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onsemi SMF40AT1G
- Part No.:
- SMF40AT1G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- SOD-123F
- Datasheet:
-
SMF40AT1G.pdf
- Description:
- TVS DIODE 40VWM 64.5VC SOD123FL
- Quantity:
- Payment:
- Shipping:
Inventory:8,387
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Product details
Overview
SMF40AT1G from onsemi is a unidirectional Zener transient voltage suppressor (TVS) diode in SOD-123FL package, designed to protect sensitive electronics against ESD and surge transients. It features a 40 V working peak reverse voltage (VRWM), 49.1 V maximum clamping voltage (VC) at 64.5 A peak pulse current (IPP), and <1 ns response time - ideal for input/output line protection in power supplies and portable devices.
For engineers reviewing the SMF40AT1G datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system operating voltage, VC margin relative to IC absolute maximum ratings, IEC61000-4-2/4-4 compliance, and SOD-123FL board space constraints in high-density layouts.
Technical Context
The SMF40AT1G operates as a unidirectional avalanche breakdown device, triggered when reverse voltage exceeds its 44.4–49.1 V breakdown range (VBR). Its low zener impedance and fast sub-nanosecond response enable effective suppression of 8/20 µs surges up to 1000 W (non-repetitive) and 200 W (10/1000 µs).
It meets IEC61000-4-2 Level 4 (±16 kV contact, ±15 kV air) and IEC61000-4-4 (40 A, 5/50 ns) standards. Thermal resistance is 325 °C/W (junction-to-ambient, FR-4 PCB), with MSL 1 reflow rating and Pb-free matte tin lead finish.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 40 V - Maximum continuous reverse operating voltage before clamping begins; must be ≥ circuit's DC or peak AC rail voltage. |
| VBR @ IT=1 A | 44.4–49.1 V - Breakdown occurs within this range at 1 mA test current; defines turn-on threshold consistency. |
| VC @ IPP=64.5 A | ≤64.5 V - Clamped voltage during 10/1000 µs surge; determines maximum stress imposed on downstream ICs. |
| IPP (10/1000 µs) | 64.5 A - Peak surge current the device safely clamps without failure; correlates directly to energy handling (200 W). |
| Response Time | <1 ns - Enables protection of high-speed interfaces (e.g., USB, HDMI) before transient energy reaches protected ICs. |
| ESD Rating | Class 3 HBM (>16 kV) - Validated for robustness against human-body model discharges in handheld and benchtop equipment. |
| Package | SOD-123FL - Surface-mount, low-profile (1.0 mm max height), 8.45 mm² footprint; compatible with standard pick-and-place and reflow processes. |
Pinout & Package
SOD-123FL is a two-terminal surface-mount plastic package with cathode indicated by a polarity band. Mounting position is unrestricted; qualified for 260°C reflow (MSL 1). Lead finish is 100% matte tin; epoxy meets UL 94 V-0.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to protected line's higher-potential side (e.g., VBUS, signal high); clamping occurs when voltage exceeds VRWM. |
| 2 (Non-banded End) | Anode | Connected to ground or lower-potential reference; completes conduction path during transient events. |
Key Features
| Feature | Design Value |
|---|---|
| IEC61000-4-4 Compliance | Rated for 40 A surge (5/50 ns), enabling use in industrial control inputs exposed to switching noise and inductive kickback. |
| Low Clamping Ratio (VC/VBR) | ~1.45 - Tight ratio ensures minimal overvoltage overshoot during clamping, critical for protecting 3.3 V or 5 V logic rails. |
| Pb-Free & RoHS Compliant | SMF40AT1G suffix confirms matte Sn lead finish and exemption from lead-based solder requirements per EU RoHS Directive. |
| Small Footprint & Low Profile | 8.45 mm² area and ≤1.0 mm height allow placement near connectors or IC pins in space-constrained mobile and IoT designs. |
| Tape & Reel Packaging | 3000 units/reel (8 mm tape) supports automated SMT assembly with cathode oriented toward sprocket holes for consistent placement. |
Applications
| USB Power Input Protection | DC Power Supply Rail Protection |
|---|---|
|
Use Scenario: Protecting USB Type-C VBUS lines (5 V nominal) from hot-plug transients and ESD events during cable insertion. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VBUS and GND, clamping surges before they reach USB controller or PMIC. Use Value: Prevents latch-up or damage to 5 V tolerant USB PHYs by limiting VBUS to ≤64.5 V during 64.5 A surges, while occupying minimal PCB area. |
Use Scenario: Safeguarding 48 V telecom power supply outputs against lightning-induced surges and load-dump transients. IC Role / Device Role / Timing Role: Secondary-level TVS on regulated output rail, coordinated with upstream MOVs and fuses for multi-stage protection. Use Value: Withstands 200 W (10/1000 µs) surges and maintains VRWM ≥40 V, ensuring compatibility with 48 V systems where derating allows 40 V minimum standoff. |
| Industrial Sensor Interface Protection | Automotive Body Control Module Inputs |
|
Use Scenario: Shielding analog sensor inputs (e.g., 0–10 V pressure transducers) from ESD and cable discharge events in factory automation. IC Role / Device Role / Timing Role: Low-capacitance TVS placed at connector entry point, referenced to local analog ground. Use Value: Sub-1 ns response prevents transient coupling into precision ADC front-ends; low leakage (<1 µA @ 40 V) avoids signal offset errors. |
Use Scenario: Protecting LIN bus or switch inputs in automotive BCMs exposed to ISO 7637-2 pulse 1/2a/3a transients. IC Role / Device Role / Timing Role: Unidirectional clamp on 12 V supply or signal lines, selected for VRWM >13.5 V nominal battery voltage. Use Value: Rated for -55°C to +150°C operation and qualified to AEC-Q101; clamps 40 A pulses (IEC61000-4-4) without degradation in underhood environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40A | DO-214AC package (larger footprint, 2.5 mm height), 400 W peak power (10/1000 µs), same VRWM and VC. | Preferred where higher surge rating is required and board space permits larger package; less suitable for ultra-thin portable designs. | Select SMAJ40A if 400 W surge capability is mandatory and SOD-123FL size constraint does not apply. |
| 1.5SMC40A | DO-214AB package (5.3 mm × 4.5 mm), 1500 W peak power (10/1000 µs), higher thermal mass, same VRWM/VC specs. | Used in high-energy industrial power systems where PCB layout accommodates larger footprints and higher reliability margins are needed. | Choose 1.5SMC40A only when >200 W surge handling is required and SOD-123FL's compactness is not critical. |
Compared with SMAJ40A and 1.5SMC40A, the SMF40AT1G delivers identical electrical protection performance in a significantly smaller SOD-123FL package - making it optimal for space-constrained, high-volume consumer and portable electronics where 200 W surge immunity suffices.
Availability
SMF40AT1G is available at Aetrix Electronics and suitable for USB power input protection, DC power supply rail protection, and industrial sensor interface protection requiring stable component supply across high-mix production runs.
Supply support for SMF40AT1G 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 IoT applications.
The SMF series belongs to onsemi's transient voltage suppressor product line, engineered specifically for compact, high-reliability ESD and surge protection in space- and cost-sensitive electronic systems.
FAQ
What is the working peak reverse voltage (VRWM) of the SMF40AT1G?
The SMF40AT1G has a VRWM of 40 V, meaning it remains non-conductive up to this reverse voltage level under normal operation. This value is critical for selecting a TVS that avoids leakage or false triggering on circuits with nominal 36–40 V rails, such as 48 V telecom systems with derating. The SMF40AT1G will begin clamping only when transient voltage exceeds its specified breakdown range (44.4–49.1 V).
Does the SMF40AT1G meet IEC61000-4-2 and IEC61000-4-4 standards?
Yes, the SMF40AT1G is rated for IEC61000-4-2 Level 4 ESD protection (>16 kV contact discharge) and IEC61000-4-4 surge immunity (40 A, 5/50 ns waveform). These certifications are validated per onsemi's official datasheet and confirm suitability for end-equipment requiring compliance with international EMC standards - including consumer electronics, industrial HMIs, and automotive body electronics where the SMF40AT1G serves as first-line transient defense.
What is the maximum clamping voltage (VC) of the SMF40AT1G at its rated peak pulse current?
The SMF40AT1G exhibits a maximum clamping voltage (VC) of 64.5 V when subjected to its rated 64.5 A peak pulse current (10/1000 µs waveform). This VC value defines the upper voltage limit imposed on protected circuitry during worst-case surge events. Designers must ensure downstream components (e.g., USB controllers, LDOs) have absolute maximum voltage ratings exceeding 64.5 V to prevent damage - a key validation step when using the SMF40AT1G in system-level protection schemes.
Is the SMF40AT1G compatible with lead-free reflow soldering processes?
Yes, the SMF40AT1G is Pb-free and qualified for lead-free reflow soldering at peak temperatures up to 260°C, meeting J-STD-020 MSL 1 requirements. Its matte tin lead finish ensures reliable wetting and intermetallic formation during standard SAC305 reflow profiles. The "G" suffix explicitly denotes this Pb-free construction, making the SMF40AT1G compliant with RoHS directives and suitable for modern high-volume SMT assembly lines without process modification.
How does the SOD-123FL package of the SMF40AT1G compare to DO-214AC in terms of board space and thermal performance?
The SOD-123FL package of the SMF40AT1G occupies just 8.45 mm² with a maximum height of 1.0 mm - roughly 60% smaller in footprint and half the height of the DO-214AC (SMAJ series). Thermally, its junction-to-ambient resistance is 325 °C/W on FR-4 (with recommended pad), versus ~150 °C/W for DO-214AC. Thus, while the SMF40AT1G saves significant PCB area, designers must verify thermal limits under sustained surge conditions or high ambient temperatures, especially when replacing larger-package alternatives like SMAJ40A with the SMF40AT1G.
SMF40AT1G 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):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 3.1A
- 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
SMF40AT1G FAQ
1.How can I place an order for SMF40AT1G through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF40AT1G 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 SMF40AT1G reliable?
The price and inventory of SMF40AT1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF40AT1G is usually 5 days.
3.What payment methods are accepted for SMF40AT1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF40AT1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF40AT1G?
SMF40AT1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF40AT1G 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 SMF40AT1G?
For technical support, including SMF40AT1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF40AT1G requirements.
6.How does Aetrix verify that SMF40AT1G is sourced from the original manufacturer or authorized distributors?
All SMF40AT1G 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 SMF40AT1G meets industry standards.
7.What is the process for return or replacement of SMF40AT1G?
All SMF40AT1G units undergo pre-shipment inspection (PSI). If there is an issue with SMF40AT1G, 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 SMF40AT1G part is unused and in its original packaging.
Return procedure for SMF40AT1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF40AT1G Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
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D5V0L1B2WS-7
Diodes Incorporated
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