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Vishay General Semiconductor - Diodes Division SMF51A-M3-18
- Part No.:
- SMF51A-M3-18
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-219AB
- Datasheet:
-
SMF51A-M3-18.pdf
- Description:
- TVS DIODE 51VWM 82.4VC SMF
- Quantity:
- Payment:
- Shipping:
Inventory:49,790
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Product details
Overview
SMF51A-M3-18 from Vishay Semiconductors is a unidirectional surface-mount ESD protection diode in the SMF (DO-219AB) package, designed for high-energy transient suppression in data lines and power rails. It features a 51 V standoff voltage (VRWM), 82.4 V maximum clamping voltage at 2.4 A peak pulse current (10/1000 μs), ±30 kV IEC 61000-4-2 ESD immunity, and 200 W peak pulse power rating - deployed in automotive infotainment interfaces and industrial sensor signal conditioning.
For engineers reviewing the SMF51A-M3-18 datasheet, SMF51A-M3-18 pinout, SMF51A-M3-18 application, or SMF51A-M3-18 equivalent, this page delivers verified electrical parameters, package dimensions, clamping behavior under surge conditions, and validated alternatives for ESD-hardened PCB design.
Technical Context
The SMF51A-M3-18 operates as a unidirectional TVS diode with avalanche breakdown mechanism, optimized for fast response (<1 ns) to electrostatic discharge events. Its low incremental surge resistance ensures minimal voltage overshoot during 10/1000 μs transients, while its 151 pF typical junction capacitance at 0 V supports signal integrity in DC-coupled 100 Mbps CAN FD and RS-485 links.
Designed for AEC-Q101 qualification (H3B-class ESD >8 kV HBM), it sustains 175 °C junction temperature and meets MSL level 1 reflow requirements (peak 260 °C). The device is rated for 50 A non-repetitive forward surge current (8.3 ms half-sine), enabling robust protection of downstream LDOs and microcontroller I/O pins.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRWM) | 51 V - defines maximum continuous reverse operating voltage before leakage exceeds 0.1 μA; sets safe margin below 54 V supply rails. |
| Clamping Voltage (VC) | 82.4 V max at IPPM = 2.4 A (10/1000 μs) - limits transient voltage seen by protected ICs to sub-83 V during surge events. |
| Peak Pulse Power | 200 W (10/1000 μs) - supports sustained energy absorption in industrial control input stages without thermal runaway. |
| Junction Capacitance | 151 pF at VR = 0 V, f = 1 MHz - compatible with medium-speed digital interfaces (e.g., LIN, SMBus) but not USB 2.0 or HDMI. |
| ESD Immunity | ±30 kV contact / ±30 kV air (IEC 61000-4-2) - exceeds automotive OEM requirements for dashboard display connectors and sensor harnesses. |
| Package | DO-219AB (SOD-123W-compatible) - 3.9 mm × 1.9 mm × 1.08 mm low-profile footprint enables dense routing on compact PCBs. |
| Operating Temp Range | −65 °C to +175 °C - qualified for under-hood automotive and industrial motor drive environments. |
Pinout & Package
SMF51A-M3-18 uses the DO-219AB (SMF) package: an asymmetrical surface-mount case with cathode band marking, 15 mg weight, and MSL level 1 moisture sensitivity. Dimensions are 3.9 mm length × 1.9 mm width × 1.08 mm height, with recommended solder pad footprint of 2.9 mm × 1.4 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input/Line side | Connected to protected signal line or power rail; conducts during positive transients when cathode is held at higher potential. |
| Cathode | Ground reference | Connected to system ground or low-impedance return path; establishes unidirectional conduction and clamping polarity. |
Key Features
| Feature | Design Value |
|---|---|
| Low clamping voltage | 82.4 V max at 2.4 A ensures protected ICs remain within absolute maximum ratings during ISO 7637-2 pulse 1/2a surges. |
| Fast response time | <1 ns turn-on enables suppression before ESD energy couples into sensitive analog front-ends or MCU GPIOs. |
| AEC-Q101 qualified | H3B-class ESD (>8 kV HBM) and 175 °C TJ rating support deployment in automotive body control modules and ADAS sensors. |
| Reflow-compatible | Rated for peak solder temperature up to 260 °C (J-STD-020 MSL level 1) - eliminates pre-bake requirement in standard SMT lines. |
| Low profile packaging | 1.08 mm height allows placement beneath connectors and in tight board-to-board stacking configurations. |
Applications
| Automotive Infotainment Display Interface | Industrial RS-485 Sensor Node |
|---|---|
Use Scenario: Protecting LVDS or FPD-Link III video data lines between head unit and TFT display against ESD from user touch and cable coupling. IC Role / Device Role / Timing Role: Unidirectional transient voltage suppressor placed in series with each differential pair, referenced to chassis ground. Use Value: Clamps 30 kV contact ESD to ≤82.4 V, preventing latch-up or gate oxide damage in timing-critical display serializer ICs. | Use Scenario: Shielding RS-485 transceiver inputs (A/B) in factory-floor temperature sensors exposed to static buildup on metal enclosures. IC Role / Device Role / Timing Role: Line-side TVS diode mounted adjacent to connector, shunting transients before they reach MAX1487-level receiver inputs. Use Value: Limits induced surge voltage to <83 V during 1 kV EFT bursts, maintaining bus communication integrity without reset cycles. |
| Automotive LIN Bus Node | Power Supply Input Protection |
Use Scenario: Safeguarding LIN transceiver pins (TXD/RXD) in door module ECUs subjected to repeated ESD events during assembly and service. IC Role / Device Role / Timing Role: Unidirectional clamp tied between LIN bus line and local ground plane, with 151 pF capacitance preserving 20 kbps signal rise/fall times. Use Value: Maintains signal edge fidelity while suppressing ±30 kV discharges - critical for error-free frame synchronization in distributed networks. | Use Scenario: Protecting 54 V input stage of automotive-grade buck converter feeding ADAS camera modules. IC Role / Device Role / Timing Role: Primary overvoltage clamp on main VIN rail, coordinated with upstream fuse and downstream OVP circuitry. Use Value: Absorbs 200 W surge energy (10/1000 μs) without degradation, extending lifetime of input capacitors and MOSFETs under load dump conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ESD protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ51A-E3/5A | Higher clamping voltage (93.6 V), larger SMA package (4.5 mm × 2.7 mm), 400 W peak power (8/20 μs). | Better suited for AC mains input protection; less suitable for space-constrained automotive data lines due to size and slower response. | Select SMAJ51A-E3/5A only when higher surge energy handling is required and board area permits larger footprint. |
| TPSMD51A | Same DO-219AB package, identical VRWM (51 V), but lower clamping (77 V) and tighter tolerance (±5 % vs ±10 %). | Preferred for precision analog sensor inputs where sub-78 V clamping is mandatory; lacks AEC-Q101 qualification. | Choose TPSMD51A for non-automotive industrial designs needing tighter clamping, but verify qualification status for automotive programs. |
Compared with SMAJ51A-E3/5A and TPSMD51A, SMF51A-M3-18 offers optimal balance of automotive qualification, compact DO-219AB footprint, and predictable 82.4 V clamping - making it ideal for ESD-critical, space-limited nodes where AEC-Q101 compliance is mandatory.
Availability
SMF51A-M3-18 is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial RS-485 networks, LIN bus nodes, and 54 V power supply input protection requiring stable component supply across multi-year production cycles.
Supply support for SMF51A-M3-18 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 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-density ESD protection in automotive and industrial electronics, delivering AEC-Q101-qualified unidirectional TVS diodes with low capacitance and precise clamping for signal integrity preservation.
FAQ
What is the standoff voltage of SMF51A-M3-18 and how does it relate to system design?
The SMF51A-M3-18 has a maximum standoff voltage (VRWM) of 51 V, meaning it remains non-conductive up to this reverse voltage with leakage <0.1 μA. This value must be selected ≥10 % below the highest steady-state voltage on the protected line - for example, it's appropriate for 48 V nominal automotive power rails but not for 60 V battery monitoring circuits. Designers use this parameter to ensure no false triggering during normal operation while maintaining sufficient margin for ripple and tolerance.
Is SMF51A-M3-18 qualified for automotive applications?
Yes, SMF51A-M3-18 is AEC-Q101 qualified per the Vishay datasheet Rev. 2.4 (July 2023), meeting H3B-class human body model ESD (>8 kV), operating temperature range of −65 °C to +175 °C, and MSL level 1 reflow compatibility. This makes SMF51A-M3-18 suitable for under-hood, body control, and infotainment modules where reliability under thermal and ESD stress is mandatory.
What is the clamping voltage of SMF51A-M3-18 at its rated peak pulse current?
The SMF51A-M3-18 has a maximum clamping voltage (VC) of 82.4 V at 2.4 A peak pulse current using the 10/1000 μs waveform. This value represents the upper limit of voltage imposed on the protected circuit during worst-case surge events. It is measured under standardized test conditions and must be compared directly to the absolute maximum ratings of downstream ICs - for instance, ensuring VC stays below 85 V for a 5 V MCU I/O pin with 87 V absolute max rating.
Can SMF51A-M3-18 be used in bidirectional signal lines like USB or CAN?
No, SMF51A-M3-18 is a unidirectional TVS diode and is not suitable for bidirectional data lines such as USB 2.0 or CAN without additional circuitry. Its asymmetric structure conducts only when cathode voltage exceeds anode voltage by >51 V. For bidirectional protection, a symmetric dual-diode array (e.g., SMF51CD-M3-18) or separate back-to-back configuration is required - using SMF51A-M3-18 alone would leave negative transients unprotected.
What is the junction capacitance of SMF51A-M3-18 and how does it affect signal integrity?
The SMF51A-M3-18 exhibits 151 pF typical junction capacitance at 0 V bias and 1 MHz, per the Vishay datasheet. This capacitance appears in parallel with the protected line and forms a low-pass filter with source impedance - limiting usable bandwidth. At 100 Ω source impedance, the −3 dB point is ~10.5 MHz, making SMF51A-M3-18 appropriate for LIN (20 kbps), RS-485 (10 Mbps), and CAN FD (2 Mbps) but unsuitable for USB 2.0 (480 Mbps) or MIPI D-PHY.
SMF51A-M3-18 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):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 82.4V
- Current - Peak Pulse (10/1000µs):
- 2.4A
- Power - Peak Pulse:
- 200W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 151pF @ 1MHz
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AB (SMF)
SMF51A-M3-18 FAQ
1.How can I place an order for SMF51A-M3-18 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF51A-M3-18 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 SMF51A-M3-18 reliable?
The price and inventory of SMF51A-M3-18 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF51A-M3-18 is usually 5 days.
3.What payment methods are accepted for SMF51A-M3-18?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF51A-M3-18 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF51A-M3-18?
SMF51A-M3-18 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF51A-M3-18 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 SMF51A-M3-18?
For technical support, including SMF51A-M3-18 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF51A-M3-18 requirements.
6.How does Aetrix verify that SMF51A-M3-18 is sourced from the original manufacturer or authorized distributors?
All SMF51A-M3-18 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 SMF51A-M3-18 meets industry standards.
7.What is the process for return or replacement of SMF51A-M3-18?
All SMF51A-M3-18 units undergo pre-shipment inspection (PSI). If there is an issue with SMF51A-M3-18, 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 SMF51A-M3-18 part is unused and in its original packaging.
Return procedure for SMF51A-M3-18:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF51A-M3-18 Tags
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