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STMicroelectronics SMA6J8.5A-TR
- Part No.:
- SMA6J8.5A-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMA6J8.5A-TR.pdf
- Description:
- TVS DIODE 8.5VWM 18.7VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:2,307
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Product details
Overview
SMA6J8.5A-TR from STMicroelectronics is a unidirectional 600 W transient voltage suppression diode designed for primary-level ESD and surge protection in DC power rails and signal lines. It features a standoff voltage of 8.5 V, clamping voltage of 13.3 V at 41.7 A (10/1000 μs), and operates up to 175 °C junction temperature-ideal for automotive infotainment power inputs and industrial sensor interfaces.
For engineers reviewing the SMA6J8.5A-TR datasheet, SMA6J8.5A-TR pinout, SMA6J8.5A-TR application, or SMA6J8.5A-TR equivalent, key selection criteria include clamping performance under IEC 61000-4-2 (30 kV contact/air), low leakage (<1 µA at 85 °C), JEDEC DO-214AC (SMA) package compatibility, and thermal robustness for high-reliability embedded systems.
Technical Context
This TVS diode uses planar silicon technology to achieve stable breakdown behavior and low dynamic resistance (0.070 Ω at 25 °C), enabling precise clamping during fast transients. Its unidirectional configuration supports DC-biased circuits where reverse polarity protection is not required.
The device meets IEC 61000-4-4 Level 4 (4 kV) and exceeds IEC 61000-4-2 Level 4 (30 kV air/contact discharge), with validated performance across -55 °C to +175 °C operating junction range and UL94 V0-compliant epoxy encapsulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 8.5 V - Maximum continuous reverse operating voltage before conduction begins |
| Breakdown Voltage (VBR) | 9.4–10.4 V @ 1 mA - Guaranteed avalanche initiation range at 25 °C |
| Clamping Voltage (VCL) | 13.3 V @ 41.7 A (10/1000 μs) - Peak voltage seen by protected circuit during worst-case surge |
| Peak Pulse Power | 600 W (10/1000 μs) - Sustained energy absorption capability per single transient event |
| Leakage Current (IRM) | 1 μA max @ 85 °C - Minimal DC loading on sensitive 3.3 V/5 V supply rails |
| Junction Temperature Range | -55 °C to +175 °C - Enables deployment in under-hood automotive or industrial motor control environments |
| Package | DO-214AC (SMA) - Standardized surface-mount footprint compliant with IPC-7531 and JEDEC registration |
Pinout & Package
DO-214AC (SMA) package: molded epoxy body with matte tin-plated leads, 2.25–2.90 mm width (D), 4.80–5.35 mm length (E), 1.90–2.45 mm height (A1), and 0.75–1.50 mm lead length (L). Complies with J-STD-002, JESD22-B102 E3, and MIL-STD-750 Method 2026 solderability standards.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked band) | Surge current sink | Connected to protected line; conducts transient energy to ground when voltage exceeds VBR |
| Anode | Reference node | Typically tied to system ground or lowest potential rail; completes conduction path during overvoltage events |
Key Features
| Feature | Design Value |
|---|---|
| Low clamping ratio (VCL/VBR ≈ 1.33) | Minimizes stress on downstream ICs by limiting peak voltage to just 33% above breakdown threshold |
| High-temperature reliability (Tj max = 175 °C) | Supports long-term operation in engine control units and industrial PLCs without derating |
| UL94 V0 resin encapsulation | Prevents flame propagation in safety-critical enclosures per international fire-safety requirements |
| JEDEC DO-214AC mechanical standardization | Ensures consistent pick-and-place accuracy and reflow compatibility across automated assembly lines |
Applications
| Automotive Infotainment Power Input | Industrial Sensor Signal Line Protection |
|---|---|
Use Scenario: 12 V battery-fed USB-C port in head unit exposed to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Primary TVS clamp on VBUS rail, absorbing >95% of 600 W surge energy within 1000 μs. Use Value: Prevents damage to USB PD controller ICs by limiting VBUS to ≤13.3 V during transients while maintaining <1 μA leakage at elevated ambient temperatures. | Use Scenario: 4–20 mA current loop interface in factory-floor pressure transmitter subject to ESD from operator handling. IC Role / Device Role / Timing Role: Unidirectional shunt protector on analog input side, triggered only during positive overvoltage events. Use Value: Clamps 30 kV contact discharge to <13.3 V within nanoseconds, preserving 16-bit ADC accuracy without introducing offset drift from leakage. |
| Telecom PoE Midspan Surge Interface | Medical Patient Monitor ECG Lead Port |
Use Scenario: Secondary-side protection on 48 V PoE midspan injector output feeding IEEE 802.3af/at devices. IC Role / Device Role / Timing Role: Standoff-rated TVS on data pair lines, activated only during lightning-induced surges exceeding 8.5 V. Use Value: Maintains signal integrity during normal operation (leakage <0.2 µA at 25 °C) while clamping 4 kV IEC 61000-4-4 bursts to safe levels for Ethernet PHYs. | Use Scenario: Front-end protection for differential ECG electrode inputs exposed to electrostatic discharge in clinical environments. IC Role / Device Role / Timing Role: Low-capacitance unidirectional clamp referenced to patient-isolated ground plane. Use Value: Delivers 30 kV ESD immunity without degrading sub-mV biopotential signal fidelity due to ultra-low leakage and minimal parasitic capacitance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMA6J8.5CA-TR | Bidirectional version; symmetric clamping for AC-coupled or floating lines | Required where reverse-polarity transients or bipolar signals (e.g., RS-485) must be suppressed | Select only if bidirectional protection is needed; otherwise, SMA6J8.5A-TR offers lower leakage and tighter VBR tolerance |
| SMBJ8.5A | Same electrical specs but SMB (DO-214AA) package; 20% larger footprint, higher thermal mass | Preferred where board space allows and higher surge margin (600 W same rating but longer pulse handling) is prioritized | Choose SMBJ8.5A only when PCB layout accommodates larger pad geometry and enhanced thermal dissipation is critical |
Compared with SMA6J8.5CA-TR and SMBJ8.5A, the SMA6J8.5A-TR delivers optimal balance of compact DO-214AC footprint, industry-leading 175 °C junction rating, and lowest leakage among 8.5 V unidirectional TVS diodes-making it ideal for space-constrained, high-temperature DC rail protection.
Availability
SMA6J8.5A-TR is available at Aetrix Electronics and suitable for automotive infotainment power inputs, industrial sensor signal line protection, and telecom PoE midspan surge interfaces requiring stable component supply and full traceability.
Supply support for SMA6J8.5A-TR 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 microcontroller technologies for industrial, automotive, and consumer markets.
The SMA6J series belongs to ST's transient protection product line, engineered specifically for high-reliability DC rail and interface protection in harsh environments where thermal stability, ESD robustness, and long-term leakage performance are mission-critical.
FAQ
What is the maximum clamping voltage of SMA6J8.5A-TR under a 10/1000 μs surge?
The maximum clamping voltage is 13.3 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 V/°C, reaching approximately 14.2 V at Tj = 125 °C per the αT parameter in Table 2.
Does SMA6J8.5A-TR meet automotive qualification standards?
While not AEC-Q200 qualified out-of-the-box, SMA6J8.5A-TR meets core automotive stress requirements: IEC 61000-4-2 (30 kV ESD), IEC 61000-4-4 (4 kV surge), and operates up to 175 °C junction temperature-enabling use in non-safety-critical automotive subsystems like infotainment and body electronics when validated per OEM design guidelines.
How does the DO-214AC (SMA) package compare to DO-214AA (SMB) in thermal performance?
The DO-214AC package has lower thermal resistance than DO-214AA due to shorter lead lengths and optimized copper pad layout per IPC-7531. At identical PCB copper area, SMA6J8.5A-TR achieves ~10–15% lower Rth(j-a) than SMBJ8.5A, improving sustained surge handling in compact layouts-but with reduced absolute power margin due to smaller thermal mass.
Can SMA6J8.5A-TR be used in bidirectional signal paths like RS-485?
No-SMA6J8.5A-TR is unidirectional and conducts only in reverse bias. For RS-485 or other AC-coupled or floating differential lines, the bidirectional SMA6J8.5CA-TR must be used instead, as it provides symmetrical clamping above and below ground reference.
SMA6J8.5A-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AC, SMA
- Series:
- SMA6J, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 8.5V
- Voltage - Breakdown (Min):
- 9.4V
- Voltage - Clamping (Max) @ Ipp:
- 18.7V
- Current - Peak Pulse (10/1000µs):
- 205A (8/20µs)
- 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:
- DO-214AC (SMA)
SMA6J8.5A-TR FAQ
1.How can I place an order for SMA6J8.5A-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA6J8.5A-TR 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 SMA6J8.5A-TR reliable?
The price and inventory of SMA6J8.5A-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA6J8.5A-TR is usually 5 days.
3.What payment methods are accepted for SMA6J8.5A-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA6J8.5A-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA6J8.5A-TR?
SMA6J8.5A-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA6J8.5A-TR 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 SMA6J8.5A-TR?
For technical support, including SMA6J8.5A-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA6J8.5A-TR requirements.
6.How does Aetrix verify that SMA6J8.5A-TR is sourced from the original manufacturer or authorized distributors?
All SMA6J8.5A-TR 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 SMA6J8.5A-TR meets industry standards.
7.What is the process for return or replacement of SMA6J8.5A-TR?
All SMA6J8.5A-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMA6J8.5A-TR, 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 SMA6J8.5A-TR part is unused and in its original packaging.
Return procedure for SMA6J8.5A-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMA6J8.5A-TR Tags
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