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onsemi SMF12AT3G
- Part No.:
- SMF12AT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- SOD-123F
- Datasheet:
-
SMF12AT3G.pdf
- Description:
- TVS DIODE 12VWM 19.9VC SOD123FL
- Quantity:
- Payment:
- Shipping:
Inventory:4,098
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Product details
Overview
SMF12AT3G from onsemi is a unidirectional Zener transient voltage suppressor (TVS) diode designed for primary overvoltage protection of DC power rails and signal lines. It features a 12 V working peak reverse voltage (VRWM), 14.0 V typical breakdown voltage (VBR) at 1 mA, 19.9 V maximum clamping voltage (VC) at 10.1 A peak pulse current (IPP), and 200 W peak pulse power rating at 10/1000 µs waveform - ideal for safeguarding USB ports, I/O interfaces, and low-voltage power inputs in portable electronics.
For engineers reviewing the SMF12AT3G datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system operating voltage, VC margin relative to IC absolute maximum ratings, surge current handling under IEC 61000-4-4 (40 A), ESD robustness per IEC 61000-4-2 Level 4 (>16 kV HBM), and SOD-123FL footprint compatibility with space-constrained PCB layouts.
Technical Context
The SMF12AT3G operates as a voltage-clamping device that remains high-impedance below VRWM (12 V) and rapidly avalanches into low-impedance conduction when transient voltage exceeds VBR (13.3–14.7 V). Its Zener-based structure delivers sub-nanosecond response time (<1 ns) and low dynamic impedance, enabling effective suppression of fast-rising ESD and EFT events without affecting normal circuit operation.
It is rated for 200 W peak pulse power (10/1000 µs), 1000 W peak power (8/20 µs), and supports continuous operation from –55 °C to +150 °C. The device meets IEC 61000-4-2 Level 4 (±16 kV contact, ±25 kV air) and IEC 61000-4-4 (±40 A, 5/50 ns) immunity standards, with cathode-anode polarity clearly marked via band on SOD-123FL package.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 12 V - Maximum continuous reverse voltage before clamping begins; must be ≥ nominal rail voltage (e.g., 12 V supply) to avoid leakage during normal operation. |
| VBR (min/typ/max) | 13.3 / 14.0 / 14.7 V @ 1 mA - Ensures reliable turn-on above system operating voltage while maintaining margin against tolerance drift. |
| VC (max) @ IPP | 19.9 V @ 10.1 A - Clamped voltage seen by protected IC during worst-case 10/1000 µs surge; determines if downstream components remain within safe operating area. |
| IPP (max) | 10.1 A - Peak surge current the device can safely divert without degradation; correlates directly with IEC 61000-4-4 40 A test compliance. |
| Leakage (IR) | 2.5 µA @ 12 V - Ultra-low reverse leakage preserves battery life and avoids loading in always-on circuits like real-time clocks or sensor bias rails. |
| Response time | <1 ns - Fast enough to clamp ESD transients before they propagate past board-level filtering or reach sensitive CMOS inputs. |
| ESD rating | >16 kV HBM - Meets IEC 61000-4-2 Level 4, qualifying for front-panel buttons, USB connectors, and other user-accessible interfaces. |
Pinout & Package
SOD-123FL surface-mount package: 1.0 mm max height, 2.7 mm × 1.6 mm footprint (8.45 mm²), Pb-free matte tin lead finish, MSL 1 rated, compatible with standard reflow profiles up to 260 °C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded end) | Cathode | Connected to protected line (e.g., VBUS, data line); clamping occurs when voltage at this terminal exceeds VBR relative to anode. |
| 2 (Non-banded end) | Anode | Typically tied to ground or lower-potential reference; establishes reference for clamping action and defines unidirectional conduction path. |
Key Features
| Feature | Design Value |
|---|---|
| Low-profile SOD-123FL package | 1.0 mm max height enables use in ultra-thin consumer devices (e.g., smartphones, wearables) without interfering with mechanical stack-up. |
| 200 W peak pulse power (10/1000 µs) | Supports robust protection against lightning-induced surges and industrial switching transients in 12 V systems without derating. |
| IEC 61000-4-4 compliant (40 A) | Validated for immunity testing in industrial control and automotive body electronics where repetitive fast transients occur on power and signal lines. |
| ESD robustness >16 kV HBM | Eliminates need for secondary ESD protection on exposed ports, reducing BOM count and layout complexity in USB 2.0, UART, and GPIO interfaces. |
| Pb-free and RoHS-compliant | Meets global environmental regulations and qualifies for lead-free assembly processes without compromising thermal or electrical performance. |
Applications
| USB 2.0 Data Line Protection | 12 V Automotive Power Input |
|---|---|
Use Scenario: Protecting D+ and D− lines of USB 2.0 peripherals from ESD events during hot-plug insertion and cable handling. IC Role / Device Role / Timing Role: Unidirectional TVS placed between each data line and ground to clamp transients while preserving signal integrity and DC bias. Use Value: Maintains <1 pF capacitance (per datasheet Fig. 8 at 50% VRWM), ensuring minimal signal distortion and full-speed USB 2.0 compliance (480 Mbps). |
Use Scenario: Safeguarding 12 V power input of infotainment modules, telematics units, or ADAS sensors against load-dump and jump-start transients. IC Role / Device Role / Timing Role: Primary clamping device across input rail and chassis ground, absorbing energy before it reaches downstream DC/DC converters or microcontrollers. Use Value: Withstands 200 W peak power and 10.1 A surge current, meeting ISO 7637-2 Pulse 1 (–150 V, 2 Ω source) and Pulse 2a (25 V, 10 mΩ) requirements. |
| Industrial Sensor Signal Conditioning | Portable Medical Device Battery Rail |
Use Scenario: Shielding analog sensor outputs (e.g., 4–20 mA loop, thermocouple amplifiers) from EFT bursts in factory automation environments. IC Role / Device Role / Timing Role: Low-leakage (2.5 µA) TVS connected between signal line and local AGND to prevent false triggering or ADC offset shifts during EMC testing. Use Value: Sub-1 ns response ensures clamping occurs before transient couples into op-amp feedback networks, preserving measurement accuracy and stability. |
Use Scenario: Protecting lithium-ion battery monitoring ICs and fuel gauges in handheld diagnostic tools from accidental ESD discharge during field use. IC Role / Device Role / Timing Role: Standoff-rated (12 V) TVS on battery input to block transients while allowing full 3.0–4.2 V cell voltage range to pass unattenuated. Use Value: 12 V VRWM aligns precisely with common 3S Li-ion packs (nominal 11.1 V), avoiding unnecessary conduction during normal charge/discharge cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12A | Same VRWM (12 V), but SMA package (larger footprint, 2.5 mm × 4.5 mm); 400 W peak power rating; higher thermal mass. | Better suited for higher-energy surges in industrial power supplies; less suitable for space-constrained mobile designs. | Select SMAJ12A only when PCB area allows larger package and surge energy exceeds 200 W capability of SMF12AT3G. |
| 1.5SMC12A | Same VRWM (12 V), but SMC package (7.1 mm × 6.2 mm); 1500 W peak power; significantly higher clamping voltage (20.1 V). | Used in AC mains-connected equipment or high-power DC systems where physical size is not constrained and higher VC is acceptable. | Choose 1.5SMC12A for legacy industrial designs requiring higher surge margin, but verify downstream ICs tolerate 20.1 V clamping. |
Compared with SMAJ12A and 1.5SMC12A, the SMF12AT3G offers optimal balance of compact SOD-123FL footprint, 200 W surge handling, and low 19.9 V clamping - making it the preferred choice for modern portable, automotive, and IoT edge devices where board space and voltage margin are critical.
Availability
SMF12AT3G is available at Aetrix Electronics and suitable for USB interface protection, 12 V automotive power conditioning, and industrial sensor signal line safeguarding requiring stable component supply and long-term lifecycle support.
Supply support for SMF12AT3G 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
onsemi (Nasdaq: ON) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The SMF12AT3G belongs to onsemi's SMF5.0AT1 Series of unidirectional TVS diodes, engineered specifically for high-reliability, low-footprint overvoltage protection in battery-powered and space-sensitive electronic systems.
FAQ
What is the working peak reverse voltage (VRWM) of the SMF12AT3G?
The SMF12AT3G has a VRWM of 12 V, meaning it remains non-conductive under steady-state reverse voltages up to this level. This value is selected to match nominal 12 V supply rails while providing sufficient margin above typical operating voltage to prevent leakage during normal use. The SMF12AT3G datasheet confirms VRWM = 12 V at TA = 25°C.
Does the SMF12AT3G meet IEC 61000-4-2 and IEC 61000-4-4 immunity standards?
Yes, the SMF12AT3G is rated for >16 kV contact discharge per IEC 61000-4-2 Level 4 (HBM) and withstands 40 A surge current per IEC 61000-4-4 (5/50 ns waveform). These ratings are validated in the official onsemi SMF5.0AT1 Series datasheet (Rev. 2, May 2007), confirming its suitability for front-end ESD/EFT protection in commercial and industrial equipment using SMF12AT3G.
What is the maximum clamping voltage (VC) of the SMF12AT3G at its rated peak pulse current?
The SMF12AT3G exhibits a maximum clamping voltage (VC) of 19.9 V when subjected to its rated peak pulse current (IPP) of 10.1 A under the 10/1000 µs waveform. This VC value defines the highest voltage imposed on protected circuitry during a surge event and is critical for ensuring downstream ICs remain within their absolute maximum ratings - a key parameter specified for SMF12AT3G in Table 3 of the onsemi datasheet.
Is the SMF12AT3G packaged in a lead-free format?
Yes, the "G" suffix in SMF12AT3G explicitly denotes a Pb-free, RoHS-compliant package. The device uses 100% matte tin lead finish, meets UL 94 V-0 flammability rating, and is qualified for reflow soldering up to 260 °C. This Pb-free construction is documented in the ordering information and mechanical specifications sections of the SMF5.0AT1 Series datasheet applicable to SMF12AT3G.
What is the thermal resistance junction-to-ambient (RJA) for the SMF12AT3G in standard mounting conditions?
The SMF12AT3G has a thermal resistance junction-to-ambient (RJA) of 325 °C/W when mounted on FR-4 PCB with recommended minimum pad size, as stated in the "Maximum Ratings" table of the onsemi SMF5.0AT1 Series datasheet. This value reflects its ability to dissipate heat during transient events and informs derating calculations for repeated surge exposure - a verified specification for SMF12AT3G under defined test conditions.
SMF12AT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- SOD-123F
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-123FL
SMF12AT3G FAQ
1.How can I place an order for SMF12AT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF12AT3G 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 SMF12AT3G reliable?
The price and inventory of SMF12AT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF12AT3G is usually 5 days.
3.What payment methods are accepted for SMF12AT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF12AT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF12AT3G?
SMF12AT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF12AT3G 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 SMF12AT3G?
For technical support, including SMF12AT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF12AT3G requirements.
6.How does Aetrix verify that SMF12AT3G is sourced from the original manufacturer or authorized distributors?
All SMF12AT3G 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 SMF12AT3G meets industry standards.
7.What is the process for return or replacement of SMF12AT3G?
All SMF12AT3G units undergo pre-shipment inspection (PSI). If there is an issue with SMF12AT3G, 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 SMF12AT3G part is unused and in its original packaging.
Return procedure for SMF12AT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF12AT3G Tags
-
ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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ESD5Z3.3T1G
onsemi
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D5V0H1B2LP-7B
Diodes Incorporated
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D5V0P1B2LP-7B
Diodes Incorporated
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DESD5V0U1BA-7
Diodes Incorporated
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ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
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DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
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D5V0L1B2WS-7
Diodes Incorporated
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