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STMicroelectronics SMB6F20A
- Part No.:
- SMB6F20A
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-221AA, SMB Flat Leads
- Datasheet:
-
SMB6F20A.pdf
- Description:
- TVS DIODE 20VWM 32.4VC SMBFLAT
- Quantity:
- Payment:
- Shipping:
Inventory:2,904
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Product details
Overview
SMB6F20A from STMicroelectronics is a unidirectional 600 W transient voltage suppression (TVS) diode in SMB Flat package, designed to protect sensitive electronics against ESD and surge events. It features a stand-off voltage of 20 V, clamping voltage of 32.4 V at 19.4 A (10/1000 µs), low leakage current (0.2 µA at 25 °C), and operates up to 175 °C junction temperature - ideal for automotive power line and industrial I/O port protection.
For engineers reviewing the SMB6F20A datasheet, SMB6F20A pinout, SMB6F20A application, or SMB6F20A equivalent, key selection criteria include clamping performance under 10/1000 µs surges, thermal stability at elevated Tj, compliance with IEC 61000-4-2 Level 4 (±30 kV contact/air), and footprint compatibility with IPC7531-recommended layout.
Technical Context
This TVS diode uses planar silicon technology to achieve low dynamic resistance (0.402 Ω) and stable breakdown behavior across temperature. Its unidirectional configuration enables asymmetric clamping on DC-biased lines, with VBR min = 22.2 V and max = 24.6 V at 25 °C, and temperature coefficient αT = 9.4 × 10⁻⁴ /°C.
The device meets IEC 61000-4-4 Level 4 (±4 kV) and exceeds IEC 61000-4-2 Level 4 for both contact and air discharge (±30 kV). Its flat 1 mm profile supports high-density PCB layouts while maintaining 470 W peak pulse power capability at Tj = 175 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 20 V - maximum continuous reverse operating voltage before conduction begins |
| Breakdown Voltage (VBR) | 22.2–24.6 V at 1 mA - defines precise clamping onset threshold under DC stress |
| Clamping Voltage (VCL) | 32.4 V at 19.4 A (10/1000 µs) - limits transient-induced overvoltage seen by downstream ICs |
| Peak Pulse Power (PPP) | 600 W (10/1000 µs) - sustains high-energy transients without failure in standard test conditions |
| Leakage Current (IRM) | 0.2 µA at 25 °C - ensures minimal standby power loss and signal integrity in high-impedance circuits |
| Junction Temperature Range | −55 to +175 °C - supports operation in under-hood automotive and industrial environments |
| Dynamic Resistance (RD) | 0.402 Ω - determines voltage rise per ampere during surge, critical for low-clamp design |
Pinout & Package
SMB6F20A is housed in an SMB Flat package (JEDEC MO-136AC), measuring 3.3–3.95 mm × 5.2–5.6 mm × 0.9–1.1 mm height, with matte tin-plated leads compliant with J-STD-002 and MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked side) | Surge return path | Connected to system ground or low-impedance reference; conducts during positive transients on anode |
| Anode | Protected line input | Connected to I/O line or power rail requiring clamping; blocks reverse current until breakdown |
Key Features
| Feature | Design Value |
|---|---|
| Planar silicon construction | Enables tight VBR tolerance and stable leakage across temperature, supporting long-term reliability in harsh environments |
| Flat 1 mm profile | Reduces board space and improves thermal coupling to copper pour, lowering Rth(j-a) to ≤150 °C/W on recommended footprint |
| IEC 61000-4-2 Level 4 compliance | Withstands ±30 kV contact and air discharge - eliminates need for external ESD staging in many industrial interfaces |
| High Tj rating (175 °C) | Permits placement near heat sources (e.g., power MOSFETs, DC-DC converters) without derating concerns |
| Low dynamic resistance (0.402 Ω) | Minimizes clamping voltage overshoot during fast-rising transients, protecting 3.3 V and 5 V logic rails |
Applications
| Automotive Power Line Protection | Industrial Digital I/O Port |
|---|---|
Use Scenario: 12 V battery line in engine control unit exposed to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between power rail and ground, absorbing energy before it reaches LDOs and microcontrollers. Use Value: Clamps to 32.4 V at 19.4 A, preventing damage to 36 V-rated downstream regulators while surviving repeated 10/1000 µs surges. | Use Scenario: RS-485 transceiver interface on factory automation PLC module subject to cable-induced surges. IC Role / Device Role / Timing Role: Bidirectional protection not required; unidirectional SMB6F20A guards the receiver input against positive-going transients on biased lines. Use Value: Low 0.2 µA leakage preserves bus biasing integrity, and 0.402 Ω RD ensures sub-35 V clamping even at 15 A surge peaks. |
| Consumer USB Power Delivery | Smart Meter Communication Interface |
Use Scenario: VBUS line in USB-C PD adapter where ESD robustness must meet IEC 61000-4-2 Level 4 without compromising efficiency. IC Role / Device Role / Timing Role: Primary surge suppressor on 20 V PP output stage, placed upstream of buck converter feedback network. Use Value: 20 V VRM matches nominal PD voltage; 32.4 V clamping prevents latch-up in 3.3 V monitoring ICs during hot-plug events. | Use Scenario: PLC or RF communication port in utility smart meter exposed to lightning-induced surges on outdoor wiring. IC Role / Device Role / Timing Role: First-line transient suppressor on 24 V auxiliary supply rail feeding modem and isolation barrier. Use Value: 470 W peak power at 175 °C allows sustained operation in sealed enclosures; UL94 V0 rating supports safety certification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ20A (Bourns) | Same SMB package, 600 W rating, but higher VBR (22.2–24.5 V) and slightly lower VCL (32.0 V @ 19.4 A); RD = 0.39 Ω | Identical use cases; marginally tighter clamping but identical thermal envelope | Select when sourcing diversity is required and minor VCL variance (<0.4 V) is acceptable |
| P6SMB20A (Littelfuse) | Same SMB footprint and 600 W rating, but higher leakage (1 µA @ 25 °C) and lower Tj max (150 °C) | Not suitable for high-temperature industrial or automotive under-hood use | Prefer only for cost-sensitive consumer applications where ambient Tj stays below 85 °C |
Compared with SMBJ20A and P6SMB20A, SMB6F20A offers superior high-temperature reliability (175 °C vs. 150 °C), lower leakage (0.2 µA vs. 1 µA), and verified IEC 61000-4-2 Level 4 compliance - making it optimal for mission-critical industrial and automotive designs.
Availability
SMB6F20A is available at Aetrix Electronics and suitable for automotive power line protection, industrial digital I/O port hardening, and smart meter communication interface surge suppression requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for SMB6F20A 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 intelligent power, analog, MEMS, and microcontroller solutions for automotive, industrial, and consumer markets.
The SMB6FxxA series belongs to ST's high-reliability TVS portfolio, engineered specifically for robust transient suppression in demanding environments where thermal stability, low leakage, and certified ESD immunity are mandatory.
FAQ
What is the maximum clamping voltage of SMB6F20A under a 10/1000 µs surge?
The maximum clamping voltage (VCL) of SMB6F20A is 32.4 V at 19.4 A under 10/1000 µs waveform, measured at 25 °C ambient. This value increases with junction temperature due to its positive temperature coefficient (αT = 9.4 × 10⁻⁴ /°C), reaching ~34.1 V at Tj = 125 °C using the formula VCL(Tj) = VCL(25 °C) × [1 + αT × (Tj − 25)].
Is SMB6F20A suitable for bidirectional signal line protection?
No - SMB6F20A is a unidirectional TVS diode, intended for DC-biased lines such as power rails or single-ended I/O with defined polarity. For bidirectional protection (e.g., USB D+/D−, RS-232), a symmetric device like SMB6F20CA is required; using SMB6F20A on AC-coupled or floating lines risks forward conduction and improper clamping.
How does SMB6F20A's flat SMB package improve thermal performance?
The SMB Flat package reduces height to 1.1 mm max and optimizes thermal path via extended leadframe exposure. On a 2 cm² copper pour per lead, its Rth(j-a) drops to ~120 °C/W - enabling 470 W surge handling at 175 °C junction temperature. This outperforms standard SMB packages (typically >150 °C/W) and avoids derating in compact, thermally constrained layouts.
Does SMB6F20A require derating for operation above 85 °C ambient?
Yes - while rated for Tj up to 175 °C, ambient temperature rise necessitates thermal design review. At Tamb = 105 °C, maximum allowable power dissipation drops to ~380 W (10/1000 µs) per Figure 3 in DS12898. Designers must verify PCB copper area, airflow, and adjacent heat sources to maintain Tj ≤ 175 °C during surge events.
SMB6F20A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-221AA, SMB Flat Leads
- Series:
- SMB6FxxA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 20V (Max)
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 32.4V
- Current - Peak Pulse (10/1000µs):
- 19.4A
- 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
SMB6F20A FAQ
1.How can I place an order for SMB6F20A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB6F20A 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 SMB6F20A reliable?
The price and inventory of SMB6F20A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMB6F20A is usually 5 days.
3.What payment methods are accepted for SMB6F20A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB6F20A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB6F20A?
SMB6F20A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB6F20A 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 SMB6F20A?
For technical support, including SMB6F20A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB6F20A requirements.
6.How does Aetrix verify that SMB6F20A is sourced from the original manufacturer or authorized distributors?
All SMB6F20A 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 SMB6F20A meets industry standards.
7.What is the process for return or replacement of SMB6F20A?
All SMB6F20A units undergo pre-shipment inspection (PSI). If there is an issue with SMB6F20A, 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 SMB6F20A part is unused and in its original packaging.
Return procedure for SMB6F20A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB6F20A Tags
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