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Vishay SMF40A-HM3_A18
- Part No.:
- SMF40A-HM3_A18
- Manufacturer:
- Vishay
- Category:
- TVS Diodes
- Package:
- DO-219AB
- Datasheet:
-
SMF40A-HM3_A18.pdf
- Description:
- ESD PROTECTION DIODE SMF DO219AB
- Quantity:
- Payment:
- Shipping:
Inventory:4,958
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Product details
Overview
SMF40A-HM3_A18 from Vishay Semiconductors is a unidirectional surface-mount ESD protection diode in the SMF (DO-219AB) package, rated for 40 V standoff voltage, 64.5 V maximum clamping voltage at 3.1 A peak pulse current, and ±30 kV IEC 61000-4-2 ESD immunity. It delivers 200 W peak pulse power (10/1000 μs), low 172 pF capacitance at 1 MHz, and AEC-Q101 qualification for automotive electronics.
For engineers reviewing the SMF40A-HM3_A18 datasheet, SMF40A-HM3_A18 pinout, SMF40A-HM3_A18 application, or SMF40A-HM3_A18 equivalent, this device is selected for high-reliability transient suppression in USB 2.0 data lines, automotive infotainment interfaces, and industrial sensor signal conditioning where low clamping voltage and fast response are critical.
Technical Context
The SMF40A-HM3_A18 operates as a single-channel unidirectional TVS diode with cathode-anode polarity, designed to clamp transients above its 44.4 V minimum breakdown voltage while maintaining ≤5 μA leakage at 40 V. Its low incremental surge resistance ensures stable clamping performance under repetitive 10/1000 μs surges up to 200 W.
It leverages Vishay's "Low Noise" technology for sub-nanosecond response time, enabling effective suppression of ESD events per IEC 61000-4-2 (±30 kV contact/air) and surge events per IEC 61000-4-5 (8/20 μs, 1000 W). The device is qualified to AEC-Q101 for automotive underhood and cabin applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRWM) | 40 V - Maximum continuous reverse operating voltage before clamping begins |
| Breakdown Voltage (VBR) | 44.4–49.1 V - Confirmed minimum/maximum reverse breakdown at 1 mA test current |
| Clamping Voltage (VC) | 64.5 V - Maximum voltage seen across terminals during 3.1 A 10/1000 μs transient |
| Peak Pulse Power (PPP) | 200 W - Sustained transient energy handling capability per 10/1000 μs waveform |
| Capacitance (CD) | 172 pF - Measured at 0 V, 1 MHz; suitable for <12 Mbps data lines without signal distortion |
| ESD Rating | ±30 kV - Contact and air discharge per IEC 61000-4-2, 10-pulse test |
| AEC-Q101 Qualified | Yes - Validated for automotive use including temperature cycling, HBM >8 kV, and mechanical robustness |
Pinout & Package
The SMF40A-HM3_A18 uses the DO-219AB (SMF) package: low-profile (1.08 mm max height), SOD-123W-compatible outline, molded UL 94 V-0 compound, MSL level 1, and reflow-solderable with peak temperature ≤260 °C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input/Signal Line Connection | Connected to protected line (e.g., USB D+); conducts during positive transients |
| Cathode | Ground Reference Terminal | Connected to system ground; provides low-impedance path for ESD current dissipation |
Key Features
| Feature | Design Value |
|---|---|
| Fast Response Time | Sub-nanosecond turn-on enables clamping before ESD energy couples into IC inputs |
| Low Clamping Ratio | VC/VBR ≈ 1.45 - Minimizes stress on downstream ICs during surge events |
| Automotive Qualification | AEC-Q101 compliant - Supports deployment in engine control units, ADAS sensors, and infotainment systems |
| Low Capacitance | 172 pF - Preserves signal integrity on high-speed analog and 12 Mbps digital lines |
| Reflow-Compatible Package | DO-219AB footprint - Enables automated assembly without wave soldering limitations |
Applications
| USB 2.0 Interface Protection | Automotive Infotainment Display Port |
|---|---|
Use Scenario: Protecting USB 2.0 D+/D− lines against ESD events in portable diagnostic tools and vehicle telematics modules. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between data line and chassis ground to shunt ESD current away from USB transceiver IC. Use Value: 172 pF capacitance avoids signal rise-time degradation; 64.5 V clamping prevents damage to 3.3 V tolerant PHY inputs. | Use Scenario: Safeguarding LVDS or FPD-Link II video data lanes connecting head unit to center display in vehicles. IC Role / Device Role / Timing Role: Standoff-rated transient suppressor on differential video pairs, referenced to vehicle ground. Use Value: AEC-Q101 qualification ensures reliability over -65 °C to +175 °C ambient; ±30 kV ESD rating meets ISO 10605 requirements. |
| Industrial Sensor Signal Conditioning | RS-485 Communication Port |
Use Scenario: Protecting 4–20 mA current-loop or analog voltage outputs of pressure/temperature sensors in factory automation. IC Role / Device Role / Timing Role: Reverse-biased clamping diode across signal-to-ground to limit induced surges from nearby motor switching. Use Value: 40 V VRWM matches typical 24 V supply rails; 200 W pulse rating handles common 10/1000 μs lightning-induced surges. | Use Scenario: Transient protection on RS-485 bus lines (A/B) in building management systems exposed to long cable runs. IC Role / Device Role / Timing Role: Unidirectional TVS pair (one per line) referenced to local ground to clamp common-mode surges. Use Value: Low 172 pF minimizes impedance mismatch on 120 Ω differential bus; DO-219AB package supports high-density PCB layouts. |
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 | Higher clamping voltage (69.4 V), larger SMA (DO-214AC) package, 200 W rating same | Less suitable for space-constrained USB or FPD-Link designs due to 2.4 mm height vs. SMF's 1.08 mm | Select when board layout allows larger footprint and higher clamping is acceptable for 3.3 V interface margin |
| TPD2E001DRYR | Bi-directional dual-channel array, 15 pF, 5.5 V VRWM - not voltage-compatible with 40 V rail | Designed for low-voltage data lines (e.g., HDMI, I²C), not medium-voltage analog/sensor protection | Choose only for <6 V signal paths requiring ultra-low capacitance; not a functional substitute for SMF40A-HM3_A18 |
Compared with SMAJ40A-E3/5A and TPD2E001DRYR, the SMF40A-HM3_A18 uniquely balances 40 V standoff, ultra-low profile, and automotive qualification-making it optimal for compact, high-reliability 24–48 V system interfaces where board space and environmental robustness are critical.
Availability
SMF40A-HM3_A18 is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial sensor interfaces, and USB 2.0 peripheral protection requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SMF40A-HM3_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 power management, sensing, and protection devices with emphasis on reliability, miniaturization, and automotive-grade qualification.
The SMF series belongs to Vishay's eSMP® family of surface-mount TVS diodes, engineered specifically for high-density PCBs in automotive, industrial, and communications equipment where low profile, high surge capability, and AEC-Q101 compliance are mandatory.
FAQ
What is the maximum clamping voltage of the SMF40A-HM3_A18 under standard test conditions?
The SMF40A-HM3_A18 has a maximum clamping voltage (VC) of 64.5 V when subjected to a 10/1000 μs transient pulse at 3.1 A peak current. This value is measured per IEC 61000-4-5 methodology and reflects worst-case voltage seen by downstream circuitry during surge events, ensuring compatibility with 3.3 V and 5 V interface ICs when properly implemented with appropriate trace inductance.
Is the SMF40A-HM3_A18 suitable for automotive applications?
Yes, the SMF40A-HM3_A18 is AEC-Q101 qualified, tested for human body model (HBM) >8 kV, operating temperature range of -65 °C to +175 °C, and mechanical robustness per automotive standards. Its DO-219AB package and ±30 kV ESD rating make it appropriate for engine control units, ADAS camera links, and infotainment displays where reliability under harsh thermal and electrical conditions is required.
What does the "_A18" suffix indicate in SMF40A-HM3_A18?
The "_A18" suffix denotes tape-and-reel packaging: 10,000 pieces per 13-inch reel on 8 mm carrier tape, with moisture sensitivity level (MSL) 1 handling. This packaging format supports high-volume automated assembly and aligns with Vishay's standard ordering code structure for the SMF series, where "A18" specifies both reel size and tape width.
How does the capacitance of SMF40A-HM3_A18 affect high-speed signal integrity?
The SMF40A-HM3_A18 exhibits 172 pF typical capacitance at 0 V and 1 MHz, which is low enough to avoid significant rise-time degradation on USB 2.0 (480 Mbps) and RS-485 (10 Mbps) signals when placed with short, symmetric traces. Its capacitance rolls off with increasing reverse bias, further reducing loading at nominal operating voltages-enabling reliable use in mixed-signal and data-line protection without compromising bandwidth.
Can SMF40A-HM3_A18 be used in bidirectional signal paths?
No, the SMF40A-HM3_A18 is a unidirectional TVS diode, configured with anode and cathode terminals for single-polarity clamping. It protects only against positive transients on the anode side relative to cathode (ground). For bidirectional protection-such as AC-coupled or differential lines like RS-485-it must be paired with a second device or replaced with a bidirectional variant like SMF40CA-HM3_A18, which is not the same part number and has different marking and electrical behavior.
SMF40A-HM3_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-HM3_A18 FAQ
1.How can I place an order for SMF40A-HM3_A18 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF40A-HM3_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-HM3_A18 reliable?
The price and inventory of SMF40A-HM3_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-HM3_A18 is usually 5 days.
3.What payment methods are accepted for SMF40A-HM3_A18?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF40A-HM3_A18 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF40A-HM3_A18?
SMF40A-HM3_A18 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF40A-HM3_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-HM3_A18?
For technical support, including SMF40A-HM3_A18 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF40A-HM3_A18 requirements.
6.How does Aetrix verify that SMF40A-HM3_A18 is sourced from the original manufacturer or authorized distributors?
All SMF40A-HM3_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-HM3_A18 meets industry standards.
7.What is the process for return or replacement of SMF40A-HM3_A18?
All SMF40A-HM3_A18 units undergo pre-shipment inspection (PSI). If there is an issue with SMF40A-HM3_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-HM3_A18 part is unused and in its original packaging.
Return procedure for SMF40A-HM3_A18:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF40A-HM3_A18 Tags
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Diodes Incorporated
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