My Inquiry
My Account
onsemi SMF51AT1
- Part No.:
- SMF51AT1
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- SOD-123F
- Datasheet:
-
SMF51AT1.pdf
- Description:
- TVS DIODE 51VWM 82.4VC SOD123FL
- Quantity:
- Payment:
- Shipping:
Inventory:8,425
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMF51AT1 from onsemi is a unidirectional Zener transient voltage suppressor (TVS) diode in SOD−123FL package, designed for overvoltage protection of sensitive electronics. It features a 51 V working peak reverse voltage (VRWM), 62.7 V maximum clamping voltage (VC) at 82.4 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 instrumentation to absorb ESD and lightning-induced surges.
For engineers reviewing the SMF51AT1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, mechanical package details, real-world use cases, and validated alternative parts - all aligned with onsemi's official SMF5.0AT1 Series specification document (Rev. 0, March 2003).
Technical Context
The SMF51AT1 operates as a unidirectional Zener TVS diode, conducting only in reverse breakdown above its VRWM of 51 V. Its clamping behavior is defined by a 1 ms 10/1000 µs surge waveform, with VC = 62.7 V at IPP = 82.4 A and low zener impedance ensuring rapid energy diversion.
It meets IEC61000−4−2 Level 4 (±16 kV HBM) and IEC61000−4−4 (40 A) ESD immunity standards. With <1 ns response time and 1.0 mm max height, it supports high-density PCB layouts in space-constrained applications such as handheld test equipment and battery management modules.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 51 V - Maximum continuous reverse operating voltage before clamping begins; sets minimum system rail tolerance margin. |
| VBR (min) | 56.7 V - Breakdown initiates no earlier than this voltage at 1 mA test current, ensuring reliable turn-on threshold. |
| VC @ IPP | 62.7 V - Clamped voltage seen by protected circuit during 82.4 A transient, defining worst-case stress level. |
| IPP | 82.4 A - Peak surge current the device safely handles per 10/1000 µs waveform without degradation. |
| Leakage @ VRWM | 1 µA - Ultra-low reverse leakage preserves efficiency in always-on 51 V supply monitoring circuits. |
| ESD Rating | Class 3 (>16 kV HBM) - Validated human-body-model ESD robustness for direct interface with user-accessible ports. |
| Package | SOD−123FL - Surface-mount flat-lead plastic case (Case 498), 2.5–2.9 mm length × 1.5–1.8 mm width × ≤1.0 mm height. |
Pinout & Package
SOD−123FL is a 2-terminal surface-mount package with cathode indicated by a polarity band. Mounting position is unrestricted; qualified for 260°C reflow (MSL 1). Recommended footprint: 2.36 mm × 4.19 mm pad layout per onsemi design guidelines.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to protected line (e.g., 51 V rail); conducts when transient exceeds VRWM. |
| 2 (Non-banded End) | Anode | Connected to ground reference; completes clamping path during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| Low-profile SOD−123FL package | Max height 1.0 mm enables stacking under connectors or beneath shields in compact IoT sensor nodes. |
| 200 W peak pulse power (10/1000 µs) | Handles high-energy transients common in 48–60 V industrial control bus lines without derating. |
| Clamping voltage ≤62.7 V at 82.4 A | Ensures downstream 65 V-rated ICs (e.g., ADCs, regulators) remain within absolute maximum ratings during surge. |
| ESD immunity per IEC61000−4−2 Level 4 | Eliminates need for secondary ESD protection on front-panel interfaces of field-deployable instruments. |
| Response time <1 ns | Engages before fast-rising ESD pulses (e.g., ±8 kV contact discharge) can couple into signal paths. |
Applications
| Industrial Sensor Interface | USB-C Power Delivery Monitor |
|---|---|
|
Use Scenario: Protecting analog front-end inputs of 51 V-rated pressure transducers exposed to load-dump transients in factory automation systems. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between sensor output line and ground, clamping surges before they reach precision op-amps. Use Value: Maintains signal integrity by limiting transient overshoot to ≤62.7 V, preventing latch-up in 16-bit SAR ADCs powered from same 51 V rail. |
Use Scenario: Safeguarding CC logic lines and VCONN monitoring circuitry in USB-C PD sink adapters operating near 51 V auxiliary power rails. IC Role / Device Role / Timing Role: Reverse-biased TVS on CC1/CC2 pins, absorbing hot-plug ESD and cable-bend-induced transients. Use Value: Enables compliance with USB PD 3.1 ESD requirements using single-device protection instead of RC+TVS networks, saving board area. |
| Programmable Logic Controller I/O Module | Telecom Remote Power Feeder |
|
Use Scenario: Shielding digital input optocouplers on 24/48/51 V DC input cards from inductive kickback and induced surges on factory floor wiring. IC Role / Device Role / Timing Role: Standoff TVS mounted directly at terminal block entry point, shunting energy before trace inductance amplifies voltage spikes. Use Value: Reduces failure rate of input isolation barriers by limiting clamped voltage to 62.7 V, well below optocoupler CTR degradation thresholds. |
Use Scenario: Protecting monitoring ICs in −51 V remote power feeders used in legacy telecom cabinets with long copper runs susceptible to lightning coupling. IC Role / Device Role / Timing Role: Cathode-to-line TVS on sense resistor feedback path, suppressing common-mode surges entering via twisted-pair feed lines. Use Value: Preserves accuracy of −51 V regulation by preventing transient-induced offset errors in current-sense amplifiers downstream of the TVS. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ51A | Same VRWM (51 V) and VC (64.5 V), but SMA package (larger footprint, 2.5 mm height) and lower IPP (64.5 A). | Less suitable for ultra-thin designs; better thermal dissipation in high-repetition surge environments. | Select SMAJ51A if board space allows larger package and higher steady-state power handling is needed. |
| P6SMB51A | Higher VRWM (51 V), same VC (64.5 V), but DO-214AA package and 1500 W peak power rating (8/20 µs). | Designed for higher-energy lightning surges; not optimized for fast ESD (<1 ns response). | Choose P6SMB51A for AC mains-side protection where 8/20 µs surge immunity dominates over ESD speed. |
Compared with SMAJ51A and P6SMB51A, the SMF51AT1 offers superior board-area efficiency and ESD response speed due to its SOD−123FL form factor and sub-nanosecond turn-on, making it optimal for space-constrained, high-speed interface protection - while SMAJ51A trades size for thermal margin and P6SMB51A targets heavier-duty surge scenarios.
Availability
SMF51AT1 is available at Aetrix Electronics and suitable for industrial sensor interfaces, USB-C power delivery monitors, PLC I/O modules, and telecom remote power feeders requiring stable component supply across multi-year production cycles.
Supply support for SMF51AT1 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, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The SMF51AT1 belongs to the SMF5.0AT1 Series of unidirectional Zener TVS diodes, engineered specifically for compact, high-speed overvoltage protection in DC power rails up to 170 V - balancing low capacitance, fast response, and robust surge handling in minimal footprint.
FAQ
What is the clamping voltage of SMF51AT1 at its rated peak pulse current?
The SMF51AT1 has a maximum clamping voltage (VC) of 62.7 V when subjected to its rated peak pulse current (IPP) of 82.4 A under the standard 10/1000 µs waveform. This value is measured at the device terminals and defines the upper voltage limit imposed on the protected circuit during surge events. The SMF51AT1 maintains this clamping performance consistently across its qualified temperature range of −55°C to +150°C.
Is SMF51AT1 suitable for bidirectional transient suppression?
No, the SMF51AT1 is a unidirectional TVS diode and conducts only in reverse bias above its 51 V VRWM. It does not protect against positive-going transients on grounded lines or AC signals. For bidirectional protection, a pair of SMF51AT1 devices in series opposition or a dedicated bidirectional part like SMBJ51CA would be required. The SMF51AT1 datasheet explicitly specifies "Uni−Directional TVS" in its marking diagram and electrical characterization tables.
What is the maximum operating temperature for SMF51AT1?
The SMF51AT1 has an operating junction temperature range of −55°C to +150°C, as specified in the Maximum Ratings table. Its thermal resistance from junction to ambient (RθJA) is 325°C/W when mounted on the recommended FR-4 footprint. At 25°C ambient, this allows a steady-state power dissipation of 385 mW. Derating curves in Figure 4 confirm usable operation up to 150°C ambient when peak pulse duty cycle remains low.
How does SMF51AT1 compare to SMAJ51A in terms of PCB footprint?
The SMF51AT1 uses the SOD−123FL package (2.5–2.9 mm × 1.5–1.8 mm), occupying ~8.45 mm² footprint area, while the SMAJ51A uses the larger SMA package (4.5 mm × 2.7 mm), requiring ~12.15 mm². This 44% smaller area makes the SMF51AT1 preferable for dense layouts such as portable diagnostic tools or modular PLC I/O cards where board space is constrained. Both share identical VRWM (51 V) and similar clamping performance.
Does SMF51AT1 meet IEC61000−4−2 Level 4 ESD requirements?
Yes, the SMF51AT1 is rated for Class 3 ESD immunity (>16 kV) per the Human Body Model (HBM) and explicitly meets IEC61000−4−2 Level 4 requirements. This is confirmed in the Specification Features section of the official datasheet, which states "ESD Rating of Class 3 (> 16 kV) per Human Body Model" and "IEC61000−4−2 Level 4 ESD Protection". The SMF51AT1 achieves this with sub-1 ns response time and low leakage, making it suitable for protecting exposed ports in field-serviceable equipment.
SMF51AT1 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):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 82.4V
- Current - Peak Pulse (10/1000µs):
- 2.4A
- 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
SMF51AT1 FAQ
1.How can I place an order for SMF51AT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF51AT1 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 SMF51AT1 reliable?
The price and inventory of SMF51AT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF51AT1 is usually 5 days.
3.What payment methods are accepted for SMF51AT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF51AT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF51AT1?
SMF51AT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF51AT1 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 SMF51AT1?
For technical support, including SMF51AT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF51AT1 requirements.
6.How does Aetrix verify that SMF51AT1 is sourced from the original manufacturer or authorized distributors?
All SMF51AT1 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 SMF51AT1 meets industry standards.
7.What is the process for return or replacement of SMF51AT1?
All SMF51AT1 units undergo pre-shipment inspection (PSI). If there is an issue with SMF51AT1, 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 SMF51AT1 part is unused and in its original packaging.
Return procedure for SMF51AT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF51AT1 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…
