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Vishay General Semiconductor - Diodes Division SMF40A-HM3-18
- Part No.:
- SMF40A-HM3-18
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-219AB
- Datasheet:
-
SMF40A-HM3-18.pdf
- Description:
- TVS DIODE 40VWM 64.5VC SMF
- Quantity:
- Payment:
- Shipping:
Inventory:9,593
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Product details
Overview
SMF40A-HM3-18 from Vishay Semiconductors is a unidirectional surface-mount ESD protection diode in DO-219AB (SOD-123W) package, rated for 40 V standoff voltage, 64.5 V maximum clamping voltage at 3.1 A peak pulse current, and 200 W peak pulse power (10/1000 μs). It delivers ±30 kV IEC 61000-4-2 ESD immunity and supports automotive-grade reliability per AEC-Q101.
For engineers reviewing the SMF40A-HM3-18 datasheet, SMF40A-HM3-18 pinout, SMF40A-HM3-18 application, or SMF40A-HM3-18 equivalent, this device is selected for high-speed data line protection in automotive infotainment, USB 2.0 interfaces, and industrial sensor signal conditioning where low capacitance (172 pF), fast response, and robust surge clamping are critical.
Technical Context
This diode operates as a unidirectional transient voltage suppressor (TVS), leveraging silicon avalanche breakdown to clamp reverse transients above VRWM = 40 V while maintaining low leakage (<0.1 μA) below that threshold. Its low incremental surge resistance ensures minimal voltage overshoot during 10/1000 μs surges up to 3.1 A.
The SMF40A-HM3-18 integrates "Low Noise" fast-response technology with sub-nanosecond turn-on, enabling effective suppression of ESD events per IEC 61000-4-2 (±30 kV contact/air) without distorting high-frequency analog or digital signals in protected paths.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRWM) | 40 V - Maximum continuous reverse operating voltage before clamping begins; defines safe operating margin for 3.3 V/5 V/12 V signal lines. |
| Clamping Voltage (VC) | 64.5 V max at IPPM = 3.1 A - Peak voltage seen by protected circuit during worst-case 10/1000 μs surge; ensures downstream ICs remain within absolute max ratings. |
| Peak Pulse Power (PPP) | 200 W (10/1000 μs) - Sustains short-duration energy bursts without failure; sufficient for IEC 61000-4-5 Level 2 surges. |
| Capacitance (CD) | 172 pF at VR = 0 V, f = 1 MHz - Low enough to avoid signal integrity degradation on USB 2.0 or CAN FD lines up to ~10 Mbps. |
| ESD Rating | ±30 kV contact / ±30 kV air per IEC 61000-4-2 - Meets highest industrial and automotive ESD immunity requirements without external shielding. |
| AEC-Q101 Qualified | Yes - Validated for automotive underhood and cabin applications including temperature cycling, humidity, and mechanical shock per AEC standard. |
| Package | DO-219AB (SOD-123W) - 3.9 mm × 1.9 mm × 1.08 mm low-profile outline compatible with automated SMT assembly and reflow profiles up to 260 °C. |
Pinout & Package
SMF40A-HM3-18 uses the DO-219AB (SOD-123W) surface-mount package: cathode-marked anode-cathode configuration with 2 terminals in a single-row, gull-wing leadless outline. Height ≤ 1.08 mm enables use in space-constrained modules.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Input/Line side | Connected to signal line requiring protection; carries surge current into diode during overvoltage event. |
| Cathode (bar-marked end) | Ground reference | Connected to system ground or low-impedance return path; establishes clamping reference and completes transient current path. |
Key Features
| Feature | Design Value |
|---|---|
| 200 W peak pulse power (10/1000 μs) | Enables reliable protection against repetitive ESD and lightning-induced surges in industrial control I/O without thermal runaway. |
| ±30 kV IEC 61000-4-2 ESD immunity | Eliminates need for secondary board-level shielding on exposed ports like USB, HDMI, or sensor connectors in automotive ECUs. |
| AEC-Q101 qualification | Validates long-term reliability under automotive thermal cycling (-65 °C to +175 °C), vibration, and humidity stress for under-hood deployment. |
| 172 pF capacitance at 0 V | Preserves signal rise/fall times on 480 Mbps USB 2.0 differential pairs; avoids jitter or bit errors in high-speed serial links. |
| Low-profile DO-219AB package | Supports 0.5 mm pitch PCB layouts and automated optical inspection (AOI); footprint matches industry-standard SOD-123W land patterns. |
Applications
| Automotive Infotainment Display Interface | Industrial RS-485 Sensor Network |
|---|---|
|
Use Scenario: Protecting LVDS or FPD-Link III video data lines between head unit and TFT display in vehicles exposed to ESD during service or environmental discharge. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed inline on each differential pair to clamp transients before they reach serializer/deserializer ICs. Use Value: Prevents latch-up or permanent damage to display driver ICs during ±30 kV ESD events while adding <200 pF loading to maintain 100+ MHz signal bandwidth. |
Use Scenario: Shielding RS-485 transceivers in factory-floor PLC I/O modules from induced surges due to motor switching or lightning coupling on long cable runs. IC Role / Device Role / Timing Role: Standoff-clamp TVS on A/B bus lines referenced to local ground, absorbing common-mode transients up to 200 W without affecting DC bias. Use Value: Maintains >10 kV surge immunity per IEC 61000-4-5 while preserving bus timing margins via fast <1 ns response and low dynamic impedance. |
| USB 2.0 Host Port Protection | Automotive CAN FD Node Protection |
|
Use Scenario: Safeguarding USB 2.0 D+/D− lines on automotive diagnostic tools or telematics gateways connected to service technicians' laptops. IC Role / Device Role / Timing Role: Dual-channel unidirectional clamping (one diode per line) referenced to ground, suppressing ESD before it reaches USB PHY. Use Value: 172 pF capacitance limits insertion loss to <0.5 dB at 480 MHz, ensuring full-speed USB compliance without retiming or equalization. |
Use Scenario: Protecting CAN FD controller and transceiver pins in ADAS domain controllers subjected to load dump and ESD in 12 V vehicle networks. IC Role / Device Role / Timing Role: Bidirectional-capable unidirectional TVS (cathode to VCC, anode to CANH/CANL) providing asymmetric clamping aligned with CAN bus voltage swing. Use Value: Clamps transients to <65 V while sustaining 175 °C junction temperature-critical for engine bay CAN nodes with no derating required. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ESD protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40A-E3/57T | DO-214AC (SMA) package; 6.5 mm × 4.6 mm × 2.3 mm; 1000 W PPP (8/20 μs); higher clamping (69.4 V @ 5.9 A). | Higher power handling but 3× larger footprint; better for AC mains or PoE port protection, not space-constrained USB or CAN. | Select SMAJ40A-E3/57T only when board area allows and 1000 W surge rating is mandatory; not drop-in for DO-219AB layouts. |
| TPSMF40A | Same DO-219AB package; 64.5 V VC; identical VRWM and capacitance; AEC-Q101 qualified; slightly lower IPPM (3.0 A vs. 3.1 A). | Functionally interchangeable in all automotive and industrial designs; validated for same temperature and humidity profiles. | TPSMF40A is a direct functional alternative with identical mechanical and electrical specs-ideal for dual-sourcing or second-source qualification. |
Compared with SMF40A-HM3-18, SMAJ40A-E3/57T offers higher surge power at the cost of board area and thermal mass, while TPSMF40A provides identical performance in the same footprint-making it the preferred alternative for footprint-consistent redesigns or supply chain diversification.
Availability
SMF40A-HM3-18 is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial RS-485 networks, and USB 2.0 host port protection requiring stable component supply across extended product lifecycles.
Supply support for SMF40A-HM3-18 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 Semiconductors is a global leader in discrete semiconductors, specializing in high-reliability diodes, MOSFETs, optoelectronics, and passive components for automotive, industrial, and computing markets.
The SMF series targets compact, high-performance ESD protection for automotive and industrial signal lines-designed to replace bulkier solutions while meeting AEC-Q101 and IEC 61000-4-2 standards without sacrificing speed or clamping accuracy.
FAQ
What is the maximum clamping voltage of the SMF40A-HM3-18 under a 10/1000 μs surge?
The SMF40A-HM3-18 has a maximum clamping voltage (VC) of 64.5 V at a peak pulse current (IPPM) of 3.1 A with a 10/1000 μs waveform. This value is measured per IEC 61000-4-5 test conditions and ensures protected circuits remain within safe voltage limits during transient events. The SMF40A-HM3-18 maintains this clamping performance across its full operating temperature range of -65 °C to +175 °C.
Is SMF40A-HM3-18 qualified to AEC-Q101, and what does that mean for automotive use?
Yes, SMF40A-HM3-18 is AEC-Q101 qualified, meaning it has passed rigorous stress tests-including temperature cycling, humidity, mechanical shock, and ESD-required for automotive electronic components. This qualification validates its suitability for under-hood and cabin applications such as infotainment, ADAS, and body control modules. The SMF40A-HM3-18 meets these requirements while retaining its 40 V standoff and ±30 kV ESD immunity.
What is the capacitance of SMF40A-HM3-18, and how does it affect high-speed signal lines?
The SMF40A-HM3-18 exhibits 172 pF typical capacitance at 0 V and 1 MHz, measured per manufacturer characterization. This low value minimizes signal distortion and insertion loss on high-speed interfaces such as USB 2.0 (480 Mbps) and CAN FD (up to 5 Mbps), preserving edge integrity and timing margins. The SMF40A-HM3-18 achieves this without compromising clamping performance, making it suitable for data-line protection where bandwidth and ESD robustness are both critical.
Can SMF40A-HM3-18 be used in bidirectional signal protection applications like RS-485 or CAN?
Although SMF40A-HM3-18 is a unidirectional TVS diode, it can protect bidirectional buses like RS-485 or CAN FD when configured with appropriate grounding-e.g., one diode per line referenced to ground, or paired with a second diode for symmetrical clamping. Its 40 V standoff aligns with typical CAN FD common-mode ranges, and its 64.5 V clamping prevents transceiver damage. The SMF40A-HM3-18 is widely deployed in such configurations in automotive and industrial designs.
What is the package type and soldering compatibility of SMF40A-HM3-18?
SMF40A-HM3-18 uses the DO-219AB (SOD-123W) package: 3.9 mm × 1.9 mm × 1.08 mm, with gull-wing–style terminations compatible with standard reflow profiles up to 260 °C peak temperature. It supports wave and reflow soldering per J-STD-020 MSL level 1, and its footprint matches IPC-7351B SOD-123W land patterns. The SMF40A-HM3-18 is optimized for high-yield automated assembly in automotive and industrial manufacturing environments.
SMF40A-HM3-18 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):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 3.1A
- Power - Peak Pulse:
- 200W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- 172pF @ 1MHz
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AB (SMF)
SMF40A-HM3-18 FAQ
1.How can I place an order for SMF40A-HM3-18 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF40A-HM3-18 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 SMF40A-HM3-18 reliable?
The price and inventory of SMF40A-HM3-18 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF40A-HM3-18 is usually 5 days.
3.What payment methods are accepted for SMF40A-HM3-18?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF40A-HM3-18 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF40A-HM3-18?
SMF40A-HM3-18 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF40A-HM3-18 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 SMF40A-HM3-18?
For technical support, including SMF40A-HM3-18 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF40A-HM3-18 requirements.
6.How does Aetrix verify that SMF40A-HM3-18 is sourced from the original manufacturer or authorized distributors?
All SMF40A-HM3-18 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 SMF40A-HM3-18 meets industry standards.
7.What is the process for return or replacement of SMF40A-HM3-18?
All SMF40A-HM3-18 units undergo pre-shipment inspection (PSI). If there is an issue with SMF40A-HM3-18, 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 SMF40A-HM3-18 part is unused and in its original packaging.
Return procedure for SMF40A-HM3-18:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF40A-HM3-18 Tags
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