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Vishay General Semiconductor - Diodes Division SA18-E3/73
- Part No.:
- SA18-E3/73
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-204AC, DO-15, Axial
- Datasheet:
-
SA18-E3/73.pdf
- Description:
- TVS DIODE 18VWM 32.2VC DO204AC
- Quantity:
- Payment:
- Shipping:
Inventory:3,530
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Product details
Overview
SA18-E3/73 from Vishay General Semiconductor is a unidirectional Transient Voltage Suppressor (TVS) diode in DO-204AC (DO-15) package, designed for primary overvoltage protection of DC power rails and signal lines. It features 18 V stand-off voltage (VWM), 20.0–22.1 V breakdown voltage (VBR at 1 mA), 500 W peak pulse power (10/1000 μs), clamping voltage of 29.2 V at 17.1 A, and AEC-Q101 qualification for automotive-grade reliability.
For engineers reviewing the SA18-E3/73 datasheet, SA18-E3/73 pinout, SA18-E3/73 application, or SA18-E3/73 equivalent, this page delivers verified electrical parameters, polarity marking guidance, clamping performance under surge conditions, thermal derating behavior, and direct alternatives for circuit protection design in automotive ECUs, industrial I/O modules, and power supply front-ends.
Technical Context
The SA18-E3/73 operates as a unidirectional avalanche diode with glass-passivated junction, enabling fast response (<1 ps) to transient events such as ESD, load dump, and inductive switching spikes. Its 10/1000 μs waveform rating reflects standardized surge immunity testing per R.E.A. definitions, and its 175 °C maximum junction temperature supports operation in high-ambient environments like engine compartments.
Clamping behavior is defined by incremental resistance - VC − VBR = 9.2 V at IPPM - and reverse leakage remains ≤1.0 μA at 18 V, ensuring minimal standby power loss. The device's 3.0 W steady-state power dissipation (at TL = 75 °C) and 70 A IFSM rating support robust handling of repetitive surges and single-event overcurrent transients.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - Maximum continuous reverse operating voltage before conduction begins; sets protection threshold for 12 V nominal systems. |
| VBR (min/max) | 20.0 V / 22.1 V at 1 mA - Confirmed breakdown range ensures reliable turn-on margin above VWM without premature triggering. |
| IPPM | 17.1 A - Peak surge current it safely clamps at 10/1000 μs waveform; determines minimum series impedance needed for coordination. |
| VC | 29.2 V - Clamped voltage at IPPM; defines maximum stress imposed on downstream ICs during worst-case transient. |
| PPPM | 500 W - Peak pulse power handling capability; validates suitability for ISO 7637-2 Pulse 1/2a/5a and IEC 61000-4-5 Level 3 surges. |
| TJmax | 175 °C - Maximum junction temperature; enables use in under-hood automotive applications without thermal derating penalties. |
| AEC-Q101 | Qualified - Meets stress test requirements for automotive electronics, including HTOL, TCT, and ESD HBM ≥8 kV. |
Pinout & Package
Package: DO-204AC (DO-15), molded epoxy case with matte tin-plated leads; polarity indicated by cathode band at one end.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry point | Connected to protected line side (e.g., +12 V rail); must be placed upstream of sensitive loads. |
| Cathode (banded end) | Reverse-biased clamping node | Connected to ground or low-impedance return path; provides low-impedance shunt during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR tolerance and long-term reliability under thermal cycling and humidity exposure. |
| 500 W peak pulse power (10/1000 μs) | Supports compliance with automotive transient standards including ISO 7637-2 and SAE J1113-11. |
| AEC-Q101 qualification | Validates suitability for automotive control units, body electronics, and ADAS sensor interfaces without additional qualification effort. |
| Low clamping ratio (VC/VBR ≈ 1.45) | Minimizes voltage overshoot across protected ICs, reducing risk of latch-up or gate oxide damage in MOSFET drivers. |
| RoHS-compliant E3 suffix | Meets JESD 201 Class 1A whisker resistance, enabling use in high-reliability industrial and medical auxiliary circuits. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
|
Use Scenario: Protecting 12 V power inputs in engine control units (ECUs) against load dump transients up to 35 V and ISO 7637-2 Pulse 5a. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between battery feed and LDO input, absorbing energy before it reaches voltage regulators. Use Value: Limits peak voltage to 29.2 V at 17.1 A, preventing regulator shutdown or internal FET failure during 120 V/50 ms load dump events. |
Use Scenario: Safeguarding analog outputs of pressure/temperature sensors in PLC I/O modules exposed to field wiring surges. IC Role / Device Role / Timing Role: Front-end transient suppressor on 4–20 mA loop output, shunting induced spikes before they reach op-amp buffers. Use Value: Sub-30 V clamping ensures sensor output stage remains within absolute maximum ratings even during 4 kV EFT bursts. |
| DC-DC Converter Input Protection | Motor Drive Gate Driver Protection |
|
Use Scenario: Shielding buck converter inputs in telecom power supplies from AC line transients coupled via shared chassis ground. IC Role / Device Role / Timing Role: Primary overvoltage clamp ahead of input filter capacitor and controller IC. Use Value: 500 W pulse rating handles repeated 10/1000 μs surges without degradation, supporting >100,000 surge cycles in field deployment. |
Use Scenario: Protecting high-side gate driver ICs in BLDC motor inverters from shoot-through-induced voltage spikes during commutation. IC Role / Device Role / Timing Role: Localized TVS across gate-source terminals of external MOSFETs, suppressing dv/dt-induced false turn-on. Use Value: Fast <1 ps response time prevents millisecond-scale gate disturbance, maintaining PWM fidelity and torque stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18A-E3/5T | Same DO-214AC (SMA) package; identical VWM (18 V), but lower PPPM (400 W) and higher VC (29.2 V → 32.4 V). | Less suitable for ISO 7637-2 Pulse 5a due to reduced surge margin; preferred where board space constraints favor SMA footprint. | Select SMAJ18A-E3/5T only when layout requires surface-mount and surge energy is limited to ≤400 W. |
| 1.5KE18A | DO-201AD package; same VWM and PPPM, but higher IFSM (100 A vs. 70 A) and larger thermal mass. | Better suited for high-energy industrial surge environments (e.g., factory floor mains coupling), but incompatible with DO-15 footprints. | Choose 1.5KE18A when system-level surge testing exceeds 500 W or when lead-mounted thermal relief is required. |
Compared with SMAJ18A-E3/5T and 1.5KE18A, the SA18-E3/73 offers optimal balance of AEC-Q101 qualification, DO-15 through-hole compatibility, and 500 W surge capacity - making it the preferred choice for automotive and industrial designs requiring proven reliability and legacy board compatibility.
Availability
SA18-E3/73 is available at Aetrix Electronics and suitable for automotive ECU design, industrial I/O protection, and DC-DC converter input safeguarding requiring stable component supply across multi-year production cycles.
Supply support for SA18-E3/73 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, automotive qualification, and application-specific performance.
The SAxxA series was developed specifically for robust transient suppression in harsh environments - targeting automotive power distribution, industrial automation, and telecom infrastructure where failure modes must be mitigated at the component level.
FAQ
What is the polarity configuration of the SA18-E3/73?
The SA18-E3/73 is a unidirectional TVS diode with cathode marked by a visible band on the DO-204AC package. When installed, the banded end connects to ground or reference potential, while the anode connects to the line being protected. This orientation ensures forward conduction only during negative transients - critical for correct operation in DC power rail applications.
Does the SA18-E3/73 meet automotive qualification standards?
Yes, the SA18-E3/73 carries AEC-Q101 qualification, confirmed in Vishay's official documentation (Doc. #88378, Rev. 18-Sep-12). It passes high-temperature operating life (HTOL), temperature cycling (TCT), and human-body model (HBM) ESD tests ≥8 kV - validating its use in automotive control modules, body electronics, and infotainment power supplies without additional qualification.
What is the maximum clamping voltage of the SA18-E3/73 under surge conditions?
The SA18-E3/73 clamps to 29.2 V at its rated peak pulse current of 17.1 A (10/1000 μs waveform). This value is measured per standard test conditions and defines the upper voltage limit imposed on downstream components during transient events - essential for verifying compatibility with 3.3 V or 5 V logic supply rails and MOSFET gate oxide ratings.
Can the SA18-E3/73 replace the SA18A in existing designs?
Yes, SA18-E3/73 is a RoHS-compliant, commercial-grade variant of SA18A with identical electrical specifications and DO-204AC packaging. The "E3" suffix indicates matte tin plating and JESD 201 Class 1A whisker resistance, while "/73" denotes 7-inch tape-and-reel packaging - both fully compatible with SA18A's footprint and function in legacy designs.
How does the SA18-E3/73 perform under elevated ambient temperatures?
The SA18-E3/73 maintains full 500 W peak pulse power capability up to 25 °C ambient; above that, derating follows the curve in Fig. 2 of Vishay Doc. #88378, reaching ~350 W at 85 °C and ~200 W at 125 °C. Its 175 °C TJmax allows continued operation in under-hood environments when PCB layout provides adequate thermal relief via copper pour or lead length optimization.
SA18-E3/73 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-204AC, DO-15, Axial
- Series:
- TransZorb®
- Packaging:
- Tape & Box (TB)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 32.2V
- Current - Peak Pulse (10/1000µs):
- 15.5A
- 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)
SA18-E3/73 FAQ
1.How can I place an order for SA18-E3/73 through Aetrix?
Please submit a Request for Quotation (RFQ) for SA18-E3/73 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 SA18-E3/73 reliable?
The price and inventory of SA18-E3/73 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SA18-E3/73 is usually 5 days.
3.What payment methods are accepted for SA18-E3/73?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SA18-E3/73 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SA18-E3/73?
SA18-E3/73 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SA18-E3/73 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 SA18-E3/73?
For technical support, including SA18-E3/73 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SA18-E3/73 requirements.
6.How does Aetrix verify that SA18-E3/73 is sourced from the original manufacturer or authorized distributors?
All SA18-E3/73 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 SA18-E3/73 meets industry standards.
7.What is the process for return or replacement of SA18-E3/73?
All SA18-E3/73 units undergo pre-shipment inspection (PSI). If there is an issue with SA18-E3/73, 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 SA18-E3/73 part is unused and in its original packaging.
Return procedure for SA18-E3/73:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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