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STMicroelectronics SMA6F31A
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- Part No.:
- SMA6F31A
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-221AC, SMA Flat Leads
- Datasheet:
-
SMA6F31A.pdf
- Description:
- TVS DIODE 31VWM 50.2VC SMAFLAT
- Quantity:
- Payment:
- Shipping:
Inventory:2,758
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Product details
Overview
SMA6F31A from STMicroelectronics is a unidirectional 600 W transient voltage suppression (TVS) diode designed for primary surge protection in DC power lines and signal interfaces. It features a 31 V stand-off voltage (VRM), 34.2–37.8 V breakdown voltage (VBR) at 1 mA, 50.2 V clamping voltage (VCL) at 12.3 A peak pulse current (IPP), and operates up to 175 °C junction temperature.
For engineers reviewing the SMA6F31A datasheet, SMA6F31A pinout, SMA6F31A application, or SMA6F31A equivalent, key selection criteria include clamping performance under 10/1000 µs surges, low leakage (<0.2 µA at 25 °C), high-temperature reliability, and compatibility with IPC7531-compliant SMA flat footprint layouts.
Technical Context
The SMA6F31A uses planar silicon avalanche technology to deliver precise, repeatable clamping response during ESD and lightning-induced transients. Its unidirectional configuration enables integration into polarity-sensitive DC rails without reverse-bias conduction concerns.
It meets IEC 61000-4-2 Level 4 (±25 kV contact / ±30 kV air discharge) and supports robust thermal management via low dynamic resistance (0.45 Ω) and JEDEC-registered SMA package with 260 °C soldering tolerance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 31 V - Maximum continuous reverse operating voltage before leakage exceeds 0.2 µA |
| Breakdown Voltage (VBR) | 34.2–37.8 V at 1 mA - Ensures reliable triggering above normal rail voltage with margin |
| Clamping Voltage (VCL) | 50.2 V at 12.3 A (10/1000 µs) - Limits downstream voltage stress during surge events |
| Peak Pulse Power | 600 W (10/1000 µs), 4 kW (8/20 µs) - Supports industrial-grade surge immunity per IEC 61000-4-5 |
| Leakage Current | 0.2 µA at 25 °C, 1 µA at 85 °C - Minimizes standby power loss in battery-backed systems |
| Junction Temperature Range | −55 °C to +175 °C - Enables deployment in under-hood automotive or high-ambient industrial environments |
| Dynamic Resistance | 0.45 Ω - Low impedance ensures fast, stable clamping with minimal voltage overshoot |
Pinout & Package
The SMA6F31A is housed in an industry-standard SMA (DO-214AC) flat package with two terminals: Cathode (marked band) and Anode. The package complies with IPC7531 footprint guidelines and JEDEC MO-136AB outline.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Surge current sink | Connected to protected line; conducts transient energy to ground when VBR exceeded |
| Anode | Reference node | Tied to system ground or lower-potential rail; completes clamping path during overvoltage |
Key Features
| Feature | Design Value |
|---|---|
| High-temperature operation | Rated for continuous use up to 175 °C junction temperature - eliminates derating in thermally constrained enclosures |
| Low-leakage planar construction | 0.2 µA max IR at VRM and 25 °C - preserves signal integrity and battery life in always-on circuits |
| IEC 61000-4-2 Level 4 compliance | Withstands ±25 kV contact / ±30 kV air ESD - satisfies stringent EMC requirements for industrial HMI and telecom ports |
| Matte tin lead finish | RoHS-compliant, whisker-resistant plating per JESD201 Class 2 - ensures long-term solder joint reliability |
| Standardized SMA footprint | IPC7531 and JEDEC MO-136AB registered - enables drop-in replacement and automated assembly compatibility |
Applications
| Industrial PLC I/O Protection | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: 24 V DC input channels on programmable logic controller backplanes exposed to inductive switching noise and cable discharge events. IC Role / Device Role / Timing Role: Primary unidirectional TVS clamp placed directly at connector entry point to limit transient voltage to <50.2 V. Use Value: Prevents damage to upstream RS-485 transceivers and microcontroller GPIOs during 1 kV/500 A surge tests per IEC 61000-4-4. | Use Scenario: LIN bus and sensor supply lines in body control modules subject to load dump and jump-start transients. IC Role / Device Role / Timing Role: Standoff-rated surge protector on 12 V battery-fed sub-circuits, operating continuously at 85–125 °C ambient. Use Value: Maintains <1 µA leakage at 85 °C to avoid parasitic drain while clamping 8/20 µs spikes to ≤65 V per ISO 7637-2 Pulse 1/2a. |
| Telecom Power Feeds | Smart Meter AC/DC Auxiliary Supply |
Use Scenario: -48 V DC power input stage of remote radio units and base station controllers. IC Role / Device Role / Timing Role: First-line defense against lightning-induced surges coupled onto telecom distribution lines. Use Value: Delivers 4 kW peak pulse handling (8/20 µs) with 0.45 Ω dynamic resistance to minimize let-through energy during multi-kA events. | Use Scenario: Secondary-side 5–12 V DC output of isolated flyback converters powering metrology ICs and RF modules. IC Role / Device Role / Timing Role: Low-capacitance, low-leakage TVS protecting precision analog inputs and crystal oscillator circuits. Use Value: Clamps ESD events to <50.2 V without distorting 1 kHz–1 MHz metering signals due to <1 nF junction capacitance at 0 V bias. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33A | 33 V VRM, 53.3 V VCL at 11.8 A, 400 W (10/1000 µs) | Lower power rating and higher clamping voltage - suitable only for lighter-duty surge environments | Select when cost sensitivity outweighs need for 600 W surge margin and tighter clamping |
| SMCJ33A | Same VRM (33 V), but SMC package (DO-214AB); 1500 W (10/1000 µs) | Larger footprint and higher thermal mass - better for sustained surge duty but incompatible with SMA-restricted PCB space | Choose for higher-power applications where board area allows larger package and enhanced thermal dissipation |
Compared with SMAJ33A and SMCJ33A, the SMA6F31A uniquely balances 600 W surge capability, 50.2 V clamping at 12.3 A, and compact SMA footprint-making it optimal for space-constrained 24–32 V DC systems requiring both high immunity and low leakage.
Availability
SMA6F31A is available at Aetrix Electronics and suitable for industrial PLC I/O protection, automotive BCM power rails, and telecom power feed applications requiring stable component supply across extended temperature and surge stress conditions.
Supply support for SMA6F31A 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.
The SMA6F Transil series targets high-reliability transient suppression in harsh-environment electronics, emphasizing low leakage, high-temperature stability, and standardized surface-mount packaging for automated manufacturing.
FAQ
What is the maximum clamping voltage of SMA6F31A under a 10/1000 µs surge?
The SMA6F31A clamps to 50.2 V at 12.3 A peak pulse current under a 10/1000 µs waveform, as specified in Table 2 of DS12564 Rev 3. This value is measured at Tamb = 25 °C and defines the upper voltage limit imposed on protected circuitry during standardized surge testing.
Does SMA6F31A meet automotive qualification standards?
The SMA6F31A is not AEC-Q200 qualified, but its −55 °C to +175 °C operating junction temperature range, IEC 61000-4-2 Level 4 ESD rating, and robust thermal design make it widely deployed in non-safety-critical automotive subsystems such as body control modules and infotainment power supplies.
Can SMA6F31A be used in bidirectional configurations?
No - SMA6F31A is a unidirectional TVS diode, intended only for polarity-defined DC lines. For bidirectional protection (e.g., AC signal lines or USB data pairs), ST offers the SMA6F31CA variant, which provides symmetrical clamping in both directions with identical VBR and VCL specifications.
What is the recommended PCB footprint for SMA6F31A?
The SMA6F31A requires the IPC7531-compliant SMA (DO-214AC) footprint, with pad dimensions matching Figure 13 in DS12564 Rev 3: 2.9 mm × 1.6 mm pads, 4.0 mm center-to-center spacing, and 3.5 mm overall length. Copper pour under leads improves thermal dissipation and reduces Zth(j-a) by up to 50%.
SMA6F31A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-221AC, SMA Flat Leads
- Series:
- SMA6F, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 31V
- Voltage - Breakdown (Min):
- 34.2V
- Voltage - Clamping (Max) @ Ipp:
- 50.2V
- Current - Peak Pulse (10/1000µs):
- 12.3A
- 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:
- SMAflat
SMA6F31A FAQ
1.How can I place an order for SMA6F31A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA6F31A 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 SMA6F31A reliable?
The price and inventory of SMA6F31A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA6F31A is usually 5 days.
3.What payment methods are accepted for SMA6F31A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA6F31A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA6F31A?
SMA6F31A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA6F31A 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 SMA6F31A?
For technical support, including SMA6F31A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA6F31A requirements.
6.How does Aetrix verify that SMA6F31A is sourced from the original manufacturer or authorized distributors?
All SMA6F31A 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 SMA6F31A meets industry standards.
7.What is the process for return or replacement of SMA6F31A?
All SMA6F31A units undergo pre-shipment inspection (PSI). If there is an issue with SMA6F31A, 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 SMA6F31A part is unused and in its original packaging.
Return procedure for SMA6F31A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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