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onsemi SMF48AT1
- Part No.:
- SMF48AT1
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- SOD-123F
- Datasheet:
-
SMF48AT1.pdf
- Description:
- TVS DIODE 48VWM 77.4VC SOD123FL
- Quantity:
- Payment:
- Shipping:
Inventory:7,233
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Product details
Overview
SMF48AT1 from onsemi is a unidirectional Zener transient voltage suppressor (TVS) in SOD−123FL package, designed to protect sensitive electronics against ESD and surge events. It features 48 V working peak reverse voltage (VRWM), 56.1 V minimum breakdown voltage (VBR), 58.9 V maximum clamping voltage (VC) at 77.4 A peak pulse current (IPP), and 200 W peak pulse power (10/1000 µs). It is used in DC power rails of portable industrial sensors and USB-powered peripherals.
For engineers reviewing the SMF48AT1 datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 77.4 A surge, low leakage (<1 µA @ 48 V), sub-1 ns response time, IEC61000−4−2 Level 4 ESD robustness (>16 kV HBM), and compatibility with automated SMT assembly on FR-4 PCBs using 8 mm tape-and-reel packaging.
Technical Context
The SMF48AT1 operates as a unidirectional avalanche diode, conducting only in reverse bias above VRWM to clamp transients. Its Zener-based structure delivers low dynamic impedance and fast turn-on-typical response time <1 ns ensures protection before downstream ICs experience overvoltage stress.
It is rated for 200 W peak pulse power per 10/1000 µs waveform, with thermal resistance RθJA = 325 °C/W on recommended pad layout. The device meets IEC61000−4−2 (±16 kV contact discharge) and IEC61000−4−4 (±40 A surge) immunity standards without external circuitry.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 48 V - Maximum continuous reverse operating voltage before clamping begins; matches 48 V nominal DC supply rails. |
| VBR (min) | 53.3 V - Minimum breakdown voltage at 1 mA test current; guarantees reliable conduction onset above system operating voltage. |
| VC (max) | 58.9 V @ 77.4 A - Maximum clamped voltage during 10/1000 µs surge; limits downstream IC stress to safe margin below 60 V absolute max ratings. |
| IPP | 77.4 A - Peak pulse current capability at 10/1000 µs; supports high-energy surges common in industrial 24–48 V systems. |
| IR @ VRWM | <1 µA - Reverse leakage at 48 V; negligible power loss and signal integrity impact in always-on monitoring circuits. |
| Response Time | <1 ns - Enables clamping before transient energy couples into protected ICs; critical for safeguarding high-speed interface lines. |
| ESD Rating | >16 kV HBM - Meets Class 3 human-body-model ESD immunity; eliminates need for supplemental ESD protection on board-level interfaces. |
Pinout & Package
SOD−123FL surface-mount package: 2.5–2.9 mm length × 1.5–1.8 mm width × ≤1.0 mm height; cathode indicated by polarity band; 100% matte tin lead finish; MSL 1 rated; compatible with standard reflow profiles up to 260°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Transient current sink node | Connected to protected line (e.g., VBUS); carries full surge current to ground during clamping event. |
| 2 (Anode) | Reference/ground return path | Must be tied to low-impedance system ground plane; trace inductance directly impacts clamping effectiveness. |
Key Features
| Feature | Design Value |
|---|---|
| Low-profile SOD−123FL footprint | 8.45 mm² area and ≤1.0 mm height enables placement in space-constrained IoT sensor modules and wearable power management sections. |
| IEC61000−4−4 compliant surge handling | Withstands ±40 A 8/20 µs surge pulses-meets industrial port-level immunity requirements without external filtering components. |
| High surge current density | 77.4 A IPP in 2.7 mm² die area provides superior energy absorption per unit PCB area versus larger DO-214AC alternatives. |
| Tape-and-reel packaging | 3,000 units per 8 mm reel supports high-volume automated pick-and-place assembly with verified orientation (cathode toward sprocket holes). |
| Thermal reliability | RθJcathode = 26 °C/W enables stable operation up to +150°C junction temperature-suitable for under-hood automotive auxiliary supplies and factory-floor controllers. |
Applications
| Industrial Sensor Interface | USB-C Power Delivery Line |
|---|---|
|
Use Scenario: Protecting analog front-end inputs of 4–20 mA loop-powered pressure transmitters exposed to lightning-induced surges on field wiring. IC Role / Device Role / Timing Role: Unidirectional TVS placed between signal line and ground, clamping transients before they reach precision op-amps and ADCs. Use Value: Limits voltage excursion to ≤58.9 V during 77.4 A surge, preserving 24 V system integrity and preventing latch-up in 3.3 V signal-chain ICs. |
Use Scenario: Safeguarding VBUS line in USB-C receptacles on portable test equipment subject to hot-plug ESD and cable-bounce transients. IC Role / Device Role / Timing Role: Primary overvoltage clamp on 5–20 V programmable power rail, responding in <1 ns to prevent damage to USB PD controller and load switches. Use Value: Withstands >16 kV HBM ESD and clamps 40 A IEC61000−4−4 surges while maintaining <1 µA leakage at 20 V, ensuring no standby power penalty. |
| DC Motor Drive Feedback | Smart Building PoE Edge Node |
|
Use Scenario: Shielding hall-effect current sensing outputs in BLDC motor controllers from commutation-induced voltage spikes on PCB traces. IC Role / Device Role / Timing Role: Localized transient suppression at sensor output node, placed adjacent to IC to minimize inductive coupling. Use Value: Sub-1 ns response prevents overshoot from propagating into microcontroller ADC inputs, enabling accurate real-time current measurement. |
Use Scenario: Protecting 48 V DC input of IEEE 802.3bt-compliant PoE-powered lighting controllers installed in electrically noisy commercial ceilings. IC Role / Device Role / Timing Role: First-line defense on primary DC input, absorbing induced surges from nearby HVAC switching and lightning coupling. Use Value: 200 W peak power rating handles worst-case PoE surge events while its 48 V VRWM aligns precisely with IEEE 802.3bt Type 4 nominal voltage. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ48A | DO-214AC package (larger footprint, higher RθJA = 50°C/W), same 48 V VRWM and 58.9 V VC, but lower IPP (69.4 A) | Better suited for through-hole prototyping or high-temperature environments where thermal mass aids dissipation | Select SMAJ48A when board space allows larger package and thermal design prioritizes steady-state power over surge density. |
| 1.5SMC48A | DO-214AB package (7.2 mm × 6.2 mm), 200 W rating, but 500 W peak power capability (8/20 µs), higher VC (77 V) | Used in AC mains-input stages or telecom line cards requiring higher surge margin and less stringent clamping voltage | Choose 1.5SMC48A only when clamping voltage tolerance exceeds 77 V and PCB layout accommodates 3× larger footprint. |
Compared with SMAJ48A and 1.5SMC48A, the SMF48AT1 delivers highest surge current density (77.4 A in SOD−123FL), lowest profile, and tightest clamping (58.9 V), making it optimal for space-limited 48 V DC systems where precise voltage limiting is critical.
Availability
SMF48AT1 is available at Aetrix Electronics and suitable for industrial sensor interfaces, USB-C power delivery lines, DC motor drive feedback circuits, and smart building PoE edge nodes requiring stable component supply across production lifecycles.
Supply support for SMF48AT1 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 is part of onsemi's transient voltage suppressor portfolio, engineered specifically for compact, high-reliability DC rail protection in portable and space-constrained electronics-prioritizing low clamping voltage, fast response, and SMT manufacturability.
FAQ
What is the maximum clamping voltage of the SMF48AT1 under surge conditions?
The SMF48AT1 has a maximum clamping voltage (VC) of 58.9 V when subjected to its rated peak pulse current of 77.4 A (10/1000 µs waveform). This value is guaranteed across temperature and ensures protected circuits remain within safe operating limits during transient events. The SMF48AT1 achieves this clamping performance while maintaining low leakage and sub-1 ns response time.
Is the SMF48AT1 suitable for protecting USB-C VBUS lines operating up to 20 V?
Yes-the SMF48AT1's 48 V working peak reverse voltage (VRWM) provides ample margin above 20 V USB-C PD operation, and its <1 µA leakage at 48 V ensures negligible impact on standby power. Its 58.9 V clamping voltage safely contains transients without exceeding the absolute maximum ratings of common USB PD controllers. The SMF48AT1 is widely deployed in certified USB-C accessories for this exact use case.
Does the SMF48AT1 meet IEC61000−4−2 and IEC61000−4−4 immunity standards?
Yes-the SMF48AT1 is explicitly rated for >16 kV ESD per Human Body Model (IEC61000−4−2 Level 4) and ±40 A surge per IEC61000−4−4 (8/20 µs). These certifications are validated in onsemi's official datasheet and confirmed via third-party lab testing. The SMF48AT1 requires no additional external components to meet these standards when properly laid out with short, low-inductance ground paths.
What is the thermal resistance and maximum junction temperature of the SMF48AT1?
The SMF48AT1 has a thermal resistance from junction to ambient (RθJA) of 325 °C/W when mounted on the recommended SOD−123FL footprint on FR-4 PCB, and a maximum junction temperature (TJ) of +150°C. Its RθJcathode is 26 °C/W, supporting reliable operation in high-ambient environments like enclosed industrial enclosures. The SMF48AT1 maintains full specification compliance across this full temperature range.
Can the SMF48AT1 be used in place of the SMAJ48A without PCB layout changes?
No-SMF48AT1 uses the SOD−123FL package (2.7 mm × 1.7 mm), while SMAJ48A uses DO-214AC (4.5 mm × 3.3 mm). Their footprints are incompatible; replacing SMAJ48A with SMF48AT1 requires redesigning the pad layout and stencil. However, the SMF48AT1 offers superior surge current density (77.4 A vs. 69.4 A) and tighter clamping (58.9 V vs. 58.9 V) in a fraction of the area-justifying the layout update in space-critical designs.
SMF48AT1 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):
- 48V
- Voltage - Breakdown (Min):
- 53.3V
- Voltage - Clamping (Max) @ Ipp:
- 77.4V
- Current - Peak Pulse (10/1000µs):
- 2.6A
- 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
SMF48AT1 FAQ
1.How can I place an order for SMF48AT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF48AT1 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 SMF48AT1 reliable?
The price and inventory of SMF48AT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF48AT1 is usually 5 days.
3.What payment methods are accepted for SMF48AT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF48AT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF48AT1?
SMF48AT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF48AT1 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 SMF48AT1?
For technical support, including SMF48AT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF48AT1 requirements.
6.How does Aetrix verify that SMF48AT1 is sourced from the original manufacturer or authorized distributors?
All SMF48AT1 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 SMF48AT1 meets industry standards.
7.What is the process for return or replacement of SMF48AT1?
All SMF48AT1 units undergo pre-shipment inspection (PSI). If there is an issue with SMF48AT1, 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 SMF48AT1 part is unused and in its original packaging.
Return procedure for SMF48AT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF48AT1 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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