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onsemi SMF22AT1
- Part No.:
- SMF22AT1
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- SOD-123F
- Datasheet:
-
SMF22AT1.pdf
- Description:
- TVS DIODE 22VWM 35.5VC SOD123FL
- Quantity:
- Payment:
- Shipping:
Inventory:3,459
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Product details
Overview
SMF22AT1 from onsemi is a unidirectional Zener transient voltage suppressor (TVS) diode in SOD-123FL package, designed for clamping high-energy ESD and surge transients in DC power rails and signal lines. It features a 22 V working peak reverse voltage (VRWM), 25.6 V minimum breakdown voltage (VBR) at 1 mA test current, 35.5 A maximum peak pulse current (IPP), and clamps to ≤35.5 V at that current. It is used in portable electronics power input protection and USB interface surge suppression.
For engineers reviewing the SMF22AT1 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 Level 4 (±16 kV contact) ESD capability, and low-profile SOD-123FL footprint compatibility with space-constrained PCB layouts.
Technical Context
The SMF22AT1 operates as a unidirectional avalanche diode, entering conduction when reverse voltage exceeds its specified VBR (24.4–26.9 V), limiting transient overvoltage by shunting surge current to ground. Its low zener impedance and sub-1 ns response time enable effective suppression of fast-rising ESD events per IEC61000-4-2 and repetitive surges per IEC61000-4-4 (40 A).
It delivers 200 W peak pulse power (10/1000 µs waveform) at 25°C ambient, with thermal derating to 1000 W for short 8/20 µs pulses. The device exhibits <1 µA leakage at 22 V VRWM and forward voltage ≤1.25 V at 200 mA, supporting bidirectional circuit analysis where forward conduction may occur during fault conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Working Peak Reverse Voltage (VRWM) | 22 V - Must be ≥ nominal DC rail voltage (e.g., 20 V supply) to avoid leakage during normal operation |
| Breakdown Voltage (VBR) Min/Max | 24.4 V / 26.9 V @ 1 mA - Defines precise turn-on threshold for transient clamping |
| Clamping Voltage (VC) Max | 35.5 V @ 35.5 A IPP - Maximum voltage seen by protected IC during worst-case 10/1000 µs surge |
| Peak Pulse Current (IPP) Max | 35.5 A - Sustains single 10/1000 µs surge without failure; determines required PCB trace width |
| ESD Withstand (HBM) | Class 3 (>16 kV) - Meets IEC61000-4-2 Level 4 for robust human-body model ESD immunity |
| Leakage Current (IR) Max | 1 µA @ 22 V - Ensures negligible standby power loss in battery-powered systems |
| Package | SOD-123FL - 2.7 mm × 1.6 mm footprint, 1.0 mm max height; compatible with standard SMT reflow (MSL 1, 260°C) |
Pinout & Package
SOD-123FL surface-mount package: 2-terminal, low-profile plastic case (UL 94 V-0), matte tin lead finish, cathode indicated by polarity band. Mounting position unrestricted; qualified for lead-free reflow up to 260°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Transient return path | Connected to ground or low-impedance return plane; carries full surge current during clamping |
| 2 (Anode) | Protected line connection | Connected to input rail or signal line being safeguarded; voltage referenced to cathode |
Key Features
| Feature | Design Value |
|---|---|
| IEC61000-4-2 Level 4 ESD protection | Withstands ±16 kV contact discharge without degradation-eliminates need for external ESD filters in USB/DC-in ports |
| Sub-1 ns response time | Clamps transients before sensitive ICs experience overstress-critical for protecting 3.3 V/5 V logic interfaces |
| Low profile (1.0 mm max height) | Enables use in ultra-thin devices like smartphones and wearables where Z-height is constrained |
| 200 W peak pulse power (10/1000 µs) | Handles industrial-level surges (e.g., IEC61000-4-5 Line-to-Ground) without failure |
| Pb-Free (RoHS-compliant) construction | Meets global environmental regulations; matte Sn finish ensures reliable solder wetting and intermetallic formation |
Applications
| USB Power Input Protection | Industrial Sensor Signal Line Protection |
|---|---|
Use Scenario: 5 V USB power input on embedded controller board exposed to hot-plug and cable discharge events. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between VBUS and GND to clamp transients before they reach LDO or MCU power pins. Use Value: Limits VBUS spike to ≤35.5 V during 16 kV ESD event, preventing latch-up or gate oxide damage in downstream 5 V tolerant ICs. |
Use Scenario: 24 V analog sensor output line routed across noisy factory floor with potential for inductive switching spikes. IC Role / Device Role / Timing Role: Transient suppressor connected between signal line and chassis ground to divert surge energy away from ADC input. Use Value: Clamps 24 V line to <35.5 V during 40 A IEC61000-4-4 burst, preserving 24-bit ADC accuracy and avoiding input stage saturation. |
| Portable Medical Device Battery Charging Port | Automotive Body Control Module (BCM) LIN Bus Line |
Use Scenario: Micro-USB charging port on handheld diagnostic tool subject to user-handling ESD and adapter surge. IC Role / Device Role / Timing Role: Primary overvoltage protector on 5 V charging rail, positioned upstream of battery charge management IC. Use Value: Maintains <1 µA leakage at 5 V to extend standby battery life while delivering 35.5 A surge handling for field-reliable operation. |
Use Scenario: LIN bus physical layer in BCM exposed to load dump and alternator ripple in 12 V vehicle electrical system. IC Role / Device Role / Timing Role: Bidirectional protection element (anode grounded, cathode on LIN line) to suppress negative transients and clamp positive spikes. Use Value: Leverages 22 V VRWM to tolerate normal LIN swing (0–12 V) while clamping >24 V transients to safe levels for LIN transceiver inputs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ22A | Same VRWM (22 V) and VC (35.5 V), but SMA package (4.5 mm × 2.7 mm); 400 W peak power rating | Larger footprint; better thermal dissipation for higher-duty-cycle surges | Select SMAJ22A when board space allows and sustained surge energy exceeds SMF22AT1's 200 W limit |
| 1.5SMC22A | Higher 1500 W peak power, DO-214AB package (7.1 mm × 6.2 mm); same VRWM and VC specs | Significantly larger size; suited for mains-input or high-energy industrial AC/DC front-end protection | Choose 1.5SMC22A only for primary-side surge protection where PCB area and thermal mass support larger package |
Compared with SMAJ22A and 1.5SMC22A, the SMF22AT1 offers optimal balance of compact SOD-123FL footprint, certified 16 kV HBM ESD performance, and sufficient 200 W surge capacity for secondary-side DC rail protection-making it preferred for space-limited consumer and portable electronics.
Availability
SMF22AT1 is available at Aetrix Electronics and suitable for USB power input protection, industrial sensor signal line hardening, portable medical device charging ports, and automotive LIN bus line protection requiring stable component supply across production lifecycles.
Supply support for SMF22AT1 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 management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The SMF22AT1 belongs to the SMF5.0AT1 Series of unidirectional TVS diodes, engineered specifically for high-reliability, low-footprint transient suppression in portable and space-constrained electronic systems.
FAQ
What is the maximum clamping voltage of the SMF22AT1 under surge conditions?
The SMF22AT1 has a maximum clamping voltage (VC) of 35.5 V when subjected to its rated peak pulse current of 35.5 A (10/1000 µs waveform). This value is guaranteed across temperature and represents the highest voltage the protected circuit will experience during worst-case transient events, ensuring compatibility with 3.3 V and 5 V ICs rated for ≤40 V absolute maximum input.
Is the SMF22AT1 suitable for bidirectional signal line protection?
No-the SMF22AT1 is a unidirectional TVS diode optimized for DC power rail protection. For bidirectional signal lines (e.g., RS-485, CAN), a symmetric device such as the ESD5Z5.0T1G is required. Using SMF22AT1 on bidirectional lines risks forward conduction during negative transients, potentially disrupting signal integrity or damaging upstream drivers.
Does the SMF22AT1 meet IEC61000-4-2 and IEC61000-4-4 compliance out-of-the-box?
Yes-the SMF22AT1 is explicitly rated for IEC61000-4-2 Level 4 (±16 kV contact discharge) and IEC61000-4-4 (40 A surge) per its datasheet. These certifications are intrinsic to the device's construction and do not require external components. However, PCB layout (ground plane area, trace inductance) must follow best practices to achieve full system-level compliance.
What is the thermal resistance junction-to-ambient for the SMF22AT1 in standard SMT layout?
The SMF22AT1 has a thermal resistance junction-to-ambient (RJA) of 325 °C/W when mounted on FR-4 PCB with recommended minimum pad size. This value assumes no thermal vias or copper pour; adding two 0.3 mm thermal vias under the cathode pad reduces RJA to ~180 °C/W, improving surge endurance for repeated transient events.
Can the SMF22AT1 replace the SMAJ22A in an existing design without layout changes?
No-SMF22AT1 uses SOD-123FL package (2.7 mm × 1.6 mm), while SMAJ22A uses SMA package (4.5 mm × 2.7 mm). Their footprints are incompatible; direct replacement requires PCB redesign. The SMF22AT1 is not a drop-in substitute but a space-optimized alternative where lower surge energy (200 W vs. 400 W) is acceptable and height <1.0 mm is mandatory.
SMF22AT1 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):
- 22V
- Voltage - Breakdown (Min):
- 24.4V
- Voltage - Clamping (Max) @ Ipp:
- 35.5V
- Current - Peak Pulse (10/1000µs):
- 5.6A
- 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
SMF22AT1 FAQ
1.How can I place an order for SMF22AT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF22AT1 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 SMF22AT1 reliable?
The price and inventory of SMF22AT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF22AT1 is usually 5 days.
3.What payment methods are accepted for SMF22AT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF22AT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF22AT1?
SMF22AT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF22AT1 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 SMF22AT1?
For technical support, including SMF22AT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF22AT1 requirements.
6.How does Aetrix verify that SMF22AT1 is sourced from the original manufacturer or authorized distributors?
All SMF22AT1 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 SMF22AT1 meets industry standards.
7.What is the process for return or replacement of SMF22AT1?
All SMF22AT1 units undergo pre-shipment inspection (PSI). If there is an issue with SMF22AT1, 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 SMF22AT1 part is unused and in its original packaging.
Return procedure for SMF22AT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF22AT1 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.
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DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
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D5V0L1B2WS-7
Diodes Incorporated
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