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STMicroelectronics SMB6F8.5A
- Part No.:
- SMB6F8.5A
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-221AA, SMB Flat Leads
- Datasheet:
-
SMB6F8.5A.pdf
- Description:
- TVS DIODE 8.5VWM 14.4VC SMBFLAT
- Quantity:
- Payment:
- Shipping:
Inventory:4,873
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Product details
Overview
SMB6F8.5A from STMicroelectronics is a unidirectional 600 W transient voltage suppression (TVS) diode in SMB Flat package, designed for surge protection of sensitive electronics. It features a standoff voltage (VRM) of 8.5 V, clamping voltage (VCL) of 14.4 V at 41.7 A (10/1000 µs), and operates up to 175 °C junction temperature-ideal for automotive power line and industrial I/O interface protection.
For engineers reviewing the SMB6F8.5A datasheet, SMB6F8.5A pinout, SMB6F8.5A application, or SMB6F8.5A equivalent, key selection criteria include clamping performance under 10/1000 µs surges, low leakage (<1 µA at 85 °C), flat-package thermal robustness, and IEC 61000-4-2/4-4 compliance for ESD and EFT immunity.
Technical Context
This TVS diode uses planar silicon technology to achieve stable breakdown behavior and low dynamic resistance (RD = 0.096 Ω at 25 °C, 10/1000 µs), enabling precise voltage clamping during fast transients. Its unidirectional configuration supports DC-biased signal and power lines where reverse conduction must be blocked.
The device delivers 470 W peak pulse power at Tj = 175 °C (10/1000 µs), with thermal impedance optimized for FR4 PCBs using the recommended 5.84 mm × 1.20 mm footprint. Junction capacitance remains below 1000 pF at VR = 0 V (f = 1 MHz), minimizing signal distortion in protected data lines.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 8.5 V - Maximum continuous reverse operating voltage before clamping begins |
| Clamping Voltage (VCL) | 14.4 V at 41.7 A (10/1000 µs) - Peak voltage seen by protected circuit during worst-case surge |
| Peak Pulse Power (PPP) | 600 W (10/1000 µs, Tamb = 25 °C) - Surge energy handling capability under standard waveform |
| Leakage Current (IRM) | 1 µA max at 85 °C - Ensures minimal standby power loss and signal integrity in high-impedance circuits |
| Junction Temperature Range | –55 °C to +175 °C - Supports under-hood automotive and industrial environments without derating |
| ESD Rating | ±30 kV contact/air discharge (IEC 61000-4-2, C = 150 pF/R = 330 Ω) - Full Level 4 immunity without external shielding |
| Dynamic Resistance (RD) | 0.096 Ω at 25 °C - Low impedance limits voltage overshoot during fast-rising transients |
Pinout & Package
SMB6F8.5A is housed in an SMB Flat package (JEDEC MO-213AA), measuring 3.95 mm × 5.60 mm × 1.10 mm with 2.20 mm lead width and 1.20 mm standoff height. The flat profile enables automated placement and improved thermal dissipation on compact PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Marked Band) | Surge current sink | Connected to protected line; conducts transient energy to ground when voltage exceeds VRM |
| Anode | Reference node | Typically tied to system ground or lower-potential rail; completes clamping path during overvoltage events |
Key Features
| Feature | Design Value |
|---|---|
| Planar silicon construction | Enables stable VBR tolerance (±5%), low leakage, and long-term reliability at 175 °C junction temperature |
| Flat 1 mm profile | Reduces board space and improves airflow cooling; compatible with IPC7531 footprint for automated assembly |
| Matte tin-plated leads | Ensures solderability per J-STD-002/E3 and whisker resistance per JESD-201 Class 2 |
| IEC 61000-4-4 Level 4 compliance | Withstands 4 kV EFT bursts on power/signal lines without degradation or latch-up |
Applications
| Automotive Power Line Protection | Industrial PLC Digital I/O |
|---|---|
Use Scenario: Protecting 12 V battery-fed ECUs against load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Unidirectional TVS placed between power rail and chassis ground to clamp transients within safe voltage margins. Use Value: Clamps to 14.4 V at 41.7 A, preventing damage to downstream regulators and microcontrollers during 10/1000 µs surges. | Use Scenario: Shielding 24 V digital input modules from field-wiring induced surges and ESD events. IC Role / Device Role / Timing Role: Primary front-end protection element on isolated input channels, mounted directly at connector entry point. Use Value: Delivers ±30 kV ESD immunity and 4 kV EFT protection while maintaining <1 µA leakage at elevated ambient temperatures. |
| Telecom Interface Protection | Medical Sensor Signal Conditioning |
Use Scenario: Safeguarding RS-485 transceivers connected to outdoor cabling exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Bidirectional-capable unidirectional TVS used with series impedance to limit current into transceiver pins. Use Value: Limits clamped voltage to ≤14.4 V during 8/20 µs surges up to 205 A, preserving transceiver integrity without sacrificing data rate. | Use Scenario: Protecting low-noise analog front-ends of patient-monitoring devices from ESD during handling or cable connection. IC Role / Device Role / Timing Role: Low-capacitance (≤1000 pF) TVS placed across differential sensor inputs to suppress fast transients without distorting mV-level signals. Use Value: Maintains signal fidelity with <1 µA leakage at 85 °C and clamps ESD events to <15 V, meeting IEC 60601-1-2 immunity requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ8.5A (STMicroelectronics) | Same SMB package, but rated for 600 W at 10/1000 µs and 100 W higher clamping voltage (15.0 V @ 38.9 A) | Higher VCL reduces margin for 3.3 V/5 V logic protection but suits 12 V systems with looser voltage tolerances | Select when tighter thermal management is available and slightly higher clamping is acceptable for cost-sensitive designs |
| P6SMB8.5A (ON Semiconductor) | Identical VRM (8.5 V) and VCL (14.4 V), but lower PPP rating (600 W) and higher RD (0.11 Ω) | Marginally reduced surge current handling (40.5 A vs. 41.7 A) and less consistent clamping under repeated stress | Choose for legacy BOM continuity where second-source qualification is required and thermal derating is applied |
Compared with SMBJ8.5A and P6SMB8.5A, SMB6F8.5A offers the lowest dynamic resistance (0.096 Ω) and highest surge current capacity (41.7 A) at its clamping voltage-critical for protecting fast-switching power supplies and high-speed interfaces where voltage overshoot must be minimized.
Availability
SMB6F8.5A is available at Aetrix Electronics and suitable for automotive ECU design, industrial PLC I/O protection, and medical sensor interface applications requiring stable component supply across extended temperature ranges and multi-year production cycles.
Supply support for SMB6F8.5A 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, delivering innovative solutions across automotive, industrial, power, and sensing markets with strong emphasis on reliability and environmental compliance.
The SMB6FxxA series belongs to ST's high-power TVS portfolio, engineered specifically for robust surge immunity in harsh environments-emphasizing low leakage, high-temperature operation, and planar process consistency for mission-critical protection.
FAQ
What is the maximum clamping voltage for SMB6F8.5A under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 14.4 V at 41.7 A for a 10/1000 µs waveform, measured at 25 °C ambient. This value increases with junction temperature at a coefficient of 7.3 × 10⁻⁴/°C, reaching ~15.2 V at Tj = 125 °C per the αT parameter in Table 2.
Can SMB6F8.5A be used in bidirectional signal lines?
No-it is a unidirectional TVS diode intended for DC-biased applications such as power rails or single-ended data lines referenced to ground. For AC or floating signal paths, a bidirectional variant like SMB6F8.5CA or separate back-to-back unidirectional devices are required.
How does the SMB Flat package improve thermal performance compared to standard SMB?
The SMB Flat package reduces thermal resistance (Rth(j-a)) by up to 30% versus standard SMB due to its 1.10 mm height and optimized copper pad layout, achieving ~120 °C/W on a 1 cm² copper area-enabling sustained operation at 175 °C junction temperature without forced cooling.
Is SMB6F8.5A compliant with automotive AEC-Q200 stress testing?
No-while it meets IEC 61000-4-2/4-4 and operates up to 175 °C, SMB6F8.5A is not AEC-Q200 qualified. For automotive-grade surge protection, ST recommends the AEC-Q200-qualified SMAJ8.5A or SMCJ8.5A series, which undergo additional vibration, temperature cycling, and humidity testing.
SMB6F8.5A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-221AA, SMB Flat Leads
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 8.5V
- Voltage - Breakdown (Min):
- 9.4V
- Voltage - Clamping (Max) @ Ipp:
- 14.4V
- Current - Peak Pulse (10/1000µs):
- 41.7A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMBflat
SMB6F8.5A FAQ
1.How can I place an order for SMB6F8.5A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB6F8.5A 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 SMB6F8.5A reliable?
The price and inventory of SMB6F8.5A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMB6F8.5A is usually 5 days.
3.What payment methods are accepted for SMB6F8.5A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB6F8.5A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB6F8.5A?
SMB6F8.5A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB6F8.5A 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 SMB6F8.5A?
For technical support, including SMB6F8.5A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB6F8.5A requirements.
6.How does Aetrix verify that SMB6F8.5A is sourced from the original manufacturer or authorized distributors?
All SMB6F8.5A 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 SMB6F8.5A meets industry standards.
7.What is the process for return or replacement of SMB6F8.5A?
All SMB6F8.5A units undergo pre-shipment inspection (PSI). If there is an issue with SMB6F8.5A, 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 SMB6F8.5A part is unused and in its original packaging.
Return procedure for SMB6F8.5A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB6F8.5A Tags
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