My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SA78AHE3/54
- Part No.:
- SA78AHE3/54
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA78AHE3/54.pdf
- Description:
- TVS DIODE 78VWM 126VC DO204AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,561
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SA78AHE3/54 from Vishay General Semiconductor is a unidirectional TransZORB® transient voltage suppressor diode in DO-15 package, rated for 78 V stand-off voltage (VWM), 86.7–95.8 V breakdown voltage (VBR) at 1 mA, 500 W peak pulse power (10/1000 μs), and AEC-Q101 qualified for automotive use. It protects MOSFETs and ICs against inductive switching transients in engine control units.
For engineers reviewing the SA78AHE3/54 datasheet, SA78AHE3/54 pinout, SA78AHE3/54 application, or SA78AHE3/54 equivalent, key selection criteria include clamping voltage (126 V at 4 A IPPM), low incremental surge resistance, fast response time, and RoHS-compliant matte tin-plated leads meeting J-STD-002 solderability.
Technical Context
The SA78AHE3/54 operates as a unidirectional avalanche clamp with glass-passivated junction, designed to conduct above its breakdown threshold and limit transient voltages across protected circuit nodes. Its 10/1000 μs waveform rating reflects standardized surge immunity testing per REA definitions, and thermal derating follows a linear curve from 3.0 W at TL = 75 °C down to zero at TJ = 175 °C.
It features a maximum clamping voltage of 126 V at 4 A peak pulse current, 1.0 μA max reverse leakage at 78 V, and a temperature coefficient of +95 mV/°C for VBR - enabling predictable voltage shift over automotive temperature ranges (−55 °C to +175 °C).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 78 V - maximum continuous reverse operating voltage before conduction begins |
| VBR min/max | 86.7 V / 95.8 V at 1 mA - defines guaranteed avalanche onset window for design margining |
| VC @ IPPM | 126 V at 4 A - peak clamped voltage during 10/1000 μs surge, directly limiting stress on downstream ICs |
| PPPM | 500 W - surge energy handling capacity under standard 10/1000 μs waveform with 0.01% duty cycle |
| ID @ VWM | 1.0 μA - ultra-low leakage ensures minimal standby power loss in high-impedance sensor interfaces |
| TJ max | +175 °C - supports under-hood automotive deployment without derating in most PCB layouts |
| IFSM | 70 A - single half-sine surge rating (8.3 ms) for short-circuit or load-dump event tolerance |
Pinout & Package
Package: DO-15 (DO-204AC), axial leaded, epoxy-molded, UL 94 V-0 rated. Cathode indicated by color band on body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference node | Connected to ground or low-voltage rail; establishes reference for clamping action |
| Cathode | Protected line input | Connected to signal/power line being protected; conducts when voltage exceeds VBR |
Key Features
| Feature | Design Value |
|---|---|
| Glass passivated chip junction | Enables stable VBR over lifetime and humidity exposure, critical for automotive field reliability |
| AEC-Q101 qualification | Validated for automotive-grade stress tests including HTOL, TC, UHAST, and mechanical shock |
| 500 W peak pulse power (10/1000 μs) | Withstands ISO 7637-2 Pulse 1/2a/3a transients without degradation in typical 12 V systems |
| Matte tin plated leads | Ensures robust solder joint formation per J-STD-002, eliminating intermetallic voiding risk |
| Low clamping ratio (VC/VBR ≈ 1.33) | Minimizes overvoltage overshoot during fast transients, preserving gate oxide integrity in MOSFET drivers |
Applications
| Automotive Engine Control Unit (ECU) | Industrial PLC I/O Module |
|---|---|
Use Scenario: Protection of microcontroller GPIO and CAN transceiver inputs against load dump and inductive kickback from solenoid drivers. IC Role / Device Role / Timing Role: Unidirectional TVS placed between protected signal line and chassis ground, conducting only during negative-going transients. Use Value: Clamps 12 V system transients up to 126 V, preventing latch-up or permanent damage to 5 V tolerant MCU pins. | Use Scenario: Safeguarding 24 V digital input channels from field-wiring induced surges in factory automation cabinets. IC Role / Device Role / Timing Role: Standoff-mode protector on optocoupler input side, absorbing repetitive 10/1000 μs spikes from relay coil de-energization. Use Value: 1.0 μA leakage at 78 V avoids false triggering in high-impedance current-sense circuits. |
| Telecom Power Supply Input | Consumer Appliance Motor Driver |
Use Scenario: Secondary-side DC bus protection in AC/DC adapters exposed to lightning-induced surges via mains coupling. IC Role / Device Role / Timing Role: Fast-response clamp on +48 V output rail, shunting energy before it reaches downstream DC-DC converters. Use Value: 500 W rating handles multiple 10/1000 μs events per minute without thermal runaway. | Use Scenario: Gate drive line protection in BLDC motor inverters where MOSFET turn-off generates >100 V ringing. IC Role / Device Role / Timing Role: Localized clamp at driver IC output, referenced to source node, suppressing dV/dt-induced shoot-through. Use Value: 126 V clamping voltage stays below 150 V MOSFET VDS rating, ensuring safe operation without snubbers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ78A-E3/5T | Same VWM (78 V), lower PPPM (400 W), SMA package (surface-mount) | Lacks AEC-Q101 qualification; not suitable for automotive under-hood use | Select when board space is constrained and automotive qualification is not required |
| 1.5KE78A | Higher VBR (86.7–95.8 V same), identical DO-15 package, but 1.5 kW PPPM and higher VC (129 V) | Designed for higher-energy surges; larger thermal mass increases mounting sensitivity | Choose for industrial equipment requiring higher surge margin beyond ISO 7637-2 compliance |
Compared with SMAJ78A-E3/5T and 1.5KE78A, the SA78AHE3/54 uniquely combines AEC-Q101 qualification, 500 W capability, and DO-15 through-hole reliability - making it optimal for automotive ECU designs where vibration resistance and long-term parametric stability are mandatory.
Availability
SA78AHE3/54 is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC I/O modules, and telecom power supply inputs requiring stable component supply with full traceability and lifecycle continuity.
Supply support for SA78AHE3/54 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, and protection devices with emphasis on reliability and automotive-grade validation.
The SA78AHE3/54 belongs to Vishay's TransZORB® family - engineered specifically for robust transient suppression in harsh environments, with focus on automotive, industrial, and telecom infrastructure applications.
FAQ
What is the clamping voltage of the SA78AHE3/54 at its rated peak pulse current?
The SA78AHE3/54 has a maximum clamping voltage (VC) of 126 V at 4 A peak pulse current (IPPM), measured under the standard 10/1000 μs waveform. This value is critical for determining whether downstream components like microcontrollers or MOSFETs remain within their absolute maximum voltage ratings during surge events. The SA78AHE3/54 maintains this clamping performance across its full operating temperature range.
Is the SA78AHE3/54 qualified for automotive applications?
Yes, the SA78AHE3/54 carries AEC-Q101 qualification, confirming it has passed rigorous stress tests including high-temperature operating life, temperature cycling, and unbiased highly accelerated stress testing. Its HE3 suffix explicitly denotes AEC-Q101 qualification, making the SA78AHE3/54 suitable for under-hood automotive systems such as engine control units and body control modules.
What is the reverse leakage current specification for the SA78AHE3/54 at its stand-off voltage?
The SA78AHE3/54 specifies a maximum reverse leakage current (ID) of 1.0 μA at its 78 V stand-off voltage (VWM) and 25 °C ambient temperature. This low leakage ensures minimal power loss in high-impedance circuits such as sensor bias networks or optocoupler inputs, and remains stable over temperature due to its glass-passivated junction structure.
Does the SA78AHE3/54 have a polarity marking, and how is it identified?
Yes, the SA78AHE3/54 is unidirectional and features a cathode band - a visible color stripe near one end of the DO-15 package - indicating the cathode terminal. This marking aligns with industry-standard diode polarity conventions and must be oriented toward the protected line (e.g., 12 V rail or signal trace), while the anode connects to ground or low-side reference. No marking appears on bidirectional variants.
What packaging format is used for the SA78AHE3/54, and what is its reel quantity?
The SA78AHE3/54 is supplied in 13-inch diameter paper tape and reel format with a base quantity of 4000 units per reel, using package code "54". This packaging supports automated pick-and-place assembly and complies with EIA-481 standards. The "HE3" suffix confirms RoHS compliance and AEC-Q101 qualification, while the tape material and reel labeling meet Vishay's traceability requirements for automotive production.
SA78AHE3/54 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:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AC (DO-15)
SA78AHE3/54 FAQ
1.How can I place an order for SA78AHE3/54 through Aetrix?
Please submit a Request for Quotation (RFQ) for SA78AHE3/54 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 SA78AHE3/54 reliable?
The price and inventory of SA78AHE3/54 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA78AHE3/54 is usually 5 days.
3.What payment methods are accepted for SA78AHE3/54?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA78AHE3/54 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA78AHE3/54?
SA78AHE3/54 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA78AHE3/54 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 SA78AHE3/54?
For technical support, including SA78AHE3/54 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA78AHE3/54 requirements.
6.How does Aetrix verify that SA78AHE3/54 is sourced from the original manufacturer or authorized distributors?
All SA78AHE3/54 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 SA78AHE3/54 meets industry standards.
7.What is the process for return or replacement of SA78AHE3/54?
All SA78AHE3/54 units undergo pre-shipment inspection (PSI). If there is an issue with SA78AHE3/54, 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 SA78AHE3/54 part is unused and in its original packaging.
Return procedure for SA78AHE3/54:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SA78AHE3/54 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 …
