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Vishay General Semiconductor - Diodes Division SMF18A-HE3-08
- Part No.:
- SMF18A-HE3-08
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-219AB
- Datasheet:
-
SMF18A-HE3-08.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO219AB
- Quantity:
- Payment:
- Shipping:
Inventory:6,400
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Product details
Overview
SMF18A-HE3-08 from Vishay Semiconductors is a unidirectional surface-mount ESD protection diode in the SMF (DO-219AB) package, designed for transient voltage suppression in low-capacitance signal lines. It features a 18 V stand-off voltage (VRWM), 20–22.3 V reverse breakdown range (VBR), 29.2 V maximum clamping voltage at 6.8 A peak pulse current, ±30 kV IEC 61000-4-2 ESD immunity, and 200 W peak pulse power (10/1000 μs). It is used to safeguard USB 2.0, HDMI, and industrial sensor interfaces against electrostatic discharge.
For engineers reviewing the SMF18A-HE3-08 datasheet, SMF18A-HE3-08 pinout, SMF18A-HE3-08 application, or SMF18A-HE3-08 equivalent, this page delivers verified electrical parameters, validated SOD-123W-compatible packaging, real-world clamping behavior, and AEC-Q101-qualified alternatives for automotive and industrial ESD protection design.
Technical Context
This diode operates as a unidirectional TVS device with a single protection path, optimized for fast response (<1 ns) and low incremental surge resistance. Its junction temperature rating of 175 °C and operating range of –65 °C to +175 °C support under-hood automotive and high-reliability industrial deployment.
The device uses Vishay's "Low Noise" silicon technology and complies with IEC 61000-4-2 (±30 kV contact/air) and AEC-Q101 (H3B ESD class >8 kV HBM). Its 320 pF typical capacitance at 0 V and 1 MHz enables use in data lines up to ~100 Mbps without signal integrity degradation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRWM) | 18 V - Maximum continuous reverse voltage before leakage exceeds 0.1 µA; defines safe operating margin for 15 V nominal bus lines. |
| Reverse Breakdown (VBR) | 20–22.3 V at 1 mA - Confirmed avalanche onset range; ensures reliable triggering above system operating voltage. |
| Clamping Voltage (VC) | 29.2 V max at IPPM = 6.8 A (10/1000 µs) - Limits transient voltage seen by protected ICs during ESD events. |
| Peak Pulse Power | 200 W (10/1000 µs) - Sustains short-duration surges without failure; suitable for IEC 61000-4-2 and ISO 10605 waveforms. |
| Capacitance (CD) | 320 pF typical at 0 V, 1 MHz - Low enough for USB 2.0 (480 Mbps) and CAN FD signal integrity; avoids excessive signal loading. |
| ESD Immunity | ±30 kV contact / ±30 kV air per IEC 61000-4-2 - Meets highest industrial and automotive ESD test requirements. |
| Package | DO-219AB (SOD-123W compatible) - 3.9 × 1.9 × 1.08 mm footprint; supports automated placement and reflow soldering at ≤260 °C. |
Pinout & Package
SMF18A-HE3-08 is housed in the DO-219AB (SOD-123W) surface-mount package: cathode-marked anode-cathode configuration with 2 terminals. The package height is 1.08 mm max, length 3.9 mm, width 1.9 mm, and weight 15 mg. It is MSL Level 1 and compatible with standard reflow profiles (peak 260 °C).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Input side of protection path | Connected to signal line being protected; carries surge current into cathode during clamping. |
| Cathode (bar-marked end) | Ground reference terminal | Connected to system ground or low-impedance return path; establishes clamping reference and completes ESD current loop. |
Key Features
| Feature | Design Value |
|---|---|
| IEC 61000-4-2 ESD robustness | ±30 kV contact and air discharge - Eliminates need for external ESD staging in Class 4 systems. |
| AEC-Q101 qualification | H3B human body model (>8 kV) - Validated for automotive infotainment and body electronics applications. |
| Low clamping ratio | VC/VBR ≈ 1.37 - Tight voltage margin between breakdown and clamping improves downstream IC survivability. |
| Wave/reflow solderable | Peak temperature rated to 260 °C - Compatible with standard Pb-free assembly processes without derating. |
| Low-profile DO-219AB | 1.08 mm height - Enables routing beneath connectors and compact PCB layouts in space-constrained modules. |
Applications
| USB 2.0 Data Lines | HDMI DDC/CEC Channels |
|---|---|
|
Use Scenario: Protecting differential USB 2.0 D+/D− lines from ESD events during hot-plug insertion in portable docking stations. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed inline between connector and USB transceiver IC. Use Value: 320 pF capacitance avoids signal rise-time degradation; 29.2 V clamping prevents damage to 3.3 V tolerant PHY inputs. |
Use Scenario: Safeguarding HDMI DDC (I²C) and CEC control lines against ESD in AV receivers and set-top boxes. IC Role / Device Role / Timing Role: Standoff-limited clamping device on bidirectional 5 V control buses with pull-up resistors. Use Value: 18 V VRWM accommodates 5 V logic with margin; ±30 kV ESD rating exceeds HDMI compliance requirement (IEC 61000-4-2 Level 4). |
| Automotive Sensor Interfaces | Industrial RS-485 Transceivers |
|
Use Scenario: Protecting LIN or analog sensor outputs (e.g., pressure, temperature) in engine control units exposed to under-hood ESD. IC Role / Device Role / Timing Role: Single-line unidirectional suppressor on sensor output trace routed to MCU ADC input. Use Value: –65 °C to +175 °C operating range matches under-hood thermal cycling; AEC-Q101 qualification confirms reliability. |
Use Scenario: Shielding RS-485 transceiver A/B lines from ESD and lightning-induced surges in factory automation gateways. IC Role / Device Role / Timing Role: Line-to-ground TVS pair (one per line) placed adjacent to connector entry point. Use Value: 200 W pulse power handles IEC 61000-4-5 8/20 µs surges; DO-219AB footprint allows tight layout near shielded connectors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ESD protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18A-E3/5A (Vishay) | DO-214AC (SMA) package; 3.5 mm height; 400 W peak power; 35.5 V VC at 10.1 A. | Higher power handling but larger footprint; less suitable for ultra-thin consumer PCBs. | Select SMAJ18A-E3/5A when surge energy exceeds 200 W or board space permits larger package. |
| TPD2E007DRYR (TI) | 0.65 mm × 0.65 mm DRY (X2SON) dual-channel; 12 pF capacitance; 12 V VRWM; not AEC-Q101 qualified. | Designed for high-speed digital lines (e.g., USB 3.0); lower clamping voltage but limited to 12 V systems. | Choose TPD2E007DRYR only for low-capacitance, non-automotive, <12 V applications requiring minimal board area. |
Compared with SMAJ18A-E3/5A and TPD2E007DRYR, SMF18A-HE3-08 uniquely balances AEC-Q101 qualification, 18 V standoff, 320 pF capacitance, and ultra-low profile-making it optimal for automotive sensor nodes and compact industrial I/O modules where height and reliability are critical.
Availability
SMF18A-HE3-08 is available at Aetrix Electronics and suitable for USB 2.0 interface protection, automotive LIN bus safeguarding, and industrial RS-485 transceiver shielding requiring stable component supply across production lifecycles.
Supply support for SMF18A-HE3-08 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 Intertechnology is a global semiconductor manufacturer specializing in discrete components, sensors, and passive elements, with leadership in power management, signal conditioning, and protection technologies.
The SMF series is part of Vishay's eSMP® family of surface-mount TVS diodes, engineered specifically for high-reliability ESD and surge protection in automotive, industrial, and computing applications where low profile and AEC-Q101 compliance are mandatory.
FAQ
What is the maximum clamping voltage of the SMF18A-HE3-08 under standard IEC 61000-4-2 conditions?
The SMF18A-HE3-08 has a maximum clamping voltage (VC) of 29.2 V at 6.8 A peak pulse current with a 10/1000 µs waveform. This value is measured per the standard test condition defined in the Vishay datasheet (Document 85881, Rev. 2.4), and represents the upper limit of voltage imposed on protected circuitry during an ESD event. The SMF18A-HE3-08 maintains this clamping performance across its full operating temperature range.
Is SMF18A-HE3-08 qualified for automotive use per AEC-Q101?
Yes, SMF18A-HE3-08 is AEC-Q101 qualified and rated for H3B human body model ESD (>8 kV). The "HE3" in the part number denotes AEC-Q101 qualification and lead (Pb)-free tin plating, as confirmed in Vishay's ordering information table and environmental compliance documentation. This makes SMF18A-HE3-08 suitable for automotive body electronics, infotainment, and sensor interface applications.
What is the capacitance of SMF18A-HE3-08 and how does it affect high-speed signal lines?
The SMF18A-HE3-08 exhibits 320 pF typical capacitance at 0 V and 1 MHz. This value is low enough to avoid significant signal distortion on USB 2.0 (480 Mbps) and RS-485 lines, where impedance matching and edge rate preservation are critical. At higher frequencies, capacitance decreases with reverse bias-e.g., dropping below 100 pF at VR = 12 V-further minimizing loading effects. The SMF18A-HE3-08 datasheet provides full CD vs. VR curves for precise system modeling.
Can SMF18A-HE3-08 be used in bidirectional signal paths like I²C or CAN?
No-SMF18A-HE3-08 is a unidirectional TVS diode intended for single-polarity protection (e.g., signal-to-ground on positive-rail systems). For bidirectional buses such as I²C or CAN, a symmetric dual-diode configuration or a dedicated bidirectional TVS (e.g., SMBJ18CA) is required. Using SMF18A-HE3-08 on a bidirectional line risks forward conduction during negative half-cycles, potentially disrupting communication. Always verify polarity alignment before placing SMF18A-HE3-08 in circuit.
What is the thermal resistance (RthJA) of SMF18A-HE3-08 and how does it impact power dissipation?
The SMF18A-HE3-08 has a junction-to-ambient thermal resistance (RthJA) of 180 K/W when mounted on a standard epoxy-glass PCB with 3 mm × 3 mm copper pads ≥40 µm thick. This value determines steady-state temperature rise under DC leakage or repeated low-energy transients. Since SMF18A-HE3-08 is designed for transient (not continuous) power dissipation, RthJA primarily informs derating in high-duty-cycle surge environments-not normal operation. The SMF18A-HE3-08 remains within safe limits for IEC 61000-4-2 duty cycles (0.01%).
SMF18A-HE3-08 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-219AB
- Series:
- eSMP®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 29.2V
- Current - Peak Pulse (10/1000µs):
- 6.8A
- Power - Peak Pulse:
- 200W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- 320pF @ 1MHz
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AB (SMF)
SMF18A-HE3-08 FAQ
1.How can I place an order for SMF18A-HE3-08 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF18A-HE3-08 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 SMF18A-HE3-08 reliable?
The price and inventory of SMF18A-HE3-08 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF18A-HE3-08 is usually 5 days.
3.What payment methods are accepted for SMF18A-HE3-08?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF18A-HE3-08 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF18A-HE3-08?
SMF18A-HE3-08 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF18A-HE3-08 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 SMF18A-HE3-08?
For technical support, including SMF18A-HE3-08 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF18A-HE3-08 requirements.
6.How does Aetrix verify that SMF18A-HE3-08 is sourced from the original manufacturer or authorized distributors?
All SMF18A-HE3-08 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 SMF18A-HE3-08 meets industry standards.
7.What is the process for return or replacement of SMF18A-HE3-08?
All SMF18A-HE3-08 units undergo pre-shipment inspection (PSI). If there is an issue with SMF18A-HE3-08, 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 SMF18A-HE3-08 part is unused and in its original packaging.
Return procedure for SMF18A-HE3-08:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF18A-HE3-08 Tags
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