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Vishay General Semiconductor - Diodes Division SMAJ18CAHE3_A/H
- Part No.:
- SMAJ18CAHE3_A/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ18CAHE3_A/H.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO214AC
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
SMAJ18CAHE3_A/H from Vishay General Semiconductor is a bidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMA (DO-214AC) package, designed for clamping voltage transients on signal and power lines. It features 18 V standoff voltage (VWM), 20.0–22.1 V breakdown voltage (VBR) at 1 mA, 400 W peak pulse power (10/1000 μs), and clamps to ≤29.2 V at 13.7 A peak surge current - deployed in automotive sensor interfaces and industrial I/O protection.
For engineers reviewing the SMAJ18CAHE3_A/H datasheet, SMAJ18CAHE3_A/H pinout, SMAJ18CAHE3_A/H application, or SMAJ18CAHE3_A/H equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification, 150 °C max junction temperature, low incremental surge resistance, and compatibility with automated SMT assembly on 0.2" × 0.2" copper pads.
Technical Context
This TVS diode operates symmetrically in both directions due to its bidirectional construction, enabling protection of AC-coupled or differential signal paths without polarity constraints. Its glass-passivated junction ensures stable VBR over temperature, with ±0.092 %/°C temperature coefficient and 120 °C/W junction-to-ambient thermal resistance under standard pad layout.
The device meets MSL Level 1 per J-STD-020, supports 260 °C lead-free reflow, and delivers 400 W peak pulse power up to 78 V - derated to 300 W above that threshold. It exhibits fast response time (<1 ns), low clamping ratio (VC/VBR ≈ 1.46), and <1.0 μA reverse leakage at 18 V standoff.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - maximum continuous reverse operating voltage before significant leakage; defines safe working range for protected line. |
| VBR (min/max) | 20.0 V / 22.1 V at 1 mA - guaranteed breakdown window; determines earliest clamping onset under transient stress. |
| VC @ IPPM | 29.2 V at 13.7 A - clamped voltage during 10/1000 μs surge; directly limits stress on downstream ICs like microcontrollers or transceivers. |
| PPPM | 400 W (≤78 V), 300 W (>78 V) - peak transient energy handling capacity; validated with 10/1000 μs waveform per ANSI/IEEE C62.35. |
| ID @ VWM | 1.0 μA - reverse leakage at rated standoff; ensures minimal power loss and signal integrity in high-impedance circuits. |
| TJ max. | +150 °C - maximum junction temperature; enables operation in under-hood automotive or industrial environments. |
| Package | SMA (DO-214AC) - industry-standard surface-mount outline; compatible with JEDEC MS-013, supports automated pick-and-place. |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with matte tin-plated leads, UL 94 V-0 rated compound, no polarity marking for bidirectional configuration.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current entry (one direction) | Accepts positive-going surges relative to cathode; forms symmetrical conduction path with cathode in bidirectional mode. |
| Cathode | Transient current entry (opposite direction) | Accepts negative-going surges relative to anode; completes bidirectional clamping loop across protected line pair. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control modules and ADAS sensor interfaces per stress test requirements. |
| 400 W peak pulse power (10/1000 μs) | Withstands ISO 7637-2 Pulse 1/2a/3a and IEC 61000-4-5 surge events without degradation when mounted per recommended pad layout. |
| Low clamping voltage (VC = 29.2 V) | Provides 11.2 V margin below typical 40 V absolute maximum rating of 3.3 V/5 V logic ICs, reducing risk of latch-up or gate oxide damage. |
| MSL Level 1, 260 °C reflow compatible | Enables single-pass lead-free assembly without moisture sensitivity concerns or pre-bake requirements. |
| Glass passivated junction | Ensures stable VBR over lifetime and temperature cycling; eliminates parameter drift seen in epoxy-passivated alternatives. |
Applications
| Automotive Sensor Protection | Industrial PLC I/O Protection |
|---|---|
|
Use Scenario: Protecting CAN/LIN bus transceivers and analog sensor inputs (e.g., pressure, temperature) from load dump and inductive switching transients in vehicle ECUs. IC Role / Device Role: Bidirectional clamping element placed between signal line and ground, shunting surge energy away from sensitive interface ICs. Use Value: Maintains signal integrity during 100 V/500 ms load dump events while meeting AEC-Q101 reliability requirements for 15-year service life. |
Use Scenario: Safeguarding digital input channels on programmable logic controllers exposed to relay coil flyback and ESD in factory automation systems. IC Role / Device Role: Primary transient suppressor on 24 V DC input terminals, coordinated with upstream fusing and filtering. Use Value: Limits transient voltage to ≤29.2 V, preventing false triggering or permanent damage to optocoupler input stages and microcontroller GPIOs. |
| Consumer USB Port ESD Protection | Telecom Line Interface Protection |
|
Use Scenario: Secondary-level ESD protection on USB 2.0 D+/D− lines in set-top boxes and smart displays, following primary polymer-based TVS. IC Role / Device Role: Fast-response silicon-based clamp absorbing IEC 61000-4-2 ±15 kV contact discharge energy. Use Value: Achieves sub-1 ns response and <1.0 μA leakage at 5 V, preserving signal rise time and minimizing standby current drain. |
Use Scenario: Overvoltage protection on RS-485/RS-422 differential pairs in base station backhaul equipment subjected to lightning-induced surges. IC Role / Device Role: Bidirectional suppressor bridging differential lines to ground, maintaining common-mode rejection during transients. Use Value: Symmetrical clamping ensures balanced voltage excursion on both A/B lines, avoiding receiver offset or data corruption. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18CA-M3 | Halogen-free, RoHS-compliant variant; identical electrical specs and AEC-Q101 qualification. | No functional difference; selected where halogen-free material compliance is mandated by OEM specifications. | Choose SMAJ18CA-M3 when environmental compliance requires absence of brominated flame retardants. |
| SMBJ18CAHE3_A/H | Same VWM/VBR/VC specs but in larger SMB (DO-214AA) package; 600 W PPPM rating (vs. 400 W). | Higher surge handling supports more severe transients (e.g., ISO 7637-2 Pulse 5a); requires larger PCB area. | Select SMBJ18CAHE3_A/H only when system-level testing confirms need for >400 W surge margin and board space permits SMB footprint. |
Compared with SMAJ18CAHE3_A/H, SMAJ18CA-M3 offers identical protection performance with halogen-free packaging, while SMBJ18CAHE3_A/H trades compact size for higher 600 W surge capacity - making the SMAJ18CAHE3_A/H optimal for space-constrained AEC-Q101 automotive designs requiring verified 400 W robustness.
Availability
SMAJ18CAHE3_A/H is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial PLC I/O protection, consumer USB port ESD hardening, and telecom line interface safeguarding requiring stable component supply across production lifecycles.
Supply support for SMAJ18CAHE3_A/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, MOSFETs, optoelectronics, and passive components with emphasis on reliability and application-specific performance.
The SMAJ series is engineered for high-reliability transient suppression in automotive, industrial, and communications infrastructure - delivering consistent clamping behavior under repetitive surge stress and extended temperature operation.
FAQ
What does the "HE3" suffix indicate in SMAJ18CAHE3_A/H?
The "HE3" suffix denotes RoHS-compliant construction with AEC-Q101 qualification, distinguishing it from commercial-grade E3 variants. SMAJ18CAHE3_A/H is specifically tested and certified for automotive use, including temperature cycling, humidity bias, and mechanical shock per AEC-Q101 standards - critical for deployment in engine control units and ADAS sensors where field failure is unacceptable.
Is SMAJ18CAHE3_A/H unidirectional or bidirectional?
SMAJ18CAHE3_A/H is a bidirectional TVS diode, as confirmed by the "CA" suffix per Vishay's naming convention. It provides symmetrical clamping in both polarities, making it suitable for protecting AC-coupled signals, differential buses (e.g., RS-485), and floating sensor outputs without polarity concerns - unlike unidirectional "A" variants which require correct cathode orientation.
What is the maximum clamping voltage of SMAJ18CAHE3_A/H at rated surge current?
The maximum clamping voltage (VC) of SMAJ18CAHE3_A/H is 29.2 V at 13.7 A peak pulse current (IPPM), measured under standardized 10/1000 μs waveform conditions. This value defines the upper voltage limit imposed on protected circuitry during transient events and is critical for ensuring compatibility with downstream ICs rated for ≤40 V absolute maximum.
Does SMAJ18CAHE3_A/H meet any automotive qualification standards?
Yes, SMAJ18CAHE3_A/H is AEC-Q101 qualified, as explicitly stated in Vishay's datasheet revision 09-Jan-2024. This certification covers stress tests including high-temperature operating life, temperature cycling, and ESD - validating its suitability for automotive powertrain, chassis, and body electronics where long-term reliability under thermal and mechanical stress is mandatory.
What PCB pad layout is recommended for optimal thermal and surge performance of SMAJ18CAHE3_A/H?
Vishay specifies mounting SMAJ18CAHE3_A/H on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal to achieve rated 400 W peak pulse power. Smaller pads reduce heat dissipation and surge current handling, potentially causing thermal runaway during repetitive transients - so adherence to this layout is essential for maintaining datasheet performance in automotive and industrial applications.
SMAJ18CAHE3_A/H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AC, SMA
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 29.2V
- Current - Peak Pulse (10/1000µs):
- 13.7A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ18CAHE3_A/H FAQ
1.How can I place an order for SMAJ18CAHE3_A/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ18CAHE3_A/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 SMAJ18CAHE3_A/H reliable?
The price and inventory of SMAJ18CAHE3_A/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ18CAHE3_A/H is usually 5 days.
3.What payment methods are accepted for SMAJ18CAHE3_A/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ18CAHE3_A/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ18CAHE3_A/H?
SMAJ18CAHE3_A/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ18CAHE3_A/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 SMAJ18CAHE3_A/H?
For technical support, including SMAJ18CAHE3_A/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ18CAHE3_A/H requirements.
6.How does Aetrix verify that SMAJ18CAHE3_A/H is sourced from the original manufacturer or authorized distributors?
All SMAJ18CAHE3_A/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 SMAJ18CAHE3_A/H meets industry standards.
7.What is the process for return or replacement of SMAJ18CAHE3_A/H?
All SMAJ18CAHE3_A/H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ18CAHE3_A/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 SMAJ18CAHE3_A/H part is unused and in its original packaging.
Return procedure for SMAJ18CAHE3_A/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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