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Vishay SMF40A-HM3_A08
- Part No.:
- SMF40A-HM3_A08
- Manufacturer:
- Vishay
- Category:
- TVS Diodes
- Package:
- DO-219AB
- Datasheet:
-
SMF40A-HM3_A08.pdf
- Description:
- ESD PROTECTION DIODE SMF DO219AB
- Quantity:
- Payment:
- Shipping:
Inventory:9,399
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Product details
Overview
SMF40A-HM3_A08 from Vishay Semiconductors is a unidirectional surface-mount ESD protection diode in the SMF (DO-219AB) package, designed for transient voltage suppression in high-speed data lines. It features a 40 V stand-off voltage (VRWM), 44.4–49.1 V reverse breakdown range (VBR), 64.5 V maximum clamping voltage at 3.1 A peak pulse current, and ±30 kV IEC 61000-4-2 ESD immunity - deployed in automotive infotainment USB interfaces to safeguard USB 2.0 signal integrity.
For engineers reviewing the SMF40A-HM3_A08 datasheet, SMF40A-HM3_A08 pinout, SMF40A-HM3_A08 application, or SMF40A-HM3_A08 equivalent, key selection criteria include clamping performance under 10/1000 μs surge, low capacitance (172 pF at 0 V), AEC-Q101 qualification status, and SOD-123W-compatible footprint compatibility for board-level ESD hardening.
Technical Context
This device operates as a single-channel unidirectional TVS diode with cathode-anode polarity, optimized for low-inductance PCB layout in high-frequency signal paths. Its "Low Noise" technology ensures sub-nanosecond response time, enabling effective suppression of ESD transients without distorting 480 Mbps USB 2.0 waveforms.
The SMF40A-HM3_A08 leverages silicon avalanche structure with controlled junction design to achieve stable clamping across -65 °C to +175 °C operating range and 175 °C junction temperature limit. It complies with IEC 61000-4-5 (8/20 μs, 1000 W) and IEC 61000-4-2 (±30 kV contact/air), meeting automotive-grade reliability per AEC-Q101 Class H3B (>8 kV HBM).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRWM) | 40 V - maximum continuous reverse voltage before leakage exceeds 0.1 μA; defines safe operating margin below system rail |
| Clamping Voltage (VC) | 64.5 V at IPPM = 3.1 A (10/1000 μs) - limits downstream IC stress during surge events |
| Capacitance (CD) | 172 pF at VR = 0 V, f = 1 MHz - low enough for USB 2.0 (480 Mbps) signal integrity preservation |
| ESD Rating | ±30 kV contact / ±30 kV air per IEC 61000-4-2 - exceeds automotive OEM ESD requirements |
| Package | DO-219AB (SOD-123W-compatible) - 3.9 × 1.9 × 1.08 mm low-profile footprint for space-constrained routing |
| AEC-Q101 Qualified | Yes - validated for automotive applications including infotainment, body control, and ADAS sensor interfaces |
| Thermal Resistance (RthJA) | 180 K/W on 3 mm × 3 mm Cu pads - enables reliable power dissipation in compact layouts |
Pinout & Package
SMF40A-HM3_A08 uses the DO-219AB (SMF) package: a 2-terminal surface-mount device with cathode marked by a bar on the top surface. The package measures 3.9 mm length × 1.9 mm width × 1.08 mm height and is compatible with standard SOD-123W reflow profiles (peak 260 °C).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input side for protected line | Connected to signal line (e.g., USB D+); conducts surge current toward ground when clamped |
| Cathode | Ground reference terminal | Connected to system ground plane; provides low-impedance return path for ESD energy dissipation |
Key Features
| Feature | Design Value |
|---|---|
| 200 W Peak Pulse Power (10/1000 μs) | Sustains repeated ESD surges without degradation in USB or CAN FD interfaces |
| Low Incremental Surge Resistance | Enables tighter clamping (64.5 V @ 3.1 A) vs. higher-resistance alternatives, reducing IC stress |
| "Low Noise" Fast Response | Sub-ns switching preserves signal edge integrity in high-speed digital lines up to 480 Mbps |
| Wave & Reflow Solderable | Compatible with standard J-STD-020 MSL Level 1 reflow profiles - no special handling required |
| UL 94 V-0 Molding Compound | Meets flammability safety standards for automotive cabin and engine bay mounting locations |
Applications
| Automotive USB 2.0 Interface Protection | Industrial CAN FD Bus Node |
|---|---|
Use Scenario: Protecting USB 2.0 D+/D− lines in vehicle head units against hot-plug ESD and cable discharge events. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed inline between connector and USB transceiver IC. Use Value: 172 pF capacitance avoids signal rise-time degradation; 64.5 V clamping prevents transceiver latch-up during ±30 kV contact discharge. | Use Scenario: Safeguarding CAN FD physical layer transceivers in factory automation controllers exposed to field wiring ESD. IC Role / Device Role / Timing Role: Standoff-clamp TVS on CANH/CANL differential pair, referenced to chassis ground. Use Value: 40 V VRWM aligns with 12 V automotive supply margin; AEC-Q101 qualification ensures long-term reliability in vibration-prone environments. |
| Medical Patient Monitor Data Port | Consumer Laptop Docking Station |
Use Scenario: ESD hardening of RS-232 or UART debug ports on portable diagnostic equipment used in clinical settings. IC Role / Device Role / Timing Role: Single-line unidirectional suppressor on TX/RX lines, grounded via short trace to earth-referenced shield. Use Value: -65 °C to +175 °C operating range supports sterilization cycles and extended field deployment without derating. | Use Scenario: Protecting Thunderbolt 3/USB-C alternate mode lanes (DP/HDMI) from user-handling ESD during docking/undocking. IC Role / Device Role / Timing Role: Low-capacitance TVS on high-speed differential pairs, placed adjacent to connector with minimized loop area. Use Value: DO-219AB footprint allows placement within 3 mm of connector; 180 K/W RthJA supports thermal stability during multi-pulse ESD testing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ESD protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40A-E3/5A | DO-214AC (SMA) package; 1.9 mm height vs. SMF's 1.08 mm; 69.4 V VC at 3.1 A | Higher profile limits use in ultra-thin consumer devices; same VRWM but looser clamping | Choose SMAJ40A-E3/5A only if legacy SMA footprint reuse is required and height constraint is relaxed. |
| TPD2EUSB30DRYR | Quad-channel, 0.5 pF per line, integrated 5.5 V clamp; QFN-10 package; not AEC-Q101 qualified | Designed for USB 3.0 SuperSpeed (5 Gbps); lacks automotive qualification and high-power surge rating | Choose TPD2EUSB30DRYR for USB 3.x designs needing ultra-low capacitance, not for automotive or high-energy surge scenarios. |
Compared with SMAJ40A-E3/5A and TPD2EUSB30DRYR, SMF40A-HM3_A08 uniquely balances AEC-Q101 compliance, 64.5 V tight clamping, 172 pF bandwidth suitability for USB 2.0, and ultra-low 1.08 mm profile - making it optimal for space- and reliability-critical automotive data interfaces.
Availability
SMF40A-HM3_A08 is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial CAN FD nodes, and medical patient monitor data ports requiring stable component supply across extended product lifecycles.
Supply support for SMF40A-HM3_A08 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 passive and protection components for automotive, industrial, and computing markets.
The SMF series targets high-speed interface protection in harsh environments, with design focus on AEC-Q101 qualification, low clamping voltage, and SOD-123W footprint compatibility for seamless integration into next-generation automotive ECUs and industrial gateways.
FAQ
What is the clamping voltage specification for SMF40A-HM3_A08 under standard surge conditions?
The SMF40A-HM3_A08 has a maximum reverse clamping voltage (VC) of 64.5 V when subjected to a 10/1000 μs waveform with a peak pulse current (IPPM) of 3.1 A. This value is measured per IEC 61000-4-5 test conditions and reflects the actual voltage seen by downstream circuitry during surge events - critical for ensuring protected ICs remain within absolute maximum ratings. The SMF40A-HM3_A08 achieves this while maintaining low incremental resistance for consistent performance across temperature.
Is SMF40A-HM3_A08 qualified to AEC-Q101, and what does that qualification cover?
Yes, SMF40A-HM3_A08 is AEC-Q101 qualified, covering stress tests including human body model (HBM) >8 kV, temperature cycling, high-temperature operating life, and unbiased highly accelerated stress testing. This qualification confirms suitability for automotive applications such as infotainment, body control modules, and ADAS sensor interfaces where long-term reliability under thermal and mechanical stress is mandatory. The SMF40A-HM3_A08 meets all requirements per Rev. 2.4 of the Vishay SMF family datasheet (Document Number: 85881).
How does the 172 pF capacitance of SMF40A-HM3_A08 impact high-speed signal integrity?
The typical junction capacitance of 172 pF at 0 V bias makes SMF40A-HM3_A08 suitable for USB 2.0 (480 Mbps) and CAN FD (5 Mbps) interfaces, where signal rise times are ≥1 ns. At 1 MHz, this capacitance introduces minimal loading; at higher frequencies, its effect remains manageable due to the device's low inductance DO-219AB package and optimized layout recommendations. For USB 3.0 or PCIe, lower-capacitance alternatives would be preferred - but SMF40A-HM3_A08 delivers optimal trade-off for cost-sensitive, high-reliability USB 2.0 implementations.
What is the package type and soldering compatibility of SMF40A-HM3_A08?
SMF40A-HM3_A08 uses the DO-219AB package (also known as SMF), measuring 3.9 mm × 1.9 mm × 1.08 mm with a cathode bar marking. It is fully compatible with standard wave and reflow soldering processes per J-STD-020, rated for peak temperatures up to 260 °C and classified as MSL Level 1. The package is mechanically and footprint-compatible with SOD-123W, allowing drop-in replacement in existing layouts designed for that outline - confirmed by Vishay's official package comparison documentation.
Can SMF40A-HM3_A08 be used in bidirectional signal protection applications?
No - SMF40A-HM3_A08 is a unidirectional TVS diode, intended for DC-biased lines like automotive 12 V supplies or USB VBUS. For bidirectional protection (e.g., RS-485, CAN, or AC-coupled data lines), a symmetric device such as SMF40CA-HM3_A08 (the complementary bidirectional variant) must be selected. Using SMF40A-HM3_A08 on bidirectional lines risks forward conduction during negative transients, potentially damaging the protected circuit. Always verify polarity alignment per the SMF40A-HM3_A08 cathode marking and application voltage bias.
SMF40A-HM3_A08 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay
- 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 (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AB (SMF)
SMF40A-HM3_A08 FAQ
1.How can I place an order for SMF40A-HM3_A08 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF40A-HM3_A08 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_A08 reliable?
The price and inventory of SMF40A-HM3_A08 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_A08 is usually 5 days.
3.What payment methods are accepted for SMF40A-HM3_A08?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF40A-HM3_A08 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF40A-HM3_A08?
SMF40A-HM3_A08 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF40A-HM3_A08 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_A08?
For technical support, including SMF40A-HM3_A08 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF40A-HM3_A08 requirements.
6.How does Aetrix verify that SMF40A-HM3_A08 is sourced from the original manufacturer or authorized distributors?
All SMF40A-HM3_A08 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_A08 meets industry standards.
7.What is the process for return or replacement of SMF40A-HM3_A08?
All SMF40A-HM3_A08 units undergo pre-shipment inspection (PSI). If there is an issue with SMF40A-HM3_A08, 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_A08 part is unused and in its original packaging.
Return procedure for SMF40A-HM3_A08:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF40A-HM3_A08 Tags
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