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onsemi SMF8.5AT1
- Part No.:
- SMF8.5AT1
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- SOD-123F
- Datasheet:
-
SMF8.5AT1.pdf
- Description:
- TVS DIODE 8.5VWM 14.4VC SOD123FL
- Quantity:
- Payment:
- Shipping:
Inventory:4,573
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Product details
Overview
SMF8.5AT1 from onsemi is a unidirectional transient voltage suppressor diode (TVS) designed for overvoltage protection in DC power rails and signal lines. It features a working peak reverse voltage of 8.5 V, clamping voltage of 14.4 V at 13.9 A peak pulse current, 200 W peak pulse power (10/1000 µs), <1 ns response time, and IEC61000-4-2 Level 4 ESD immunity (>16 kV HBM). It is used in portable power supplies and USB interface protection.
For engineers reviewing the SMF8.5AT1 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ circuit operating voltage, VC margin relative to IC absolute maximum ratings, surge current capability under IEC61000-4-4 40 A transients, thermal derating on FR-4 PCBs, and SOD−123FL footprint compatibility with high-density layouts.
Technical Context
The SMF8.5AT1 operates as a Zener-based clamping device, entering avalanche breakdown when reverse voltage exceeds its 9.44–10.4 V breakdown range (at 1 mA test current). Its low zener impedance ensures stable clamping during fast transients such as ESD or inductive switching spikes.
It is rated for non-repetitive 10/1000 µs surges up to 200 W and 8/20 µs surges up to 1000 W, with thermal resistance RθJA = 325 °C/W on recommended FR-4 pad layout. The device meets MSL 1 and supports reflow up to 260 °C for 10 s.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 8.5 V - Maximum continuous reverse operating voltage before clamping begins; must exceed system DC rail or signal swing. |
| VBR (min/max) | 9.44 V / 10.4 V @ 1 mA - Confirmed breakdown threshold range; defines turn-on consistency across temperature and unit variation. |
| VC @ IPP | 14.4 V @ 13.9 A - Clamped voltage during 10/1000 µs surge; determines protected IC's stress level during worst-case transient. |
| IPP | 13.9 A - Peak pulse current supported at rated clamping voltage; validates compliance with IEC61000-4-4 40 A surge testing margin. |
| Response Time | <1 ns - Enables suppression of sub-nanosecond ESD events before downstream ICs experience latch-up or damage. |
| ESD Rating | >16 kV HBM, IEC61000-4-2 Level 4 - Qualifies for direct interface protection in consumer handhelds and industrial I/O ports. |
| Package | SOD−123FL - Surface-mount, low-profile (1.0 mm max height), 8.45 mm² footprint; compatible with automated pick-and-place and standard reflow profiles. |
Pinout & Package
SOD−123FL package: 2-terminal surface-mount diode with cathode indicated by polarity band. Dimensions: 1.50–1.80 mm (L) × 2.50–2.90 mm (W) × ≤1.00 mm (H); lead finish = 100% matte tin; MSL 1; qualified for 260 °C reflow.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to protected node's higher-potential side (e.g., VBUS, VIN); carries surge current into ground path during clamping. |
| 2 (Non-banded End) | Anode | Connected to system ground or return path; completes conduction loop during transient; requires low-inductance grounding for effective suppression. |
Key Features
| Feature | Design Value |
|---|---|
| Low Clamping Ratio | VC/VRWM = 1.69 - Minimizes overvoltage stress on downstream ICs while maintaining margin above normal operating voltage. |
| Ultra-Fast Response | <1 ns turn-on - Captures ESD and fast-rising transients before propagation into sensitive analog or digital circuitry. |
| High Surge Robustness | 200 W @ 10/1000 µs - Withstands repeated lightning-induced surges in industrial power inputs without degradation. |
| Small Footprint Protection | 8.45 mm² area - Enables TVS integration directly at connector or IC pin without board space penalty in compact portable designs. |
| ESD + EFT Dual Compliance | IEC61000-4-2 Level 4 + IEC61000-4-4 40 A - Single-device coverage for both human-body and electrical-fast-transient immunity requirements. |
Applications
| USB Power Input Protection | Smartphone Battery Charging Circuit |
|---|---|
Use Scenario: 5 V USB port exposed to hot-plug transients and cable ESD events. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VBUS and GND to clamp surges before reaching USB controller or charging IC. Use Value: Limits VBUS spike to ≤14.4 V during 13.9 A transient, preventing damage to 5.5 V-rated USB PHY and ensuring uninterrupted enumeration. | Use Scenario: Li-ion battery charger input subjected to automotive-grade load dump and reverse polarity faults. IC Role / Device Role / Timing Role: Primary overvoltage clamp on input rail upstream of buck converter and battery management IC. Use Value: Absorbs 200 W surge energy within 1 ms, holding rail voltage below 14.4 V to avoid triggering charger IC shutdown or damaging internal FETs. |
| Industrial Sensor Signal Line | POS Terminal Keypad Interface |
Use Scenario: 3.3 V analog sensor output line routed across noisy factory floor with long cables. IC Role / Device Role / Timing Role: Low-capacitance TVS on differential or single-ended signal path to suppress coupled EFT and lightning-induced surges. Use Value: Clamps induced transients to ≤14.4 V without distorting 3.3 V signal integrity due to <1 ns response and minimal leakage (<10 µA @ 8.5 V). | Use Scenario: Keypad matrix rows/columns connected to microcontroller GPIOs in retail terminals exposed to customer ESD. IC Role / Device Role / Timing Role: Point-of-failure protection on each keypad line to prevent ESD-induced MCU reset or I/O latch-up. Use Value: Provides >16 kV HBM and IEC61000-4-2 Level 4 immunity, enabling reliable operation after repeated 8 kV contact discharges per EN61000-4-2. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ8.5A | Same VRWM (8.5 V) and VC (14.4 V), but SMA package (larger footprint, higher RθJA = 40°C/W) | Lower power density; less suitable for ultra-compact layouts; better thermal dissipation on large copper pours | Select SMAJ8.5A only if board space allows larger 2.5 × 4.5 mm package and higher thermal mass is needed for repetitive surges. |
| P6SMB8.5A | Higher Ppk (600 W @ 10/1000 µs), same VRWM, but DO-214AA package (5.3 × 4.2 mm, 1.75 mm height) | Designed for higher-energy industrial transients; incompatible with fine-pitch SMT assembly | Choose P6SMB8.5A when surge threat exceeds 200 W and manual or wave-solder assembly is acceptable. |
Compared with SMAJ8.5A and P6SMB8.5A, the SMF8.5AT1 delivers identical clamping performance in the smallest possible footprint (SOD−123FL), making it optimal for space-constrained consumer electronics where board real estate and automated assembly efficiency are critical.
Availability
SMF8.5AT1 is available at Aetrix Electronics and suitable for USB power protection, smartphone charging circuits, industrial sensor interfaces, and POS terminal keypad protection requiring stable component supply and full traceability.
Supply support for SMF8.5AT1 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 SMF5.0AT1 Series is part of onsemi's transient voltage suppressor portfolio, engineered specifically for high-speed, low-footprint overvoltage protection in portable and high-density electronic systems.
FAQ
What is the working peak reverse voltage (VRWM) of the SMF8.5AT1?
The SMF8.5AT1 has a working peak reverse voltage (VRWM) of 8.5 V, meaning it remains non-conductive up to this DC or peak AC voltage level. This value is selected to be equal to or slightly greater than the nominal operating voltage of the protected circuit-such as a 5 V or 3.3 V rail with tolerance margin-to ensure no leakage or false triggering during normal operation while still providing robust clamping during transients.
How does the SMF8.5AT1 compare to the SMF8.0AT1 in terms of clamping performance?
The SMF8.5AT1 exhibits a higher breakdown voltage range (9.44–10.4 V vs. 8.89–9.83 V for SMF8.0AT1) and a correspondingly higher clamping voltage (14.4 V vs. 13.6 V at respective IPP). Its peak pulse current is 13.9 A versus 14.7 A for SMF8.0AT1, reflecting a trade-off between voltage rating and surge capacity. Both share identical SOD−123FL packaging and thermal characteristics, making them drop-in replacements only when VRWM alignment matches system requirements.
Can the SMF8.5AT1 be used for bidirectional transient suppression?
No, the SMF8.5AT1 is a unidirectional TVS diode, optimized for clamping positive transients on grounded systems. It conducts only when reverse-biased beyond VRWM and does not protect against positive surges on the anode side. For bidirectional protection-such as AC lines or floating data buses-a dedicated bidirectional device like SMBJ8.5CA or two back-to-back SMF8.5AT1 units would be required; using a single SMF8.5AT1 in bidirectional configurations risks failure or incomplete protection.
What is the maximum allowable soldering temperature and duration for the SMF8.5AT1?
The SMF8.5AT1 is qualified for reflow soldering at a peak temperature of 260 °C for up to 10 seconds, consistent with IPC/JEDEC J-STD-020 moisture sensitivity level (MSL) 1 requirements. Preheating is mandatory to limit thermal gradient; the delta between preheat and soldering temperature must not exceed 100 °C, and the maximum temperature gradient during ramp-up must stay ≤5 °C/s. Exceeding these limits risks internal delamination or bond wire failure.
Does the SMF8.5AT1 meet IEC61000-4-5 surge immunity standards?
The SMF8.5AT1 is rated for 200 W peak pulse power under the 10/1000 µs waveform defined in IEC61000-4-5 Annex A, but it is not certified to the full system-level 4 kV/2 Ω combination wave test. It provides foundational component-level surge handling and must be combined with additional filtering (e.g., common-mode chokes, series resistors) and proper PCB layout (short traces, ground plane) to achieve full IEC61000-4-5 compliance in end equipment. Its primary certification is IEC61000-4-2 (ESD) and IEC61000-4-4 (EFT).
SMF8.5AT1 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):
- 8.5V
- Voltage - Breakdown (Min):
- 9.44V
- Voltage - Clamping (Max) @ Ipp:
- 14.4V
- Current - Peak Pulse (10/1000µs):
- 13.9A
- 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
SMF8.5AT1 FAQ
1.How can I place an order for SMF8.5AT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF8.5AT1 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 SMF8.5AT1 reliable?
The price and inventory of SMF8.5AT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF8.5AT1 is usually 5 days.
3.What payment methods are accepted for SMF8.5AT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF8.5AT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF8.5AT1?
SMF8.5AT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF8.5AT1 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 SMF8.5AT1?
For technical support, including SMF8.5AT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF8.5AT1 requirements.
6.How does Aetrix verify that SMF8.5AT1 is sourced from the original manufacturer or authorized distributors?
All SMF8.5AT1 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 SMF8.5AT1 meets industry standards.
7.What is the process for return or replacement of SMF8.5AT1?
All SMF8.5AT1 units undergo pre-shipment inspection (PSI). If there is an issue with SMF8.5AT1, 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 SMF8.5AT1 part is unused and in its original packaging.
Return procedure for SMF8.5AT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF8.5AT1 Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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ESD5Z3.3T1G
onsemi
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D5V0H1B2LP-7B
Diodes Incorporated
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D5V0P1B2LP-7B
Diodes Incorporated
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DESD5V0U1BA-7
Diodes Incorporated
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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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