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Vishay SMF40A-HE3_A18
- Part No.:
- SMF40A-HE3_A18
- Manufacturer:
- Vishay
- Category:
- TVS Diodes
- Package:
- DO-219AB
- Datasheet:
-
SMF40A-HE3_A18.pdf
- Description:
- ESD PROTECTION DIODE SMF DO219AB
- Quantity:
- Payment:
- Shipping:
Inventory:8,704
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Product details
Overview
SMF40A-HE3_A18 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 (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 USB 2.0, HDMI, and automotive infotainment interfaces.
For engineers reviewing the SMF40A-HE3_A18 datasheet, SMF40A-HE3_A18 pinout, SMF40A-HE3_A18 application, or SMF40A-HE3_A18 equivalent, key selection criteria include clamping voltage under 65 V, sub-175 pF capacitance at 1 MHz, AEC-Q101 qualification status, SOD-123W-compatible footprint, and 200 W peak pulse power handling with 10/1000 μs waveform.
Technical Context
This device operates as a single-channel unidirectional TVS diode, leveraging silicon avalanche technology to clamp transients above its breakdown threshold while maintaining low leakage (<0.1 μA at VRWM). Its low incremental surge resistance ensures rapid voltage stabilization during ESD events, and its "Low Noise" design delivers sub-nanosecond response time critical for protecting high-bandwidth signal paths.
The SMF40A-HE3_A18 is optimized for board-level ESD hardening in compact consumer and automotive electronics, where thermal resistance (RthJA = 180 K/W) and junction temperature range (−65 °C to +175 °C) support reliable operation under reflow soldering and extended environmental stress.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRWM) | 40 V - maximum continuous reverse operating voltage before conduction begins; defines safe signal swing margin for protected line. |
| Reverse Breakdown (VBR) | 44.4–49.1 V at 1 mA - precise avalanche onset range ensuring predictable clamping initiation. |
| Clamping Voltage (VC) | 64.5 V at 3.1 A (10/1000 μs) - peak voltage seen by downstream circuitry during worst-case surge; limits IC damage risk. |
| Capacitance (CD) | 172 pF at 0 V, 1 MHz - low enough for USB 2.0 (480 Mbps) and HDMI 1.4 signal integrity without excessive rise-time degradation. |
| ESD Rating | ±30 kV contact / ±30 kV air per IEC 61000-4-2 - exceeds Level 4 immunity requirements for industrial and automotive end-equipment. |
| Peak Pulse Power | 200 W (10/1000 μs) - sustains short-duration surges common in cable-disconnect and human-handling events. |
| Package | DO-219AB (SOD-123W-compatible) - 3.9 × 1.9 × 1.08 mm low-profile outline enabling dense PCB layouts and automated assembly. |
Pinout & Package
SMF40A-HE3_A18 uses the DO-219AB (SOD-123W-equivalent) surface-mount package with cathode-bar marking on one end. The device has two terminals: anode and cathode, configured for unidirectional transient suppression in series with the protected signal path.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input/Line side | Connected to the signal line requiring protection; conducts during reverse-transient events when cathode is held at higher potential. |
| Cathode | Ground reference side | Connected to system ground or low-impedance return path; establishes clamping reference and enables fast discharge of ESD energy. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including HBM >8 kV and full temperature cycling (-65 °C to +175 °C). |
| Low-profile DO-219AB package | 1.08 mm height enables use in ultra-thin devices such as automotive displays and portable medical sensors. |
| "Low Noise" fast response | Sub-1 ns turn-on time minimizes voltage overshoot during ESD strikes, preserving signal fidelity in high-speed interfaces. |
| Wave and reflow solderable | Compatible with standard Pb-free reflow profiles up to 260 °C peak, supporting J-STD-020 MSL level 1 handling. |
| UL 94 V-0 molding compound | Flame-retardant encapsulation meets safety standards for enclosed consumer and industrial enclosures. |
Applications
| USB 2.0 Data Lines | HDMI 1.4 Interface |
|---|---|
Use Scenario: Protecting D+ and D− differential pairs in portable docking stations against electrostatic discharge during cable insertion. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed in series with each data line, referenced to chassis ground. Use Value: 172 pF capacitance avoids signal integrity degradation at 480 Mbps, while 64.5 V clamping prevents damage to USB PHY transceivers. | Use Scenario: Safeguarding TMDS clock and data channels in automotive head units exposed to ESD during service port access. IC Role / Device Role / Timing Role: Single-channel transient suppressor on each TMDS lane, with cathode tied to low-inductance ground plane. Use Value: ±30 kV IEC 61000-4-2 rating ensures compliance with ISO 10605 for automotive electronics, and DO-219AB footprint supports tight trace routing. |
| Automotive Infotainment | Industrial Sensor Interfaces |
Use Scenario: Shielding CAN FD or LIN bus transceivers from ESD induced via touch-sensitive control panels in vehicle cabins. IC Role / Device Role / Timing Role: Standoff-clamp TVS on bus signal lines, positioned adjacent to connector entry points. Use Value: 40 V VRWM aligns with 12 V automotive supply rails, and −65 °C to +175 °C operating range supports under-hood and cabin deployment. | Use Scenario: Protecting analog sensor outputs (e.g., pressure, temperature) in factory automation modules connected to long cables susceptible to induced transients. IC Role / Device Role / Timing Role: Low-leakage (0.1 μA max) unidirectional suppressor on output lines referenced to local analog ground. Use Value: 180 K/W thermal resistance allows stable operation on small PCB copper pads, and 200 W pulse rating handles field-induced 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 layouts; better for higher-energy surge environments due to higher thermal mass. | Select SMAJ40A-E3/57T only if board area permits larger footprint and higher clamping is acceptable for downstream IC tolerance. |
| TPD2E001DRYR | Bi-directional dual-channel array (2 × 15 pF), 5.5 V VRWM, integrated 10 Ω series resistors, QFN-6 package. | Designed for low-capacitance high-speed interfaces (e.g., USB Type-C); not a direct replacement due to different voltage rating and bidirectional behavior. | Choose TPD2E001DRYR for new designs needing <20 pF capacitance and dual-line protection; avoid for 40 V rail protection. |
Compared with SMF40A-HE3_A18, SMAJ40A-E3/57T offers greater surge robustness but sacrifices board density and clamping performance, while TPD2E001DRYR provides superior high-frequency protection at lower voltages but cannot replace SMF40A-HE3_A18 in 40 V standoff applications.
Availability
SMF40A-HE3_A18 is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial sensor interfaces, and USB/HDMI peripheral designs requiring stable component supply across production lifecycles.
Supply support for SMF40A-HE3_A18 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 board-level ESD protection in space-constrained, high-reliability applications - engineered for AEC-Q101 compliance, low capacitance, and consistent clamping performance across temperature and lifetime.
FAQ
What is the clamping voltage specification for SMF40A-HE3_A18 under standard test conditions?
The SMF40A-HE3_A18 has a maximum reverse 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 61000-4-5 and defines the upper voltage limit imposed on protected circuits during surge events. The clamping performance remains stable across its full operating temperature range of −65 °C to +175 °C, making SMF40A-HE3_A18 suitable for under-hood automotive use.
Is SMF40A-HE3_A18 qualified to AEC-Q101, and what does that qualification cover?
Yes, SMF40A-HE3_A18 is AEC-Q101 qualified, covering stress tests including high-temperature operating life, temperature cycling, mechanical shock, and ESD testing per human body model (HBM Class H3B, >8 kV). This qualification confirms suitability for automotive electronic control units, infotainment systems, and body electronics where reliability under thermal, mechanical, and electrical stress is mandatory. The SMF40A-HE3_A18 datasheet explicitly states AEC-Q101 qualification in the ordering information table.
What is the capacitance of SMF40A-HE3_A18, and how does it affect high-speed signal lines?
The SMF40A-HE3_A18 exhibits a typical capacitance of 172 pF at 0 V and 1 MHz. While this value is higher than ultra-low-capacitance TVS devices, it remains compatible with USB 2.0 (480 Mbps) and HDMI 1.4 (up to 3.4 Gbps) interfaces when used on non-critical or lower-bandwidth lanes. Designers should verify eye diagram integrity and jitter budgets in their specific layout; for higher-speed lanes (e.g., HDMI 2.0+), lower-capacitance alternatives may be preferred. The capacitance of SMF40A-HE3_A18 is confirmed in the Electrical Characteristics table on page 2 of the Vishay document 85881.
Does SMF40A-HE3_A18 support lead-free reflow soldering, and what are the thermal limits?
Yes, SMF40A-HE3_A18 supports lead-free reflow soldering with a peak temperature limit of 260 °C, compliant with J-STD-020 moisture sensitivity level (MSL) 1. Its DO-219AB package uses UL 94 V-0 flame-retardant molding compound and is rated for wave and reflow processes. The device's thermal resistance (RthJA = 180 K/W) is specified for mounting on epoxy-glass PCBs with 3 mm × 3 mm copper pads ≥40 μm thick - critical for managing power dissipation during transient events. These parameters are documented in the Package Data and Absolute Maximum Ratings sections of the SMF40A-HE3_A18 datasheet.
How does the SMF40A-HE3_A18 marking code relate to its electrical specifications?
The marking code for SMF40A-HE3_A18 is "CR", as shown in the Electrical Characteristics table on page 2 of Vishay document 85881. This two-character code uniquely identifies the 40 V variant within the SMF family and corresponds directly to its VBR range (44.4–49.1 V), VRWM (40 V), and VC (64.5 V). The "HE3_A18" suffix denotes AEC-Q101 qualification, RoHS-compliant lead-free terminations, and 10k/reel packaging on 13″ reels. Marking consistency across reels enables traceability and counterfeit mitigation in production environments using SMF40A-HE3_A18.
SMF40A-HE3_A18 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-HE3_A18 FAQ
1.How can I place an order for SMF40A-HE3_A18 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF40A-HE3_A18 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-HE3_A18 reliable?
The price and inventory of SMF40A-HE3_A18 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF40A-HE3_A18 is usually 5 days.
3.What payment methods are accepted for SMF40A-HE3_A18?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF40A-HE3_A18 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF40A-HE3_A18?
SMF40A-HE3_A18 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF40A-HE3_A18 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-HE3_A18?
For technical support, including SMF40A-HE3_A18 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF40A-HE3_A18 requirements.
6.How does Aetrix verify that SMF40A-HE3_A18 is sourced from the original manufacturer or authorized distributors?
All SMF40A-HE3_A18 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-HE3_A18 meets industry standards.
7.What is the process for return or replacement of SMF40A-HE3_A18?
All SMF40A-HE3_A18 units undergo pre-shipment inspection (PSI). If there is an issue with SMF40A-HE3_A18, 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-HE3_A18 part is unused and in its original packaging.
Return procedure for SMF40A-HE3_A18:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF40A-HE3_A18 Tags
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