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STMicroelectronics SMA6F85A
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- Part No.:
- SMA6F85A
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-221AC, SMA Flat Leads
- Datasheet:
-
SMA6F85A.pdf
- Description:
- TVS DIODE 85VWM 137VC SMAFLAT
- Quantity:
- Payment:
- Shipping:
Inventory:6,714
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Product details
Overview
SMA6F85A from STMicroelectronics is a unidirectional 600 W transient voltage suppression (TVS) diode designed for primary-level surge protection in DC power rails and signal lines. It features a 85 V stand-off voltage (VRM), 100 V typical breakdown voltage (VBR) at 1 mA, clamps to 137 V at 4.6 A (10/1000 µs), and operates up to 175 °C junction temperature - deployed in industrial power supplies and automotive body control modules.
For engineers reviewing the SMA6F85A datasheet, SMA6F85A pinout, SMA6F85A application, or SMA6F85A equivalent, key selection criteria include clamping voltage under 10/1000 µs surge, leakage current ≤1 µA at 85 °C, unidirectional polarity, IEC 61000-4-2 Level 4 ESD robustness (±25 kV contact), and SMA flat package thermal performance on FR4 PCBs.
Technical Context
The SMA6F85A uses planar silicon avalanche technology to deliver precise voltage clamping during fast transients. Its dynamic resistance of 3.29 Ω (at 25 °C, 10/1000 µs) ensures predictable VCL rise with increasing IPP, while its αT voltage temperature coefficient of 10.6 × 10⁻⁴ /°C enables accurate VBR and VCL derating across –55 °C to +175 °C operation.
It complies with IEC 61000-4-2 (150 pF/330 Ω), exceeding Level 4 ESD immunity, and supports high-reliability mounting via JEDEC-standard SMA flat package with matte tin lead finish - qualified per J-STD-020 MSL Level 1 and JESD 22-B102 E3.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 85 V - maximum continuous reverse operating voltage before leakage exceeds 1 µA at 85 °C |
| Breakdown Voltage (VBR) | 95–105 V at 1 mA - defines onset of avalanche conduction; tight 10 V window ensures consistent turn-on |
| Clamping Voltage (VCL) | 137 V at 4.6 A (10/1000 µs) - limits downstream circuit stress during 600 W surge events |
| Peak Pulse Power (PPP) | 600 W (10/1000 µs) - sustains 600 W surge for 1 ms at 25 °C; derates to 400 W at Tj = 175 °C |
| Leakage Current (IRM) | 0.2 µA at 25 °C, 1 µA at 85 °C - enables low-power standby circuits without parasitic drain |
| Junction Temperature Range | –55 °C to +175 °C - supports under-hood automotive and industrial environments without derating |
| ESD Rating | ±25 kV contact, ±30 kV air (IEC 61000-4-2) - exceeds Level 4 for robust system-level ESD immunity |
Pinout & Package
The SMA6F85A is housed in an industry-standard SMA (DO-214AC) flat package with two terminals: Cathode (marked band) and Anode. The package measures 4.60 mm × 2.90 mm × 2.25 mm (L × W × H), with 3.95–4.60 mm body width (E1), 2.25–2.90 mm length (D), and 0.75–1.20 mm lead length (L).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Surge current sink | Connected to protected line; conducts avalanche current to ground during overvoltage |
| Anode | Reference node | Typically tied to system ground or lower-potential rail; completes clamping path |
Key Features
| Feature | Design Value |
|---|---|
| High-temperature reliability | Rated for continuous operation up to 175 °C junction temperature - eliminates thermal derating in enclosed enclosures |
| Low-leakage planar construction | 0.2 µA max IRM at 25 °C - preserves battery life in always-on IoT sensors and automotive wake-up circuits |
| Precision clamping stability | VBR tolerance ±5% (95–105 V) and αT = 10.6 × 10⁻⁴ /°C - enables accurate system-level surge margin calculation |
| Industry-standard footprint | JEDEC DO-214AC (SMA) outline with IPC-7531-compliant pad layout - drop-in replacement for legacy TVS diodes |
| ESD-hardened packaging | Matte tin-plated leads, JESD-201 Class 2 whisker resistance, and MSL Level 1 - ensures long-term solder joint integrity |
Applications
| Industrial PLC I/O Protection | Automotive Body Control Module |
|---|---|
Use Scenario: 24 V DC input channels on programmable logic controller backplanes exposed to inductive switching surges from solenoids and relays. IC Role / Device Role / Timing Role: Primary unidirectional TVS clamp placed upstream of input conditioning circuitry and isolation ICs. Use Value: Clamps 600 W transients to ≤137 V within 1 ns, preventing damage to 30 V-rated op-amps and digital isolators without adding series impedance. | Use Scenario: LIN bus and switched 12 V supply lines in door module ECUs subject to load dump and ISO 7637-2 pulse 1/2a. IC Role / Device Role / Timing Role: Standoff-rated TVS on power rail and data line, coordinated with ceramic capacitor filtering. Use Value: Withstands 175 °C ambient under hood, maintains <1 µA leakage at elevated temperature, and suppresses >25 kV ESD without latch-up. |
| Telecom Power Feeds | Smart Meter DC Power Rails |
Use Scenario: -48 V DC telecom power distribution boards where lightning-induced surges propagate from outdoor plant wiring. IC Role / Device Role / Timing Role: First-stage surge protector before DC-DC converters and PMICs. Use Value: Delivers 600 W peak power handling at 85 V VRM, enabling compact board layout with minimal trace inductance impact on clamping response. | Use Scenario: Battery-backed 3.3 V and 5 V rails in utility smart meters installed in thermally uncontrolled outdoor enclosures. IC Role / Device Role / Timing Role: Low-leakage TVS on microcontroller VDD and RTC backup lines. Use Value: 0.2 µA leakage at 25 °C prevents measurable battery drain over 10-year field life; 175 °C rating avoids thermal shutdown during summer ambient peaks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ85A (Littelfuse) | Same VRM (85 V), but higher VCL = 139 V @ 4.3 A (10/1000 µs); 500 W PPP rating | Limited to lower-energy surges; less margin for 600 W compliance-critical designs | Select when cost sensitivity outweighs 100 W power headroom requirement |
| 1.5SMC85A (ON Semiconductor) | Same VRM and VCL (137 V @ 4.6 A), but SMC (DO-214AB) package - 1.5× larger footprint | Requires PCB redesign; better thermal dissipation only if copper area exceeds 3 cm² | Choose only if existing SMC land pattern must be reused and thermal budget allows |
Compared with SMAJ85A and 1.5SMC85A, the SMA6F85A delivers superior 600 W surge capability in the smallest standard footprint (SMA), tighter VBR tolerance, and verified 175 °C operation - making it optimal for space-constrained, high-temperature industrial and automotive power rail protection.
Availability
SMA6F85A is available at Aetrix Electronics and suitable for industrial PLC I/O protection, automotive body control modules, telecom power feeds, and smart meter DC power rails requiring stable component supply across extended temperature and surge stress conditions.
Supply support for SMA6F85A 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, specializing in power management, analog, MEMS, and microcontrollers for industrial, automotive, and consumer markets.
The SMA6F Transil series targets high-reliability transient suppression in harsh environments, emphasizing low leakage, high junction temperature resilience, and IEC/ISO-compliant surge robustness for mission-critical power and signal lines.
FAQ
What is the maximum clamping voltage of SMA6F85A under a 10/1000 µs surge?
The SMA6F85A clamps to 137 V at 4.6 A under a 10/1000 µs waveform, as specified in Table 2 of DS12564 Rev 3. This value is measured at Tamb = 25 °C and represents the upper limit of voltage seen by downstream components during a standardized 600 W surge event.
Does SMA6F85A meet automotive AEC-Q200 requirements?
No - SMA6F85A is not AEC-Q200 qualified. While it operates up to 175 °C and meets IEC 61000-4-2 ESD requirements, ST does not list it in their AEC-Q200 stress-tested product portfolio. For automotive-grade TVS, consider ST's Automotive Transil series such as SMA6QxxA.
Can SMA6F85A be used in bidirectional configurations?
No - SMA6F85A is unidirectional only, as confirmed by its "A" suffix in the ordering code and electrical characterization (Figure 1 shows VBR/VCL defined for reverse bias only). For bidirectional protection, ST offers the SMA6F85CA variant with symmetrical clamping.
What is the recommended PCB footprint for SMA6F85A?
The recommended footprint follows IPC-7531 and JEDEC DO-214AC standards: 4.6 mm pad width (E1), 2.9 mm pad length (D), 1.2 mm pad spacing (G1), and 0.8 mm solder mask opening per lead. Figure 13 in DS12564 Rev 3 provides exact dimensions in mm and inches for FR4 boards with 35 µm copper.
SMA6F85A 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):
- 85V (Max)
- Voltage - Breakdown (Min):
- 95V
- Voltage - Clamping (Max) @ Ipp:
- 137V
- Current - Peak Pulse (10/1000µs):
- 4.6A
- 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
SMA6F85A FAQ
1.How can I place an order for SMA6F85A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA6F85A 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 SMA6F85A reliable?
The price and inventory of SMA6F85A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA6F85A is usually 5 days.
3.What payment methods are accepted for SMA6F85A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA6F85A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA6F85A?
SMA6F85A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA6F85A 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 SMA6F85A?
For technical support, including SMA6F85A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA6F85A requirements.
6.How does Aetrix verify that SMA6F85A is sourced from the original manufacturer or authorized distributors?
All SMA6F85A 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 SMA6F85A meets industry standards.
7.What is the process for return or replacement of SMA6F85A?
All SMA6F85A units undergo pre-shipment inspection (PSI). If there is an issue with SMA6F85A, 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 SMA6F85A part is unused and in its original packaging.
Return procedure for SMA6F85A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMA6F85A Tags
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