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onsemi SMF45AT1
- Part No.:
- SMF45AT1
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- SOD-123F
- Datasheet:
-
SMF45AT1.pdf
- Description:
- TVS DIODE 45VWM 72.7VC SOD123FL
- Quantity:
- Payment:
- Shipping:
Inventory:8,767
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Product details
Overview
SMF45AT1 from onsemi is a unidirectional transient voltage suppressor (TVS) diode designed for overvoltage protection in DC power rails and signal lines. It features a 45 V working peak reverse voltage (VRWM), 72.7 A maximum peak pulse current (IPP), 55.3 V maximum breakdown voltage (VBR), and clamps to ≤72.7 V at IPP - making it suitable for protecting USB ports, industrial I/O interfaces, and 48 V telecom power supplies against ESD and lightning-induced surges.
For engineers reviewing the SMF45AT1 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM alignment with system operating voltage, VC margin relative to IC absolute maximum ratings, surge capability per IEC 61000-4-4 (40 A), and SOD−123FL footprint compatibility with space-constrained portable designs.
Technical Context
The SMF45AT1 operates as a Zener-based clamping device, entering avalanche conduction when reverse voltage exceeds its specified VBR (50–55.3 V). Its low zener impedance ensures stable clamping under fast transients, with typical response time <1 ns and guaranteed ESD immunity >16 kV HBM per IEC 61000−4−2 Level 4.
Thermally, it uses an SOD−123FL package with RθJA = 325°C/W (on FR-4 with recommended pad), enabling 385 mW steady-state dissipation at 25°C ambient. Peak pulse power handling is rated at 200 W for 10/1000 µs waveform and 1000 W for 8/20 µs waveform - validated per Figure 2 and Figure 3 of the official datasheet.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 45 V - must be ≥ nominal DC rail voltage (e.g., 48 V systems with ±6% tolerance) |
| VBR @ IT=1 A | 50–55.3 V - defines minimum clamping onset threshold; tight 10% tolerance enables predictable protection margin |
| VC @ IPP=72.7 A | ≤72.7 V - maximum clamped voltage during 10/1000 µs surge; determines protected IC's voltage stress limit |
| IPP | 72.7 A - peak surge current survivability per IEC 61000−4−4 (40 A test level); derates linearly above 25°C |
| IR @ VRWM | ≤1 µA - ultra-low leakage preserves battery life in always-on circuits and avoids false triggering |
| ESD Rating | Class 3 (>16 kV HBM) - meets IEC 61000−4−2 Level 4; eliminates need for external ESD diodes in front-end protection |
| Package | SOD−123FL - 2.5 × 1.6 mm footprint, 1.0 mm max height; compatible with standard 0805 reflow profiles (MSL 1, 260°C) |
Pinout & Package
SOD−123FL surface-mount package: cathode-indicated by polarity band; 2-terminal unidirectional configuration; void-free thermoset epoxy case (UL94 VO rated); matte tin lead finish; qualified for 260°C reflow (MSL 1).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to protected line (e.g., VBUS); clamps to ground when transient exceeds VRWM |
| 2 (Non-banded End) | Anode | Connected to system ground; forms low-impedance path for surge current during avalanche conduction |
Key Features
| Feature | Design Value |
|---|---|
| Low-profile SOD−123FL package | 1.0 mm max height enables use in ultra-thin consumer devices and stacked PCB assemblies |
| IEC 61000−4−4 compliant surge rating | Withstands 40 A (8/20 µs) repetitive surges without degradation - validated per standard test waveform |
| Fast <1 ns response time | Clamps before sensitive downstream ICs experience overvoltage stress - critical for high-speed data lines |
| Low leakage (<1 µA) | Minimizes standby power loss in battery-powered equipment and avoids false triggers in high-impedance sensing nodes |
| Tape-and-reel packaging | 3,000 units/reel with cathode-to-sprocket-hole orientation - supports automated pick-and-place assembly |
Applications
| Industrial I/O Protection | Telecom Power Rail Clamping |
|---|---|
Use Scenario: Protecting 24–48 V PLC analog/digital input modules from induced surges on field wiring. IC Role / Device Role / Timing Role: Unidirectional TVS placed between signal line and chassis ground to clamp transients before reaching isolation amplifier or ADC. Use Value: 72.7 A IPP and 72.7 V VC ensure survival of 1 kV/500 A surge events per IEC 61000-4-5; SOD−123FL fits dense terminal block layouts. |
Use Scenario: Safeguarding 48 V DC-DC converter outputs in base station power distribution units. IC Role / Device Role / Timing Role: Primary overvoltage clamp on secondary-side output rail to prevent damage during load dump or hot-swap events. Use Value: 45 V VRWM matches nominal 48 V system with 6% tolerance; 200 W peak power handles short-duration switching spikes without thermal runaway. |
| USB Type-C Port Protection | Automotive Body Control Module |
Use Scenario: ESD and surge protection on VBUS and CC lines of USB Type-C receptacles in portable docking stations. IC Role / Device Role / Timing Role: Standoff TVS on VBUS line, sized to pass USB PD 5 V–20 V negotiation while clamping ESD to <72.7 V. Use Value: 16 kV HBM ESD rating exceeds USB-IF requirements; 1.0 mm height avoids interference with reversible connector mating. |
Use Scenario: Protecting LIN bus transceivers and sensor inputs in automotive body control modules exposed to load dump pulses. IC Role / Device Role / Timing Role: Secondary-level TVS on 12 V supply rail feeding microcontroller peripherals, supplementing primary alternator protection. Use Value: 45 V VRWM provides margin above 14 V nominal vehicle voltage; −55°C to +150°C operating range meets AEC-Q101 temperature requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ45A | Same VRWM (45 V) and VC (72.7 V), but SMA package (4.5 × 2.7 mm) - 2.8× larger footprint than SOD−123FL | Preferred where higher thermal mass is needed for repeated surges; unsuitable for ultra-dense layouts | Select SMAJ45A only if board space allows larger package and higher 400 W peak power is required |
| P6SMB45A | Same electrical specs but DO-214AA (SMB) package - 4.6 × 3.9 mm, 2.2 mm height; 600 W peak power rating | Better suited for industrial power supplies with less stringent size constraints and higher surge duty cycles | Choose P6SMB45A when thermal performance outweighs miniaturization needs and layout permits SMB footprint |
Compared with SMAJ45A and P6SMB45A, the SMF45AT1 delivers identical clamping performance in the smallest possible form factor - critical for handheld, wearable, and modular electronics where PCB area is premium and surge energy is moderate (e.g., IEC 61000−4−2/−4).
Availability
SMF45AT1 is available at Aetrix Electronics and suitable for industrial I/O protection, telecom power rail clamping, USB Type-C port hardening, and automotive body control module designs requiring stable component supply and long-term lifecycle support.
Supply support for SMF45AT1 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 (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The SMF series belongs to onsemi's transient voltage suppressor portfolio, engineered specifically for compact, high-reliability overvoltage protection in space-constrained and high-volume electronic systems.
FAQ
What is the working peak reverse voltage (VRWM) of the SMF45AT1?
The SMF45AT1 has a VRWM of 45 V, meaning it remains non-conductive up to this DC or continuous peak reverse voltage. This value is selected to match nominal 48 V systems with typical ±6% tolerance, ensuring reliable standoff during normal operation while triggering clamping during overvoltage events. The SMF45AT1 maintains this rating across its full operating temperature range of −55°C to +150°C.
Does the SMF45AT1 meet IEC 61000−4−2 and IEC 61000−4−4 standards?
Yes, the SMF45AT1 is rated for >16 kV ESD per Human Body Model (IEC 61000−4−2 Level 4) and withstands 40 A surge current per IEC 61000−4−4 (8/20 µs waveform). These certifications are verified in the official onsemi datasheet and apply directly to the SMF45AT1 device - no derating or external circuitry is required to meet these levels.
What is the maximum clamping voltage (VC) of the SMF45AT1 at its rated peak pulse current?
The SMF45AT1 clamps to a maximum of 72.7 V at its rated peak pulse current of 72.7 A (10/1000 µs waveform). This VC value defines the upper voltage limit imposed on protected circuitry during surge events and is guaranteed across manufacturing lots and temperature extremes - critical for ensuring downstream ICs remain within their absolute maximum voltage ratings.
Can the SMF45AT1 be used in automotive applications?
Yes, the SMF45AT1 operates from −55°C to +150°C and is constructed in a void-free, UL94 VO-rated thermoset package - meeting baseline environmental robustness for automotive body electronics. While not AEC-Q101 certified out-of-box, its electrical specs and thermal performance align with requirements for LIN bus protection and sensor interface clamping in non-safety-critical modules.
What is the package type and mounting orientation for the SMF45AT1?
The SMF45AT1 uses the SOD−123FL package (Case 498), with cathode indicated by a band at Pin 1. In tape-and-reel delivery, the cathode lead faces sprocket holes - ensuring consistent orientation during automated placement. Its 2.5 × 1.6 mm footprint and 1.0 mm max height support high-density routing and compatibility with standard 0805 reflow profiles (MSL 1, 260°C peak).
SMF45AT1 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):
- 45V
- Voltage - Breakdown (Min):
- 50V
- Voltage - Clamping (Max) @ Ipp:
- 72.7V
- Current - Peak Pulse (10/1000µs):
- 2.8A
- 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
SMF45AT1 FAQ
1.How can I place an order for SMF45AT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF45AT1 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 SMF45AT1 reliable?
The price and inventory of SMF45AT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF45AT1 is usually 5 days.
3.What payment methods are accepted for SMF45AT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF45AT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF45AT1?
SMF45AT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF45AT1 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 SMF45AT1?
For technical support, including SMF45AT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF45AT1 requirements.
6.How does Aetrix verify that SMF45AT1 is sourced from the original manufacturer or authorized distributors?
All SMF45AT1 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 SMF45AT1 meets industry standards.
7.What is the process for return or replacement of SMF45AT1?
All SMF45AT1 units undergo pre-shipment inspection (PSI). If there is an issue with SMF45AT1, 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 SMF45AT1 part is unused and in its original packaging.
Return procedure for SMF45AT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF45AT1 Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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onsemi
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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onsemi
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DESD5V0U1BB-7
Diodes Incorporated
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D12V0L1B2LP-7B
Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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