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Vishay General Semiconductor - Diodes Division SMF12A-HM3-18
- Part No.:
- SMF12A-HM3-18
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-219AB
- Datasheet:
-
SMF12A-HM3-18.pdf
- Description:
- TVS DIODE 12VWM 19.9VC SMF
- Quantity:
- Payment:
- Shipping:
Inventory:5,705
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Product details
Overview
SMF12A-HM3-18 from Vishay Semiconductors is a unidirectional surface-mount ESD protection diode in the SMF (DO-219AB) package, designed for low-capacitance transient suppression on high-speed data lines. It features a 12 V stand-off voltage (VRWM), 19.9 V maximum clamping voltage at 10.1 A peak pulse current, 483 pF typical capacitance at 0 V, ±30 kV IEC 61000-4-2 ESD immunity, and AEC-Q101 qualification for automotive applications.
For engineers reviewing the SMF12A-HM3-18 datasheet, SMF12A-HM3-18 pinout, SMF12A-HM3-18 application, or SMF12A-HM3-18 equivalent, this device is selected for robust electrostatic discharge protection in USB 2.0, HDMI, Ethernet PHY interfaces, and automotive infotainment signal lines where low clamping voltage and sub-500 pF capacitance are critical to signal integrity.
Technical Context
The SMF12A-HM3-18 employs a planar junction silicon avalanche diode structure optimized for fast response (<1 ns) and low incremental surge resistance. Its unidirectional configuration provides reverse-biased clamping only, with cathode-anode polarity clearly marked on the SOD-123W-compatible DO-219AB package.
It operates across -65 °C to +175 °C, supports wave and reflow soldering per J-STD-020 MSL level 1, and delivers 200 W peak pulse power (10/1000 μs) with 180 K/W junction-to-ambient thermal resistance on standard 3 mm × 3 mm Cu pads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRWM) | 12 V - Maximum continuous reverse voltage before clamping begins; ensures no leakage during normal 12 V rail or interface operation. |
| Clamping Voltage (VC) | 19.9 V max at 10.1 A - Limits transient voltage to safe levels for downstream 24 V-tolerant receivers or 16 V-rated ICs. |
| Peak Pulse Current (IPPM) | 10.1 A (10/1000 μs) - Withstands IEC 61000-4-5 surge events up to Level 3 (1 kV line-to-ground) in properly decoupled circuits. |
| Capacitance (CD) | 483 pF at 0 V, 1 MHz - Low enough for USB 2.0 (480 Mbps) and CAN FD (5 Mbps) without measurable signal rise-time degradation. |
| ESD Rating | ±30 kV contact / ±30 kV air (IEC 61000-4-2) - Meets highest industrial and automotive ESD immunity requirements without external filtering. |
| AEC-Q101 Qualified | Yes - Validated for automotive underhood and cabin applications including infotainment, ADAS camera links, and body control modules. |
| Package | DO-219AB (SOD-123W footprint) - 3.9 mm × 1.9 mm × 1.08 mm low-profile outline compatible with automated SMT assembly and space-constrained PCB layouts. |
Pinout & Package
SMF12A-HM3-18 uses the DO-219AB (SOD-123W-compatible) surface-mount package: 2-terminal, single-channel unidirectional ESD suppressor. Cathode is marked by a bar on the device top surface. The package is lead (Pb)-free, RoHS-compliant, and rated UL 94 V-0.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Input/Line side | Connected to protected signal line or power rail; conducts surge current toward ground when clamped. |
| Cathode (bar-marked end) | Ground reference | Connected to system ground plane; establishes clamping threshold relative to GND and enables fast turn-on during transients. |
Key Features
| Feature | Design Value |
|---|---|
| Low clamping voltage | 19.9 V max at 10.1 A - Minimizes stress on downstream 24 V logic and analog front-ends during surge events. |
| Fast response time | < 1 ns - Detects and clamps ESD transients before they propagate into sensitive IC inputs (e.g., USB PHY, HDMI TMDS). |
| Automotive-grade reliability | AEC-Q101 qualified - Validated for temperature cycling, humidity bias, and mechanical shock per automotive electronics standards. |
| Low-profile SMT package | DO-219AB (1.08 mm height) - Enables placement adjacent to connectors and high-density BGA ICs without interference or tombstoning risk. |
| High ESD immunity | ±30 kV contact/air - Eliminates need for secondary ESD protection layers in cost-sensitive automotive and industrial designs. |
Applications
| USB 2.0 Data Lines | HDMI DDC/CEC Channels |
|---|---|
Use Scenario: Protecting differential USB 2.0 D+ and D- lines against ESD events during hot-plug insertion in automotive head units and industrial docking stations. IC Role / Device Role / Timing Role: Unidirectional clamping diode placed between each data line and chassis ground, operating as a voltage-triggered shunt path. Use Value: 483 pF capacitance avoids signal integrity loss at 480 Mbps; 19.9 V clamping prevents damage to USB transceivers rated for ≤20 V absolute maximum. |
Use Scenario: Safeguarding HDMI DDC (I²C) and CEC control lines in smart TVs and AV receivers exposed to user-handling ESD. IC Role / Device Role / Timing Role: Standoff-clamp protector on bidirectional 5 V I²C bus lines, leveraging unidirectional behavior with pull-up to 5 V and ground reference. Use Value: 12 V VRWM allows full 5 V logic swing with margin; ±30 kV ESD rating exceeds IEC 61000-4-2 Level 4 requirement for consumer electronics. |
| Automotive Camera Link (FPD-Link III) | Industrial CAN FD Bus Nodes |
Use Scenario: Transient suppression on FPD-Link III serial video lines running from rearview cameras to display processors in vehicles. IC Role / Device Role / Timing Role: High-speed ESD clamp on AC-coupled differential pairs, mounted directly at connector entry point. Use Value: Sub-500 pF capacitance preserves edge fidelity of 3 Gbps serialized video; AEC-Q101 qualification ensures reliability over 15-year vehicle lifetime. |
Use Scenario: Protecting CAN FD transceiver pins (CANH/CANL) in factory automation controllers subjected to cable-discharge events. IC Role / Device Role / Timing Role: Dual-diode configuration (two SMF12A-HM3-18 devices) used in split-rail arrangement for bidirectional line protection. Use Value: 10.1 A IPPM handles ISO 16750-2 pulse 5a surges; 19.9 V clamping stays below CAN FD transceiver breakdown limits (typically 24–36 V). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ESD protection diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SP1003-01WTG | Bi-directional, 12 V VRWM, 25 V VC @ 8 A, 30 pF - lower capacitance but lower surge rating. | Preferred for ultra-high-speed interfaces (e.g., PCIe Gen3) where <50 pF is mandatory; unsuitable for high-energy surges. | Select SP1003-01WTG only when capacitance is the dominant constraint and peak surge energy is ≤100 W. |
| ON Semiconductor SZ1.5SMC12A | Same unidirectional function, 12 V VRWM, 19.9 V VC @ 10.1 A, but in larger DO-214AB (SMC) package (7.1 mm × 6.2 mm). | Used where board space permits and higher thermal mass is needed for repeated surge events; not suitable for dense automotive PCBs. | Choose SZ1.5SMC12A only if layout allows larger footprint and thermal dissipation exceeds DO-219AB limits. |
Compared with SP1003-01WTG and SZ1.5SMC12A, SMF12A-HM3-18 uniquely balances 483 pF capacitance, 10.1 A surge capability, and 3.9 mm × 1.9 mm footprint-making it optimal for space-constrained automotive and industrial data-line protection where both speed and ruggedness matter.
Availability
SMF12A-HM3-18 is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial fieldbus nodes, and high-speed consumer interface designs requiring stable component supply, long-term lifecycle support, and AEC-Q101 compliance.
Supply support for SMF12A-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 Intertechnology is a global manufacturer of discrete semiconductors and passive components, specializing in high-reliability solutions for automotive, industrial, and computing markets.
The SMF series is part of Vishay's eSMP® family of surface-mount ESD suppressors, engineered specifically for high-speed data line protection in automotive and industrial environments where low capacitance, fast response, and AEC-Q101 validation are mandatory.
FAQ
What is the maximum clamping voltage of the SMF12A-HM3-18 under standard test conditions?
The SMF12A-HM3-18 has a maximum reverse clamping voltage (VC) of 19.9 V when subjected to a 10.1 A peak pulse current with a 10/1000 μs waveform. This value is measured per IEC 61000-4-5 and guarantees that downstream circuitry sees no more than 19.9 V during surge events, protecting 24 V-tolerant ICs and interfaces. The SMF12A-HM3-18 maintains this clamping performance across its full operating temperature range of -65 °C to +175 °C.
Is SMF12A-HM3-18 suitable for bidirectional signal lines like I²C or USB D+/D-?
SMF12A-HM3-18 is a unidirectional ESD suppressor, meaning it clamps only in reverse bias - ideal for lines referenced to ground with a positive supply (e.g., 5 V I²C pull-ups). For true bidirectional protection, two SMF12A-HM3-18 devices can be placed in series opposition (anode-to-anode or cathode-to-cathode), a common practice validated in Vishay application notes for USB and HDMI. The SMF12A-HM3-18 itself does not provide symmetrical clamping without such configuration.
Does SMF12A-HM3-18 meet automotive qualification standards?
Yes, SMF12A-HM3-18 is AEC-Q101 qualified, having passed stress tests including temperature cycling, high-temperature operating life, and ESD robustness per automotive electronics requirements. Its DO-219AB package, 175 °C max junction temperature, and ±30 kV IEC 61000-4-2 rating make it suitable for engine bay, infotainment, and ADAS subsystems. The "HM3" in SMF12A-HM3-18 denotes AEC-Q101 qualification per Vishay's ordering nomenclature.
What is the capacitance of SMF12A-HM3-18 and how does it affect high-speed interfaces?
The SMF12A-HM3-18 exhibits 483 pF typical junction capacitance at 0 V and 1 MHz. This value is low enough to avoid measurable signal distortion on USB 2.0 (480 Mbps) and CAN FD (5 Mbps) buses, where impedance matching and rise-time preservation are critical. At higher frequencies (e.g., HDMI TMDS >1 GHz), capacitance becomes more impactful - in those cases, lower-C alternatives like SP1003-01WTG may be preferred, though with reduced surge handling. The SMF12A-HM3-18 strikes a deliberate balance for mid-speed automotive and industrial data links.
Can SMF12A-HM3-18 be used in place of older SMAJ12A or SMBJ12A devices?
SMF12A-HM3-18 is not a direct drop-in replacement for SMAJ12A (DO-214AC) or SMBJ12A (DO-214AA) due to its smaller DO-219AB package and different thermal profile. While electrical parameters (VRWM = 12 V, VC = 19.9 V) align closely, the SMF12A-HM3-18 has higher power density and lower thermal resistance per unit area. Layout redesign is required - pad dimensions must match the 3.9 mm × 1.9 mm footprint and 1.08 mm height. The SMF12A-HM3-18 offers superior ESD immunity (±30 kV vs. ±20–25 kV) and AEC-Q101 qualification not found in legacy SMAJ/SMBJ series.
SMF12A-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):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 19.9V
- Current - Peak Pulse (10/1000µs):
- 10.1A
- Power - Peak Pulse:
- 200W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- 483pF @ 1MHz
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AB (SMF)
SMF12A-HM3-18 FAQ
1.How can I place an order for SMF12A-HM3-18 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF12A-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 SMF12A-HM3-18 reliable?
The price and inventory of SMF12A-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 SMF12A-HM3-18 is usually 5 days.
3.What payment methods are accepted for SMF12A-HM3-18?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF12A-HM3-18 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF12A-HM3-18?
SMF12A-HM3-18 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF12A-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 SMF12A-HM3-18?
For technical support, including SMF12A-HM3-18 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF12A-HM3-18 requirements.
6.How does Aetrix verify that SMF12A-HM3-18 is sourced from the original manufacturer or authorized distributors?
All SMF12A-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 SMF12A-HM3-18 meets industry standards.
7.What is the process for return or replacement of SMF12A-HM3-18?
All SMF12A-HM3-18 units undergo pre-shipment inspection (PSI). If there is an issue with SMF12A-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 SMF12A-HM3-18 part is unused and in its original packaging.
Return procedure for SMF12A-HM3-18:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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