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Vishay SMF24A-HE3_A18
- Part No.:
- SMF24A-HE3_A18
- Manufacturer:
- Vishay
- Category:
- TVS Diodes
- Package:
- DO-219AB
- Datasheet:
-
SMF24A-HE3_A18.pdf
- Description:
- ESD PROTECTION DIODE SMF DO219AB
- Quantity:
- Payment:
- Shipping:
Inventory:3,255
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Product details
Overview
SMF24A-HE3_A18 from Vishay Semiconductors is a unidirectional surface-mount ESD protection diode in the SMF (DO-219AB) package, designed for clamping transient overvoltages on data and power lines. It features a 24 V stand-off voltage (VRWM), 26.7–29.6 V reverse breakdown (VBR), 5.1 A peak pulse current (IPPM), 38.9 V maximum clamping voltage (VC) at IPPM, and 244 pF typical capacitance at 0 V/1 MHz - optimized for high-speed USB 2.0, HDMI, and industrial I/O protection.
For engineers reviewing the SMF24A-HE3_A18 datasheet, SMF24A-HE3_A18 pinout, SMF24A-HE3_A18 application, or SMF24A-HE3_A18 equivalent, this device delivers verified ±30 kV IEC 61000-4-2 ESD immunity, AEC-Q101 qualification, low 1.08 mm profile, and SOD-123W-compatible footprint - critical for space-constrained automotive and industrial PCB layouts.
Technical Context
This unidirectional TVS diode operates as a shunt-type transient suppressor, conducting only when reverse voltage exceeds its breakdown threshold to divert surge energy away from sensitive downstream circuitry. Its low incremental surge resistance and "Low Noise" fast-response technology ensure sub-nanosecond turn-on during ESD events.
The SMF24A-HE3_A18 is rated for 200 W peak pulse power (10/1000 μs), 1000 W (8/20 μs), and supports 50 A non-repetitive forward surge current (8.3 ms half-sine). It maintains operation across -65 °C to +175 °C and achieves thermal resistance of 180 K/W on standard epoxy-glass PCBs with 3 mm × 3 mm Cu pads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRWM) | 24 V - maximum continuous reverse operating voltage before clamping begins; defines safe signal swing margin for 24 V nominal bus lines. |
| Reverse Breakdown (VBR) | 26.7–29.6 V at 1 mA - guaranteed conduction onset range; ensures reliable triggering above system operating voltage. |
| Clamping Voltage (VC) | 38.9 V max at 5.1 A (10/1000 μs) - limits transient voltage seen by protected ICs; enables robust interface survivability under surge stress. |
| Capacitance (CD) | 244 pF typical at 0 V, 1 MHz - low enough for USB 2.0 (480 Mbps) signal integrity; higher than RF-grade suppressors but suitable for medium-speed digital lines. |
| ESD Immunity | ±30 kV contact & air discharge per IEC 61000-4-2 - exceeds Level 4 immunity requirements for industrial and automotive end-equipment. |
| AEC-Q101 Qualified | Yes - validated for automotive-grade reliability including HBM >8 kV, enabling use in under-hood and infotainment modules. |
| Package | DO-219AB (SMF) - 3.9 × 1.9 × 1.08 mm low-profile SMD outline compatible with SOD-123W footprint and reflow/wave soldering. |
Pinout & Package
SMF24A-HE3_A18 uses the DO-219AB (SMF) package: a two-terminal, cathode-marked surface-mount device with a molded plastic body, 1.08 mm max height, and 3.9 mm × 1.9 mm footprint. The cathode bar identifies the anode-to-cathode polarity for correct orientation in series-shunt protection configurations.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Transient current entry point during positive surges | Connected to protected line; conducts surge current toward ground when cathode is held at reference potential. |
| Cathode (bar-marked end) | Clamping reference terminal | Typically tied to system ground or low-impedance return path; establishes clamping voltage relative to this node. |
Key Features
| Feature | Design Value |
|---|---|
| 200 W peak pulse power (10/1000 μs) | Enables suppression of moderate-energy transients without degradation in compact industrial sensor interfaces. |
| ±30 kV IEC 61000-4-2 ESD immunity | Eliminates need for secondary board-level ESD mitigation in handheld test equipment and factory automation terminals. |
| Low 1.08 mm profile | Supports ultra-thin designs in automotive camera modules and portable diagnostic tools where Z-height is constrained. |
| AEC-Q101 qualified | Validated for automotive temperature cycling, mechanical shock, and humidity testing - reduces qualification burden for Tier 1 suppliers. |
| SOD-123W footprint compatibility | Allows drop-in replacement or layout reuse with existing SOD-123W land patterns, minimizing PCB redesign effort. |
Applications
| Industrial Sensor Interface | Automotive Body Control Module |
|---|---|
Use Scenario: Protecting 24 V analog input channels (e.g., 4–20 mA current loop receivers) from field-induced surges in factory PLC I/O cards. IC Role / Device Role / Timing Role: Shunt clamping diode placed between signal line and ground, activated within <1 ns upon overvoltage detection. Use Value: Limits transient voltage to ≤38.9 V, preventing damage to precision op-amps and ADC front-ends while maintaining 244 pF loading compatible with <100 kHz bandwidth signals. |
Use Scenario: Safeguarding LIN bus transceiver pins against load-dump and ESD events in door module control units. IC Role / Device Role / Timing Role: Unidirectional TVS connected between LIN data line and chassis ground, providing primary ESD hardening per ISO 10605. Use Value: Delivers ±30 kV contact discharge immunity and AEC-Q101 qualification, meeting OEM requirements without additional external filtering components. |
| USB 2.0 Port Protection | Smart Building HVAC Controller |
Use Scenario: Clamping ESD on D+ and D- lines of embedded USB host ports in industrial HMIs and medical devices. IC Role / Device Role / Timing Role: Low-capacitance TVS placed directly at connector, acting as first-line defense before USB PHY IC. Use Value: 244 pF capacitance preserves signal integrity up to 480 Mbps; 38.9 V clamping prevents PHY latch-up during ±8 kV contact discharge events. |
Use Scenario: Protecting RS-485 communication lines (24 V powered) in distributed HVAC controllers exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Bidirectional protection implemented using two SMF24A-HE3_A18 diodes in back-to-back configuration across differential pair. Use Value: Achieves 200 W pulse handling per line and 175 °C junction rating for reliable operation in hot attic-mounted enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ESD protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SP1003-02UTG | 24 V VRWM, 33 V VC @ 5.1 A, 120 pF - lower capacitance but 13% higher clamping voltage. | Better suited for high-speed USB 3.0 (5 Gbps) due to lower CD; less effective for 24 V rail clamping headroom. | Choose SP1003-02UTG when signal bandwidth >1 GHz dominates over clamping voltage margin. |
| ON Semiconductor SZ1.5SMC24A | 24 V VRWM, 38.9 V VC @ 43.5 A, 1500 pF - same clamping but 6× higher capacitance and SMA package (4.5 mm height). | Designed for higher-energy surges (1500 W); unsuitable for space-constrained or high-frequency interfaces. | Choose SZ1.5SMC24A only for legacy 24 V power rail protection where PCB height and speed are not limiting. |
Compared with SP1003-02UTG and SZ1.5SMC24A, SMF24A-HE3_A18 uniquely balances 244 pF capacitance, 38.9 V clamping, and 1.08 mm height - making it optimal for next-generation industrial USB and 24 V sensor nodes where size, speed, and voltage margin must coexist.
Availability
SMF24A-HE3_A18 is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body electronics, USB 2.0 port protection, and smart building HVAC controllers requiring stable component supply and long-term lifecycle support.
Supply support for SMF24A-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 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 targets compact, high-performance ESD protection for space-constrained and thermally demanding applications - emphasizing AEC-Q101 qualification, low-profile packaging, and precise clamping performance across wide temperature ranges.
FAQ
What is the maximum clamping voltage of SMF24A-HE3_A18 under standard surge conditions?
The SMF24A-HE3_A18 has a maximum reverse clamping voltage (VC) of 38.9 V when subjected to a 10/1000 μs waveform at its rated peak pulse current of 5.1 A. This value is specified in the Vishay datasheet (Document Number: 85881, Rev. 2.4) and ensures downstream ICs see limited overvoltage during transient events. The clamping behavior is consistent across its full operating temperature range of -65 °C to +175 °C.
Is SMF24A-HE3_A18 qualified for automotive applications?
Yes, SMF24A-HE3_A18 is AEC-Q101 qualified and rated for human body model (HBM) ESD >8 kV. It meets automotive reliability requirements including temperature cycling, mechanical shock, and humidity testing. Its -65 °C to +175 °C operating range and DO-219AB package make it suitable for under-hood and cabin modules. The "HE3_A18" suffix confirms AEC-Q101 and RoHS-compliant lead-free termination.
What is the capacitance of SMF24A-HE3_A18 and how does it affect signal integrity?
SMF24A-HE3_A18 exhibits 244 pF typical capacitance at 0 V and 1 MHz. This value is measured per the Vishay datasheet and impacts high-speed digital lines: it is well-suited for USB 2.0 (480 Mbps) and RS-485, but may limit rise/fall times in >1 GHz applications. For such cases, lower-capacitance alternatives like SP1003-02UTG (120 pF) should be evaluated - though with trade-offs in clamping voltage and package height.
Can SMF24A-HE3_A18 be used for bidirectional protection?
SMF24A-HE3_A18 is a unidirectional TVS diode and cannot provide symmetrical clamping for AC or differential signals alone. However, it can be configured in a back-to-back arrangement (two devices anode-to-anode) to achieve bidirectional protection - commonly applied on RS-485 or CAN lines. In that topology, each SMF24A-HE3_A18 handles one polarity, preserving its 38.9 V clamping and 244 pF characteristics per leg.
What is the package type and soldering compatibility of SMF24A-HE3_A18?
SMF24A-HE3_A18 uses the DO-219AB (SMF) package: 3.9 mm × 1.9 mm × 1.08 mm, with cathode bar marking. It is fully compatible with standard reflow soldering profiles (peak temperature ≤260 °C) and wave soldering. Its footprint aligns with SOD-123W, enabling layout reuse. Moisture sensitivity level is MSL 1 (unlimited floor life), eliminating bake requirements prior to assembly.
SMF24A-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):
- 24V
- Voltage - Breakdown (Min):
- 26.7V
- Voltage - Clamping (Max) @ Ipp:
- 38.9V
- Current - Peak Pulse (10/1000µs):
- 5.1A
- Power - Peak Pulse:
- 200W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- 244pF @ 1MHz
- Operating Temperature:
- -65°C ~ 175°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AB (SMF)
SMF24A-HE3_A18 FAQ
1.How can I place an order for SMF24A-HE3_A18 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF24A-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 SMF24A-HE3_A18 reliable?
The price and inventory of SMF24A-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 SMF24A-HE3_A18 is usually 5 days.
3.What payment methods are accepted for SMF24A-HE3_A18?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF24A-HE3_A18 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF24A-HE3_A18?
SMF24A-HE3_A18 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF24A-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 SMF24A-HE3_A18?
For technical support, including SMF24A-HE3_A18 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF24A-HE3_A18 requirements.
6.How does Aetrix verify that SMF24A-HE3_A18 is sourced from the original manufacturer or authorized distributors?
All SMF24A-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 SMF24A-HE3_A18 meets industry standards.
7.What is the process for return or replacement of SMF24A-HE3_A18?
All SMF24A-HE3_A18 units undergo pre-shipment inspection (PSI). If there is an issue with SMF24A-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 SMF24A-HE3_A18 part is unused and in its original packaging.
Return procedure for SMF24A-HE3_A18:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF24A-HE3_A18 Tags
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