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Vishay General Semiconductor - Diodes Division SA78A-E3/54
- Part No.:
- SA78A-E3/54
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA78A-E3/54.pdf
- Description:
- TVS DIODE 78VWM 126VC DO204AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,956
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Product details
Overview
SA78A-E3/54 from Vishay General Semiconductor is a unidirectional Transient Voltage Suppressor (TVS) diode in DO-15 package, designed for 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, 126 V clamping voltage (VC) at 4 A peak pulse current, and 500 W peak pulse power rating with 10/1000 µs waveform - deployed on power rails and I/O lines in industrial motor drives.
For engineers reviewing the SA78A-E3/54 datasheet, SA78A-E3/54 pinout, SA78A-E3/54 application, or SA78A-E3/54 equivalent, this page delivers verified electrical parameters, DO-15 terminal polarity mapping, AEC-Q101 qualification status, thermal derating curves, and real-world clamping performance data under standardized surge conditions.
Technical Context
The SA78A-E3/54 operates as a unidirectional avalanche diode with glass-passivated junction, optimized for fast response (<1 ps) to transient events such as inductive switching spikes and ESD. Its 78 V stand-off allows stable operation across 24 V and 48 V DC systems while maintaining low leakage (<1 µA at VWM) and low incremental surge resistance.
It complies with JEDEC JESD22-B106 (solder dip 275 °C/10 s), JESD201 Class 1A whisker testing, and AEC-Q101 stress requirements. Thermal performance is defined up to TJ = 175 °C, with steady-state power dissipation rated at 3.0 W on infinite heatsink at TL = 75 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - maximum continuous reverse operating voltage before clamping begins; sets system-level overvoltage trip threshold |
| VBR (min/max) | 86.7 V / 95.8 V at IT = 1 mA - defines guaranteed avalanche onset range for design margining |
| VC @ IPPM | 126 V at 4 A - clamping voltage during 10/1000 µs surge; determines protected circuit's maximum transient exposure |
| PPPM | 500 W - peak pulse power handling capability; enables robust protection against IEC 61000-4-5 Level 3 surges |
| IFSM | 70 A - non-repetitive forward surge current rating; supports high-energy fault clearing in power supply inputs |
| TJ max. | 175 °C - maximum junction temperature; ensures reliability in enclosed industrial enclosures without active cooling |
| Package | DO-15 (DO-204AC) - industry-standard axial leaded package with UL 94 V-0 molded epoxy housing |
Pinout & Package
DO-15 (DO-204AC) package with matte tin-plated leads solderable per J-STD-002 and JESD 22-B102; cathode indicated by color band on body end.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (banded end) | Cathode terminal | Connected to protected line; reverse-biased during normal operation; conducts when VLINE exceeds VBR |
| Cathode (non-banded end) | Anode terminal | Typically tied to ground or lower-potential rail; establishes reference for clamping action |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Enables stable, repeatable avalanche characteristics over 1000+ surge cycles without parameter drift |
| 500 W peak pulse power (10/1000 µs) | Supports protection against EN 61000-4-5 combination wave surges up to 2 kV open-circuit / 1 kA short-circuit |
| AEC-Q101 qualified (E3 suffix) | Validated for automotive-grade reliability including temperature cycling, HTRB, and mechanical shock per AEC standard |
| Low clamping ratio (VC/VBR ≈ 1.33) | Minimizes voltage overshoot during transients, reducing stress on downstream MOSFETs and controllers |
| RoHS-compliant, JESD201 Class 1A whisker tested | Ensures long-term solder joint integrity in high-humidity or thermally cycled environments |
Applications
| Industrial Motor Drives | 48 V Telecom Power Supplies |
|---|---|
Use Scenario: Protection of gate drivers and current-sense amplifiers from flyback voltage spikes generated by IGBT/MOSFET switching in BLDC inverters. IC Role / Device Role / Timing Role: Unidirectional TVS placed between driver output and ground to clamp negative-going transients below -15 V. Use Value: Limits VGS stress on 60 V-rated MOSFETs to <126 V, preventing gate oxide rupture during 500 W surge events. | Use Scenario: Input-stage surge suppression on 48 V DC-DC converter front-end subjected to lightning-induced surges per IEC 61000-4-5. IC Role / Device Role / Timing Role: Primary overvoltage clamp on bulk input rail upstream of PFC stage, triggered within <1 ns of transient onset. Use Value: Clamps 1 kA surge to ≤126 V, allowing downstream fuse coordination and preventing rectifier bridge failure. |
| Automotive Body Control Modules | Programmable Logic Controller I/O Cards |
Use Scenario: Protection of LIN bus transceivers and microcontroller GPIOs against load dump and jump-start transients in 12 V vehicle subsystems. IC Role / Device Role / Timing Role: Unidirectional TVS connected between LIN line and chassis ground, with VWM = 78 V exceeding ISO 16750-2 load dump peak (up to 60 V). Use Value: Survives 100 ms load dump pulses while maintaining <1 µA leakage at 45 V nominal, preserving bus quiescent current budget. | Use Scenario: Field-side protection on digital input modules receiving 24 V DC sensor signals in factory automation cabinets. IC Role / Device Role / Timing Role: Standoff-rated TVS on each isolated input channel, placed before optocoupler input to limit voltage excursion during cable ESD events. Use Value: Clamps 8 kV contact ESD (IEC 61000-4-2) to <126 V, ensuring optocoupler LED survival and signal integrity retention. |
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-E3/52 (Vishay) | Same VWM/VBR/VC, but SMB package (surface-mount); 600 W PPPM; higher thermal resistance (RθJA = 50 °C/W vs. DO-15's ~30 °C/W) | Preferred for space-constrained PCBs; requires reflow-compatible layout; less suitable for high-temperature ambient chassis mounting | Select SMBJ78A-E3/52 when board area is limited and thermal management uses copper pour; retain SA78A-E3/54 for through-hole ruggedness and chassis heat sinking. |
| P6KE78A (Littelfuse) | Same DO-15 package and VWM = 78 V, but lower PPPM = 600 W; VC = 125 V at 4.8 A; no AEC-Q101 qualification | Used in commercial-grade power supplies where automotive qualification is not required; slightly tighter VBR tolerance (±5 % vs. ±6.5 %) | Choose P6KE78A for cost-sensitive non-automotive designs needing identical footprint; use SA78A-E3/54 where AEC-Q101 compliance and extended temperature margin are mandatory. |
Compared with SMBJ78A-E3/52 and P6KE78A, the SA78A-E3/54 offers unique value in through-hole mechanical robustness, validated AEC-Q101 qualification, and optimized thermal path for chassis-mounted industrial installations - making it preferred for high-reliability 24/48 V systems where vibration, thermal cycling, and long service life are critical.
Availability
SA78A-E3/54 is available at Aetrix Electronics and suitable for industrial motor drives, 48 V telecom power supplies, and automotive body control modules requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for SA78A-E3/54 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 passive components with emphasis on reliability, efficiency, and application-specific optimization.
The SAxxA series is part of Vishay's TRANSZORB® TVS portfolio, engineered for high-energy transient suppression in automotive, industrial, and telecom infrastructure - prioritizing low clamping ratio, fast response, and AEC-Q101 compliance.
FAQ
What is the maximum clamping voltage of SA78A-E3/54 under a 10/1000 µs surge?
The SA78A-E3/54 has a maximum clamping voltage (VC) of 126 V at 4 A peak pulse current (IPPM) under the standardized 10/1000 µs waveform. This value is measured per Figure 7 in Vishay Document 88378 and defines the upper voltage limit imposed on protected circuits during surge events. The SA78A-E3/54 maintains this clamping performance across its full operating temperature range.
Is SA78A-E3/54 qualified for automotive applications?
Yes, the SA78A-E3/54 carries the E3 suffix, indicating RoHS compliance and AEC-Q101 qualification per Vishay's ordering nomenclature and datasheet revision 27-Sep-2021. It has passed stress tests including high-temperature reverse bias (HTRB), temperature cycling, and mechanical shock - confirming suitability for automotive body electronics and powertrain auxiliary systems. The SA78A-E3/54 meets all applicable AEC-Q101 requirements as documented in the official Vishay qualification report.
What is the reverse leakage current of SA78A-E3/54 at its rated stand-off voltage?
At VWM = 78 V and TA = 25 °C, the SA78A-E3/54 exhibits a maximum reverse leakage current (ID) of 1.0 µA, as specified in the Electrical Characteristics table on page 2 of Vishay Document 88378. This low leakage ensures minimal power loss in standby mode and preserves signal integrity on high-impedance sensor lines. The SA78A-E3/54 maintains leakage below 5 µA up to 125 °C per derating curves.
Does SA78A-E3/54 have polarity marking, and how is it identified?
Yes, the SA78A-E3/54 is unidirectional and features a cathode band (color stripe) on the body near one lead end, per DO-15 mechanical drawing and Vishay's polarity note on page 1. The banded end is the cathode; the opposite lead is the anode. This marking is visible under standard visual inspection and aligns with JEDEC DO-204AC standards. The SA78A-E3/54 must be mounted with correct polarity to ensure proper clamping function.
What is the peak forward surge current rating for SA78A-E3/54?
The SA78A-E3/54 has a peak forward surge current (IFSM) rating of 70 A for a 10 ms single half-sine wave, as listed in the Maximum Ratings table on page 1 of Vishay Document 88378. This rating applies only to unidirectional operation and supports fault-clearing capability in DC power input stages. The SA78A-E3/54 sustains this surge without parametric shift when mounted per recommended lead length and thermal conditions.
SA78A-E3/54 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-204AC, DO-15, Axial
- 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):
- 4A
- Power - Peak Pulse:
- 500W
- 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:
- DO-204AC (DO-15)
SA78A-E3/54 FAQ
1.How can I place an order for SA78A-E3/54 through Aetrix?
Please submit a Request for Quotation (RFQ) for SA78A-E3/54 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 SA78A-E3/54 reliable?
The price and inventory of SA78A-E3/54 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA78A-E3/54 is usually 5 days.
3.What payment methods are accepted for SA78A-E3/54?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA78A-E3/54 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA78A-E3/54?
SA78A-E3/54 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA78A-E3/54 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 SA78A-E3/54?
For technical support, including SA78A-E3/54 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA78A-E3/54 requirements.
6.How does Aetrix verify that SA78A-E3/54 is sourced from the original manufacturer or authorized distributors?
All SA78A-E3/54 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 SA78A-E3/54 meets industry standards.
7.What is the process for return or replacement of SA78A-E3/54?
All SA78A-E3/54 units undergo pre-shipment inspection (PSI). If there is an issue with SA78A-E3/54, 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 SA78A-E3/54 part is unused and in its original packaging.
Return procedure for SA78A-E3/54:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SA78A-E3/54 Tags
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