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Vishay General Semiconductor - Diodes Division 1N6278A-E3/51
- Part No.:
- 1N6278A-E3/51
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-201AA, DO-27, Axial
- Datasheet:
-
1N6278A-E3/51.pdf
- Description:
- TVS DIODE 17.1VWM 27.7VC 1.5KE
- Quantity:
- Payment:
- Shipping:
Inventory:6,460
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Product details
Overview
1N6278A-E3/51 from Vishay General Semiconductor is a unidirectional Transient Voltage Suppressor (TVS) diode designed for primary overvoltage protection in DC power rails and signal lines. It features a 19.0 V to 21.0 V breakdown voltage (VBR) at 1.0 mA test current, 17.1 V maximum standoff voltage (VWM), 27.7 V clamping voltage (VC) at 54.2 A peak pulse current, and 1500 W peak pulse power rating with 10/1000 µs waveform - used to safeguard MOSFETs, ICs, and sensor interfaces against lightning-induced surges and inductive switching transients.
For engineers reviewing the 1N6278A-E3/51 datasheet, 1N6278A-E3/51 pinout, 1N6278A-E3/51 application, or 1N6278A-E3/51 equivalent, this device delivers verified clamping performance, RoHS-compliant matte tin-plated leads, JEDEC 1.5KE package compatibility, and AEC-Q101 qualification options (HE3 suffix variants) - critical for automotive, industrial, and telecom surge protection design validation.
Technical Context
This unidirectional TVS diode operates as a voltage-clamped shunt protector: when transient voltage exceeds VBR, it avalanches into low-impedance conduction, diverting surge current away from downstream circuitry. Its glass-passivated junction ensures stable breakdown characteristics and low incremental surge resistance.
It responds within <1 ns to transients, clamps at 27.7 V under 54.2 A (10/1000 µs), and maintains thermal stability up to 175 °C junction temperature. The 75 °C/W junction-to-ambient thermal resistance supports operation without forced cooling in standard PCB layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/max) | 19.0 V / 21.0 V at 1.0 mA - defines precise avalanche initiation threshold for reliable overvoltage detection |
| VWM | 17.1 V - maximum continuous reverse operating voltage before leakage rises above 1.0 µA |
| VC @ IPPM | 27.7 V at 54.2 A - clamping voltage during full 1500 W surge, limiting protected circuit stress |
| PPPM | 1500 W - peak pulse power handling capability with 10/1000 µs waveform, enabling robust lightning strike immunity |
| IFSM | 200 A - non-repetitive forward surge current rating (8.3 ms half-sine), supporting high-energy inductive kickback absorption |
| TJ max. | +175 °C - extended junction temperature range allows deployment in under-hood automotive and industrial environments |
| RθJA | 75 °C/W - thermal resistance enables natural convection cooling on standard FR-4 PCBs without heatsinking |
Pinout & Package
Package: JEDEC 1.5KE molded epoxy case (Case Style 1.5KE), axial leaded, RoHS-compliant matte tin plating, UL 94 V-0 rated molding compound. Cathode indicated by color band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry / Surge return path | Connected to ground or low-impedance return in unidirectional configuration; completes clamping loop during transient |
| Cathode | Protected line connection / Avalanche reference | Connected to the line being protected (e.g., +12 V rail); avalanche occurs between cathode and anode when VAK > VBR |
Key Features
| Feature | Design Value |
|---|---|
| Glass passivated junction | Ensures stable, repeatable VBR tolerance (±5 %) and long-term reliability under thermal cycling |
| 1500 W peak pulse power (10/1000 µs) | Supports IEC 61000-4-5 Level 4 (4 kV) surge immunity without derating in typical layouts |
| <1 ns response time | Clamps before sensitive CMOS inputs or gate oxides experience destructive overvoltage |
| AEC-Q101 qualified variants available | Validated for automotive powertrain and body electronics per stress test requirements (HTOL, TC, HTRB) |
| Low incremental surge resistance | Minimizes VC overshoot during fast-rising transients (e.g., ESD, relay bounce) |
Applications
| Automotive Power Supply Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Protecting 12 V battery-fed ECUs from load dump (ISO 7637-2 Pulse 5a) and alternator transients. IC Role / Device Role / Timing Role: Unidirectional shunt clamping device placed between VBAT and chassis ground. Use Value: Clamps to 27.7 V during 54.2 A surge, preventing MOSFET gate oxide rupture and MCU brownout in engine control modules. |
Use Scenario: Shielding 4–20 mA current-loop transmitters from field wiring surges in factory automation. IC Role / Device Role / Timing Role: Line-side TVS connected across input terminals of analog front-end ICs. Use Value: Limits induced lightning transients (<100 ns rise) to safe levels before they reach precision op-amps and ADCs. |
| Telecom DC Feeder Protection | Consumer Power Adapter Output Protection |
Use Scenario: Safeguarding PoE-powered equipment (IEEE 802.3af/at) from longitudinal surges on twisted-pair cables. IC Role / Device Role / Timing Role: Paired unidirectional TVS devices on each data pair, referenced to common-mode ground. Use Value: Withstands 1500 W surges while maintaining <17.1 V standby leakage, preserving PoE classification integrity. |
Use Scenario: Secondary-side overvoltage suppression in AC/DC adapters for USB-C PD and smart home hubs. IC Role / Device Role / Timing Role: Final-stage clamp on +5 V or +9 V output rail before connector. Use Value: Prevents damage to connected devices during adapter internal fault conditions (e.g., feedback loop failure). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ20A | DO-214AA package (SMB), 20 V VBR, 300 W PPPM, higher VC/IPPM ratio (32.4 V @ 9.3 A) | Limited to lower-energy surges; unsuitable for IEC 61000-4-5 Level 4 without parallel staging | Select when board space is constrained and surge energy ≤300 W; verify layout thermal relief for SMB footprint |
| 1.5KE20A | Same electrical specs and 1.5KE package; differs only in part numbering convention (Vishay legacy vs. industry-standard prefix) | Identical functional behavior and mounting; no system-level redesign required | Preferred for new designs requiring standardized JEDEC nomenclature; fully interchangeable with 1N6278A-E3/51 in all applications |
Compared with SMBJ20A, 1N6278A-E3/51 delivers 5× higher surge power handling in the same axial-leaded form factor; compared with 1.5KE20A, it shares identical performance but uses Vishay's historical part numbering - both alternatives require no schematic or layout changes when substituting for 1N6278A-E3/51.
Availability
1N6278A-E3/51 is available at Aetrix Electronics and suitable for automotive power distribution, industrial sensor conditioning, telecom DC feeding, and consumer power adapter applications requiring stable component supply, RoHS compliance, and traceable sourcing.
Supply support for 1N6278A-E3/51 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, power efficiency, and AEC-Q qualification.
The 1N6278A-E3/51 belongs to Vishay's TRANSZORB® TVS family, engineered specifically for high-energy transient suppression in harsh environments - targeting automotive, industrial, and infrastructure applications where failure is not acceptable.
FAQ
What is the breakdown voltage tolerance for 1N6278A-E3/51?
The 1N6278A-E3/51 has a specified breakdown voltage range of 19.0 V to 21.0 V at 1.0 mA test current, corresponding to a ±5 % tolerance around the nominal 20 V rating. This tight VBR window ensures consistent clamping onset across production lots and supports predictable system-level surge margin analysis in designs using the 1N6278A-E3/51.
Is 1N6278A-E3/51 suitable for bidirectional transient protection?
No, 1N6278A-E3/51 is a unidirectional TVS diode, intended for DC line protection where polarity is fixed (e.g., +12 V rail to ground). For bidirectional AC or data-line protection, Vishay offers CA-suffixed variants like 1.5KE20CA. Using 1N6278A-E3/51 in reverse-biased AC applications risks permanent failure due to lack of symmetrical avalanche capability.
What is the maximum clamping voltage of 1N6278A-E3/51 under surge conditions?
The 1N6278A-E3/51 clamps to a maximum of 27.7 V when subjected to its rated 54.2 A peak pulse current (10/1000 µs waveform). This value - measured as VC - represents the upper voltage limit imposed on protected circuitry during worst-case surge events, directly determining whether downstream components like 3.3 V logic or 20 V MOSFETs remain within safe operating limits.
Does 1N6278A-E3/51 meet automotive qualification standards?
The base 1N6278A-E3/51 is commercial-grade; however, Vishay offers the AEC-Q101-qualified variant 1N6278AHE3_B (or 1.5KE20AHE3_B) with identical electrical specs. That version undergoes HTOL, temperature cycling, and HTRB testing per AEC-Q101 Rev D, making it suitable for automotive powertrain and body electronics - the 1N6278A-E3/51 itself is not AEC-Q101 certified.
How does the thermal resistance of 1N6278A-E3/51 affect PCB layout?
With a junction-to-ambient thermal resistance (RθJA) of 75 °C/W, the 1N6278A-E3/51 can dissipate its 6.5 W steady-state power without heatsinking on standard 1 oz copper PCBs - provided adequate copper area (≥1 cm² per lead) and minimal trace length. Layouts must avoid thermal isolation; soldering to large copper pours significantly improves sustained surge duty cycle capability for the 1N6278A-E3/51.
1N6278A-E3/51 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-201AA, DO-27, Axial
- Series:
- TransZorb®
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 17.1V
- Voltage - Breakdown (Min):
- 19V
- Voltage - Clamping (Max) @ Ipp:
- 27.7V
- Current - Peak Pulse (10/1000µs):
- 54.2A
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 1.5KE
1N6278A-E3/51 FAQ
1.How can I place an order for 1N6278A-E3/51 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N6278A-E3/51 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 1N6278A-E3/51 reliable?
The price and inventory of 1N6278A-E3/51 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N6278A-E3/51 is usually 5 days.
3.What payment methods are accepted for 1N6278A-E3/51?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N6278A-E3/51 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N6278A-E3/51?
1N6278A-E3/51 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N6278A-E3/51 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 1N6278A-E3/51?
For technical support, including 1N6278A-E3/51 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N6278A-E3/51 requirements.
6.How does Aetrix verify that 1N6278A-E3/51 is sourced from the original manufacturer or authorized distributors?
All 1N6278A-E3/51 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 1N6278A-E3/51 meets industry standards.
7.What is the process for return or replacement of 1N6278A-E3/51?
All 1N6278A-E3/51 units undergo pre-shipment inspection (PSI). If there is an issue with 1N6278A-E3/51, 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 1N6278A-E3/51 part is unused and in its original packaging.
Return procedure for 1N6278A-E3/51:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N6278A-E3/51 Tags
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