My Inquiry
My Account
onsemi SMF12AT1
- Part No.:
- SMF12AT1
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- SOD-123F
- Datasheet:
-
SMF12AT1.pdf
- Description:
- TVS DIODE 12VWM 19.9VC SOD123FL
- Quantity:
- Payment:
- Shipping:
Inventory:5,578
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMF12AT1 from onsemi is a unidirectional transient voltage suppressor (TVS) diode designed for overvoltage protection in DC power rails and signal lines. It features a 12 V working peak reverse voltage (VRWM), 19.9 A maximum peak pulse current (IPP), 19.9 V clamping voltage (VC) at IPP, and <1 ns response time. It is used in portable electronics power input stages to absorb ESD and surge events per IEC61000-4-2 Level 4 and IEC61000-4-4.
For engineers reviewing the SMF12AT1 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM matching system operating voltage, VC margin relative to protected IC absolute maximum ratings, SOD−123FL footprint compatibility, and 200 W peak pulse power rating for 10/1000 µs transients.
Technical Context
The SMF12AT1 operates as a Zener-based clamping device, entering avalanche breakdown when reverse voltage exceeds its 13.3–14.7 V breakdown range (VBR @ IT = 1 mA). Its low zener impedance ensures stable clamping during fast transients, with typical leakage current ≤2.5 µA at 12 V VRWM.
It is rated for 200 W peak pulse power (10/1000 µs waveform), 1000 W at 8/20 µs, and supports reflow up to 260°C. Thermal resistance from junction to ambient is 325°C/W on FR-4 with recommended pad layout, enabling reliable operation from −55°C to +150°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 12 V - Maximum continuous reverse voltage before clamping begins; must be ≥ circuit's DC operating voltage. |
| VBR (min/max) | 13.3 V / 14.7 V - Breakdown occurs within this range at 1 mA test current; defines turn-on threshold tolerance. |
| VC @ IPP | 19.9 V - Clamped voltage seen by protected circuit during 19.9 A transient; determines stress on downstream components. |
| IPP | 19.9 A - Peak current the device safely shunts for 10/1000 µs waveform; defines surge handling capacity. |
| Response Time | <1 ns - Enables suppression of nanosecond-scale ESD events before sensitive circuitry is damaged. |
| ESD Rating | >16 kV HBM - Meets Class 3 human body model; qualifies for direct interface with user-accessible ports. |
| Package | SOD−123FL - Surface-mount, 2-pin, 1.0 mm max height; compatible with automated assembly and space-constrained PCBs. |
Pinout & Package
SOD−123FL is a 2-terminal surface-mount package with cathode indicated by a polarity band. The device has no internal circuitry beyond the Zener junction; terminals serve only as anode and cathode connections for unidirectional clamping.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to system ground or lower-potential rail; reverse-biased during normal operation; conducts during overvoltage. |
| 2 (Non-banded End) | Anode | Connected to protected line (e.g., VBUS, USB_VCC); carries transient current to ground via cathode during clamping. |
Key Features
| Feature | Design Value |
|---|---|
| Low-profile SOD−123FL package | 1.0 mm max height enables use in ultra-thin portable devices like smartphones and wearables. |
| IEC61000−4−2 Level 4 compliance | Withstands ±8 kV contact / ±15 kV air discharge without degradation-meets industrial and consumer ESD requirements. |
| Fast response <1 ns | Clamps transients before propagation into IC inputs, protecting high-speed interfaces such as USB 2.0 and HDMI hot-plug circuits. |
| 200 W peak pulse power (10/1000 µs) | Handles common surge events in 5–24 V DC power distribution networks without failure. |
| Low leakage <2.5 µA @ VRWM | Minimizes standby power loss in battery-powered systems; avoids false triggering in high-impedance sensing nodes. |
Applications
| USB Power Input Protection | Automotive Body Control Module (BCM) Sensors |
|---|---|
Use Scenario: Protecting 5 V USB VBUS line from ESD and load dump-induced transients in portable chargers and accessories. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VBUS and GND, clamping surges before they reach USB controller or charging IC. Use Value: Prevents latch-up or permanent damage to USB PHY and PMIC under ±8 kV contact ESD per IEC61000-4-2, with 19.9 V clamping limiting stress below 20 V absolute max ratings. |
Use Scenario: Safeguarding 12 V sensor supply lines (e.g., temperature, humidity) in automotive BCMs exposed to ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Standoff-rated TVS on 12 V rail, absorbing coupled transients from relay switching or alternator load dump. Use Value: Withstands 200 W 10/1000 µs surges while maintaining 12 V VRWM alignment with nominal vehicle battery voltage, ensuring no false triggering during cranking (6.5–9 V). |
| Industrial PLC Digital I/O Protection | Smartphone Front-Facing Camera Module |
Use Scenario: Shielding 24 V digital input channels from field-wiring induced surges in factory automation controllers. IC Role / Device Role / Timing Role: Primary overvoltage clamp on dry-contact input, placed upstream of optocoupler or Schmitt trigger input stage. Use Value: Limits transient voltage to ≤19.9 V, keeping input stage within safe operating area while supporting >100,000 surge cycles due to robust Zener structure. |
Use Scenario: Guarding 1.8 V or 2.8 V camera module power and data lines (e.g., MIPI D-PHY) against ESD during board handling and connector mating. IC Role / Device Role / Timing Role: Low-capacitance TVS on VDD_IO and data lanes, leveraging SOD−123FL's minimal parasitic capacitance (~50 pF @ 0 V). Use Value: Provides >16 kV HBM ESD immunity without distorting high-speed signals, thanks to sub-1 ns response and compact footprint preserving trace integrity. |
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) and VC (20.1 V), but SMA package (larger footprint, 2.4 mm height) and 400 W peak power rating. | Better suited for higher-energy surges; less suitable for ultra-thin or dense layouts where SOD−123FL height constraint applies. | Select SMAJ12A only if surge energy exceeds 200 W capability and board space allows larger package. |
| P6SMB12A | Same VRWM (12 V) and VC (19.9 V), but SMB package (3.5 mm width, 2.3 mm height) and 600 W peak power rating. | Higher thermal mass improves reliability in high-temperature environments (>85°C ambient), but incompatible with fine-pitch SMT processes optimized for SOD−123FL. | Choose P6SMB12A for industrial power supplies requiring extended surge endurance and higher TJ derating margin. |
Compared with SMAJ12A and P6SMB12A, the SMF12AT1 offers the smallest form factor and lowest profile among 12 V TVS diodes, making it optimal for space- and height-constrained designs-though its 200 W rating requires careful surge energy budgeting versus the higher-power alternatives.
Availability
SMF12AT1 is available at Aetrix Electronics and suitable for USB power delivery, automotive sensor interfaces, industrial PLC I/O, and smartphone peripheral protection requiring stable component supply and consistent SOD−123FL packaging.
Supply support for SMF12AT1 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, sensors, and logic solutions for automotive, industrial, and consumer markets.
The SMF series belongs to onsemi's transient voltage suppressor product line, engineered specifically for compact, high-reliability overvoltage protection in portable and space-constrained electronic systems.
FAQ
What is the working peak reverse voltage (VRWM) of the SMF12AT1?
The SMF12AT1 has a VRWM of 12 V, meaning it remains non-conductive up to this reverse voltage during normal operation. This value is selected to match standard 12 V DC systems while providing sufficient margin above nominal supply to avoid leakage or premature conduction during ripple or brownout conditions. The SMF12AT1 maintains this rating across its full operating temperature range.
How does the SMF12AT1 differ from bidirectional TVS diodes?
The SMF12AT1 is unidirectional and functions only under reverse bias-clamping positive transients on the anode side relative to cathode. Unlike bidirectional variants, it does not suppress negative-going transients on the same node. This makes the SMF12AT1 ideal for DC power rail protection where polarity is fixed, offering tighter VBR control and lower leakage than bidirectional equivalents.
Can the SMF12AT1 be used in automotive applications meeting AEC-Q200?
The SMF12AT1 is not AEC-Q200 qualified. While it operates from −55°C to +150°C and meets IEC61000-4-2/4-4, it lacks the stress testing, lot traceability, and qualification documentation required for automotive-grade components. For AEC-Q200-compliant designs, consider onsemi's AEC-Q200-qualified NUP series or equivalent qualified alternatives instead of the SMF12AT1.
What is the maximum clamping voltage (VC) of the SMF12AT1 under surge conditions?
The SMF12AT1 has a maximum clamping voltage (VC) of 19.9 V when subjected to its rated peak pulse current (IPP) of 19.9 A under the 10/1000 µs waveform. This VC value defines the worst-case voltage seen by downstream components during a surge event and must be verified against the absolute maximum ratings of protected ICs to ensure safe operation.
Is the SMF12AT1 compatible with lead-free reflow soldering processes?
Yes, the SMF12AT1 supports lead-free reflow soldering with a qualified maximum reflow temperature of 260°C for up to 10 seconds. Its matte tin lead finish and MSL 1 rating allow unlimited floor life and single reflow exposure without preconditioning. The SOD−123FL package is fully compatible with standard J-STD-020-compliant reflow profiles.
SMF12AT1 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
SMF12AT1 FAQ
1.How can I place an order for SMF12AT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF12AT1 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 SMF12AT1 reliable?
The price and inventory of SMF12AT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF12AT1 is usually 5 days.
3.What payment methods are accepted for SMF12AT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF12AT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF12AT1?
SMF12AT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF12AT1 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 SMF12AT1?
For technical support, including SMF12AT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF12AT1 requirements.
6.How does Aetrix verify that SMF12AT1 is sourced from the original manufacturer or authorized distributors?
All SMF12AT1 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 SMF12AT1 meets industry standards.
7.What is the process for return or replacement of SMF12AT1?
All SMF12AT1 units undergo pre-shipment inspection (PSI). If there is an issue with SMF12AT1, 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 SMF12AT1 part is unused and in its original packaging.
Return procedure for SMF12AT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF12AT1 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
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
