5K78A-M3/H?
SMC5K78A-M3/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMC5K78A-M3/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 SMC5K78A-M3/H?
For technical support, including SMC5K78A-M3/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMC5K78A-M3/H requirements.
6.How does Aetrix verify that SMC5K78A-M3/H is sourced from the original manufacturer or authorized distributors?
All SMC5K78A-M3/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 SMC5K78A-M3/H meets industry standards.
7.What is the process for return or replacement of SMC5K78A-M3/H?
All SMC5K78A-M3/H units undergo pre-shipment inspection (PSI). If there is an issue with SMC5K78A-M3/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 SMC5K78A-M3/H part is unused and in its original packaging.
Return procedure for SMC5K78A-M3/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMC5K78A-M3/H Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
Comparator circuit design covering voltage thresholds, input limits, open-collector outputs, LM393 wiring, op-amp differences, hysteresis, timing, window detection and practical fault diagnosis.
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
