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Vishay General Semiconductor - Diodes Division SMF40A-E3-08
- Part No.:
- SMF40A-E3-08
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-219AB
- Datasheet:
-
SMF40A-E3-08.pdf
- Description:
- TVS DIODE 40VWM 64.5VC SMF
- Quantity:
- Payment:
- Shipping:
Inventory:27,110
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Product details
Overview
SMF40A-E3-08 from Vishay Semiconductors is a unidirectional surface-mount ESD protection diode in the SMF (DO-219AB) package, designed for robust 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 (VC), 172 pF typical capacitance at 0 V, and ±30 kV IEC 61000-4-2 ESD immunity - ideal for USB 2.0, HDMI, and industrial sensor interface protection.
For engineers reviewing the SMF40A-E3-08 datasheet, SMF40A-E3-08 pinout, SMF40A-E3-08 application, or SMF40A-E3-08 equivalent, this device is selected for high-reliability ESD hardening of low-capacitance signal paths where clamping performance, AEC-Q101 qualification readiness, and SOD-123W-compatible footprint are critical design constraints.
Technical Context
This diode operates as a single-channel unidirectional TVS, leveraging silicon avalanche technology to clamp transients above its breakdown threshold while maintaining low leakage (<0.1 µA at 40 V) and fast response time enabled by "Low Noise" process design. Its 10/1000 µs waveform rating supports 200 W peak pulse power with 0.01% duty cycle, and it meets IEC 61000-4-5 surge immunity up to 1000 W (8/20 µs).
The SMF40A-E3-08 is thermally optimized for PCB mounting on 3 mm × 3 mm Cu pads (≥40 µm thick), delivering 180 K/W junction-to-ambient thermal resistance and operating across –65 °C to +175 °C - enabling use in automotive under-hood and industrial control environments without derating.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRWM) | 40 V - Maximum continuous reverse voltage before significant leakage; defines safe operating margin below clamping onset. |
| Breakdown Voltage (VBR) | 44.4–49.1 V at 1 mA - Tight tolerance ensures predictable turn-on during ESD events without premature conduction. |
| Clamping Voltage (VC) | 64.5 V at 3.1 A (10/1000 µs) - Limits downstream IC voltage stress during 3.1 A transient surges, protecting 3.3 V/5 V logic interfaces. |
| Capacitance (CD) | 172 pF at 0 V, 1 MHz - Low enough for USB 2.0 (480 Mbps) and CAN FD signal integrity; verified via manufacturer test conditions. |
| ESD Rating | ±30 kV contact / ±30 kV air (IEC 61000-4-2) - Exceeds Level 4 immunity requirements for consumer and industrial end-equipment. |
| Package | DO-219AB (SOD-123W-compatible) - 3.9 × 1.9 × 1.08 mm low-profile outline enables dense routing and automated reflow assembly. |
| Operating Temp. | –65 °C to +175 °C - Supports extended-range applications including automotive powertrain and industrial motor drives. |
Pinout & Package
SMF40A-E3-08 uses the DO-219AB (SOD-123W-compatible) surface-mount package: cathode-marked anode-cathode configuration in a low-profile, molded plastic case with gull-wing leads. Dimensions: 3.9 mm length × 1.9 mm width × 1.08 mm height; weight: 15 mg; MSL level 1 (J-STD-020); RoHS-compliant, lead-free tin terminations.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Input side of protected line | Connected to signal trace requiring ESD protection; referenced to system ground via cathode path during clamping. |
| Cathode (Pin 2) | Ground reference terminal | Must be routed to low-impedance system ground plane; determines clamping reference and defines unidirectional polarity. |
Key Features
| Feature | Design Value |
|---|---|
| 200 W peak pulse power (10/1000 µs) | Enables reliable suppression of repetitive ESD bursts in high-duty-cycle industrial interfaces without thermal runaway. |
| ±30 kV IEC 61000-4-2 ESD immunity | Meets highest severity level for contact and air discharge, eliminating need for secondary protection layers in Class B/C equipment. |
| 172 pF capacitance at 0 V | Preserves signal edge integrity on 480 Mbps USB 2.0 and 100 Mbps Ethernet PHY lines without measurable jitter degradation. |
| AEC-Q101 qualification available | Supports automotive-grade sourcing pathways; SMF40A-E3-08 shares qualification basis with AEC-Q101-qualified variants in same family. |
| Low incremental surge resistance | Minimizes voltage overshoot during fast-rising transients (e.g., 0.7–1 ns rise time per IEC 61000-4-2), improving clamping precision. |
Applications
| USB 2.0 Data Lines | HDMI DDC/CEC Channels |
|---|---|
Use Scenario: Protecting differential USB 2.0 D+/D− traces 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: 172 pF capacitance avoids signal integrity loss at 480 Mbps; 64.5 V clamping prevents damage to 3.3 V transceiver I/O cells. |
Use Scenario: Safeguarding HDMI DDC (I²C) and CEC control lines against user-handling ESD in home theater AV receivers. IC Role / Device Role / Timing Role: Standalone ESD clamp on bidirectional 5 V control bus, grounded to chassis via short trace. Use Value: 40 V VRWM accommodates 5 V logic swing with margin; ±30 kV rating exceeds IEC 61000-4-2 Level 4 requirement. |
| Automotive Sensor Interfaces | Industrial RS-485 Transceivers |
Use Scenario: Shielding LIN bus or analog sensor outputs (e.g., temperature, pressure) in engine control modules exposed to under-hood ESD. IC Role / Device Role / Timing Role: Point-of-entry protection diode mounted adjacent to connector, referenced to vehicle chassis ground. Use Value: –65 °C to +175 °C operating range matches under-hood thermal profile; AEC-Q101 qualification path supports automotive PPAP. |
Use Scenario: Protecting RS-485 transceiver inputs/outputs in factory automation PLCs subjected to cable-discharge events. IC Role / Device Role / Timing Role: Bidirectional protection implemented using two SMF40A-E3-08 devices in back-to-back configuration. Use Value: 64.5 V clamping limits transceiver rail excursion below absolute maximum ratings; 200 W pulse rating handles long-line surges. |
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 | Higher clamping voltage (69.4 V), larger SMA (DO-214AC) package (4.5 × 2.7 × 2.2 mm), 200 W rating same. | Less suitable for space-constrained USB/HDMI layouts; better for higher-power industrial surge zones. | Select when board layout allows larger footprint and higher clamping is acceptable for 40 V systems. |
| TPD2E001DRYR | 2-channel, 15 pF dual-diode array in USON-6; lower capacitance but 12 V VRWM and 15 kW ESD rating only. | Designed for ultra-high-speed interfaces (e.g., USB 3.0); not rated for 40 V working voltage or 200 W surge. | Choose only for <12 V signal lines requiring sub-20 pF loading; not a functional replacement for SMF40A-E3-08's voltage/surge capability. |
Compared with SMAJ40A-E3/57T and TPD2E001DRYR, SMF40A-E3-08 uniquely balances 40 V stand-off, 64.5 V clamping, 172 pF, and DO-219AB size - making it optimal for compact, high-voltage-signal ESD protection where both electrical margin and board area are constrained.
Availability
SMF40A-E3-08 is available at Aetrix Electronics and suitable for USB 2.0 interface protection, HDMI control channel hardening, and automotive sensor signal conditioning requiring stable component supply and consistent AEC-Q101-aligned quality.
Supply support for SMF40A-E3-08 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 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 high-speed signal line protection with optimized clamping, low capacitance, and AEC-Q101-ready construction - engineered specifically for ESD-hardened interfaces in harsh electromagnetic environments.
FAQ
What is the maximum clamping voltage of SMF40A-E3-08 under standard test conditions?
The SMF40A-E3-08 has a maximum clamping voltage (VC) of 64.5 V when subjected to a 10/1000 µs waveform at 3.1 A peak pulse current. This value is measured per IEC 61000-4-2 and ensures downstream 3.3 V or 5 V ICs remain within safe operating voltage limits during ESD events. The clamping performance is guaranteed across the full operating temperature range.
Is SMF40A-E3-08 qualified to AEC-Q101 for automotive use?
SMF40A-E3-08 is part of the AEC-Q101-qualified SMF family; while the specific -E3-08 variant is RoHS-compliant and built on the same qualified die and process, full AEC-Q101 certification applies to variants marked with "HE3" suffix (e.g., SMF40A-HE3_A08). For automotive PPAP, confirm qualification status with Vishay's official AEC-Q101 certificate for the exact ordering code.
What is the capacitance of SMF40A-E3-08 and how does it affect high-speed signal integrity?
The SMF40A-E3-08 exhibits 172 pF typical capacitance at 0 V and 1 MHz. This value is low enough to avoid measurable signal distortion on USB 2.0 (480 Mbps) and RS-485 (10–20 Mbps) lines, provided trace lengths are kept short and impedance is controlled. It is not recommended for USB 3.0 or PCIe due to bandwidth limitations imposed by this capacitance level.
Can SMF40A-E3-08 be used for bidirectional signal protection?
SMF40A-E3-08 is a unidirectional diode and cannot protect bidirectional signals alone. For bidirectional lines like I²C or RS-485, two SMF40A-E3-08 devices must be connected in series opposition (anode-to-anode or cathode-to-cathode), or a dedicated bidirectional TVS such as SMBJ40CA should be selected instead.
What is the thermal resistance and maximum junction temperature of SMF40A-E3-08?
The SMF40A-E3-08 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. Its maximum junction temperature is 175 °C, supporting operation in under-hood automotive and high-temperature industrial environments without derating under normal ESD event duty cycles.
SMF40A-E3-08 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):
- 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:
- General Purpose
- Capacitance @ Frequency:
- 172pF @ 1MHz
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AB (SMF)
SMF40A-E3-08 FAQ
1.How can I place an order for SMF40A-E3-08 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF40A-E3-08 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 SMF40A-E3-08 reliable?
The price and inventory of SMF40A-E3-08 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF40A-E3-08 is usually 5 days.
3.What payment methods are accepted for SMF40A-E3-08?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF40A-E3-08 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF40A-E3-08?
SMF40A-E3-08 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF40A-E3-08 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 SMF40A-E3-08?
For technical support, including SMF40A-E3-08 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF40A-E3-08 requirements.
6.How does Aetrix verify that SMF40A-E3-08 is sourced from the original manufacturer or authorized distributors?
All SMF40A-E3-08 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 SMF40A-E3-08 meets industry standards.
7.What is the process for return or replacement of SMF40A-E3-08?
All SMF40A-E3-08 units undergo pre-shipment inspection (PSI). If there is an issue with SMF40A-E3-08, 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 SMF40A-E3-08 part is unused and in its original packaging.
Return procedure for SMF40A-E3-08:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF40A-E3-08 Tags
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