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STMicroelectronics SMA6J85A-TR
- Part No.:
- SMA6J85A-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMA6J85A-TR.pdf
- Description:
- TVS DIODE 85VWM 146VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:4,685
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Product details
Overview
SMA6J85A-TR from STMicroelectronics is a unidirectional 600 W transient voltage suppression (TVS) diode designed for primary-level ESD and surge protection in DC power rails and signal lines. It features a standoff voltage (VRM) of 85 V, clamping voltage (VCL) of 134 V at 4.6 A (10/1000 µs), and operates up to 175 °C junction temperature - enabling robust protection in automotive body electronics, industrial PLC I/O modules, and telecom power supplies.
For engineers reviewing the SMA6J85A-TR datasheet, SMA6J85A-TR pinout, SMA6J85A-TR application, or SMA6J85A-TR equivalent, key selection criteria include its 85 V reverse standoff rating, low leakage (<0.2 µA @ 25 °C), JEDEC DO-214AC (SMA) package compatibility, and IEC 61000-4-2 ±30 kV contact/air discharge compliance - all critical for high-reliability overvoltage hardening.
Technical Context
This TVS diode uses planar silicon technology to achieve low dynamic resistance (RD = 3.29 Ω at 8/20 µs) and stable clamping performance across temperature. Its unidirectional configuration provides asymmetric conduction - forward-biased during normal operation and reverse-biased clamping during transients - making it suitable for DC-biased lines where polarity is fixed.
The device meets IEC 61000-4-4 Level 4 (4 kV) surge immunity and exceeds IEC 61000-4-2 Level 4 ESD requirements. Its thermal design supports continuous operation at Tj = 175 °C, with solderable matte tin leads qualified per JESD 22-B102 E3 and MIL-STD-750 Method 2026.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 85 V - maximum continuous reverse operating voltage before breakdown; sets protection threshold for 72–90 V DC systems. |
| Clamping Voltage (VCL) | 134 V @ 4.6 A (10/1000 µs) - peak voltage seen by protected circuit during worst-case surge; limits stress on downstream components. |
| Peak Pulse Power (PPP) | 600 W (10/1000 µs) - energy-handling capability for long-duration surges like lightning-induced transients in industrial wiring. |
| Leakage Current (IRM) | 0.2 µA @ 25 °C - negligible standby current draw; avoids battery drain or signal integrity issues in low-power sensor interfaces. |
| Junction Temperature Range | −55 to +175 °C - enables deployment in under-hood automotive, motor drive control, and high-ambient industrial environments. |
| ESD Rating | ±30 kV (IEC 61000-4-2, contact & air) - exceeds Level 4 requirement; protects against human-body-model discharges in assembly and field use. |
| Dynamic Resistance (RD) | 3.29 Ω @ 8/20 µs - determines clamping voltage rise under fast transients; lower RD improves protection margin for sub-microsecond events. |
Pinout & Package
Package: DO-214AC (SMA), JEDEC-registered surface-mount outline with epoxy resin meeting UL94 V0 flammability rating. Dimensions: D = 2.25–2.90 mm, E = 4.80–5.35 mm, L = 0.75–1.50 mm. Recommended IPC-7531 footprint provided.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked band) | Surge current sink terminal | Connected to protected line; conducts transient energy to ground when reverse voltage exceeds VRM. |
| Anode | Reference/ground return path | Typically tied to system ground plane; completes low-inductance surge current loop for effective clamping. |
Key Features
| Feature | Design Value |
|---|---|
| Planar silicon construction | Enables low leakage (<0.2 µA @ 25 °C) and stable VBR drift over temperature - critical for precision analog front-ends. |
| High-temperature operation (Tj max = 175 °C) | Supports placement near heat sources (e.g., power MOSFETs, transformers) without derating - reduces need for thermal spacing. |
| UL94 V0 resin encapsulation | Meets flame-retardant safety standards for industrial and automotive end equipment requiring certified material compliance. |
| Matte tin-plated leads | Ensures reliable solder wetting and intermetallic formation per J-STD-002; eliminates whisker risk per JESD-201 Class 2. |
| IEC 61000-4-4 Level 4 compliance | Validated for 4 kV surge immunity - sufficient for AC mains-connected peripherals and industrial fieldbus nodes. |
Applications
| Automotive Body Control Module | Industrial PLC Digital Input |
|---|---|
Use Scenario: Protecting LIN bus transceivers and microcontroller GPIOs from load dump and alternator ripple in vehicle door modules. IC Role / Device Role / Timing Role: Primary overvoltage clamp on 12 V supply rail and bidirectional data lines - absorbs transients before they reach sensitive logic. Use Value: Prevents latch-up and permanent damage during ISO 7637-2 Pulse 5a (load dump) events up to 60 V peak, leveraging 85 V VRM headroom. |
Use Scenario: Shielding 24 V DC digital input circuits from inductive kickback caused by relay/solenoid switching in factory automation cabinets. IC Role / Device Role / Timing Role: Fast-response shunt protector placed directly at connector entry point - clamps spikes within nanoseconds to preserve optocoupler integrity. Use Value: Maintains functional safety by limiting transient voltage to ≤134 V, well below the 150 V isolation rating of common 24 V input optocouplers. |
| Telecom Power Supply Input | Smart Meter Communication Interface |
Use Scenario: Safeguarding AC/DC converter primary-side rectifier outputs against lightning-induced surges entering via outdoor cabling in DSLAM or base station power units. IC Role / Device Role / Timing Role: Secondary-stage TVS after MOV-based coarse protection - handles residual fast-rising edges that bypass bulk clamping. Use Value: Delivers 600 W (10/1000 µs) pulse handling without degradation, ensuring long-term reliability in harsh outdoor deployments. |
Use Scenario: Protecting RS-485 transceivers in utility smart meters from ESD events during field installation or maintenance in humid, dusty environments. IC Role / Device Role / Timing Role: Point-of-entry ESD suppressor on differential bus lines - clamps ±30 kV HBM discharges before transceiver inputs. Use Value: Eliminates need for external series resistors or ferrites by providing full IEC 61000-4-2 Level 4 compliance in a single discrete component. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMA6J85CA-TR | Bidirectional version; symmetric clamping (VCL = 134 V in both polarities); higher capacitance (~100 pF @ 1 V). | Required for AC-coupled or floating signal lines (e.g., Ethernet PHY, USB D+/D−) where polarity reversal occurs. | Select only if bidirectional protection is mandated; otherwise, unidirectional SMA6J85A-TR offers lower leakage and better DC rail efficiency. |
| SMBJ85A | Same VRM/VCL specs but in larger SMB (DO-214AA) package; 600 W rating, higher thermal mass, 1.5× footprint area. | Better suited for high-volume thermal cycling environments or where PCB space allows larger pads for improved heat dissipation. | Choose SMBJ85A only when board layout permits larger footprint and enhanced thermal margin is prioritized over miniaturization. |
Compared with SMA6J85CA-TR and SMBJ85A, SMA6J85A-TR delivers optimal balance of compact DO-214AC packaging, ultra-low leakage, and proven 175 °C operation - making it preferred for space-constrained, high-temperature DC rail protection where polarity is fixed.
Availability
SMA6J85A-TR is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC I/O modules, telecom power supplies, and smart meter communication interfaces requiring stable component supply and long-term manufacturability.
Supply support for SMA6J85A-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 automotive, industrial, and power management solutions with broad IP and manufacturing scale.
SMA6JxxA belongs to ST's high-reliability TVS diode product line, engineered specifically for robust electrostatic and surge protection in harsh-environment electronics - emphasizing thermal stability, low leakage, and international compliance.
FAQ
What is the maximum clamping voltage of SMA6J85A-TR under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 134 V at a peak pulse current (IPP) of 4.6 A for a 10/1000 µs waveform, as specified in Table 2 of DS5142 Rev 11. This value is measured at Tamb = 25 °C and represents the upper limit of voltage imposed on the protected circuit during standardized surge testing.
Can SMA6J85A-TR be used in bidirectional signal lines?
No - SMA6J85A-TR is unidirectional and conducts only in reverse bias during overvoltage events. For bidirectional protection (e.g., RS-485, CAN, or AC-coupled lines), the SMA6J85CA-TR variant must be used, as it provides symmetrical clamping in both polarities per its datasheet specifications.
What is the recommended PCB footprint for SMA6J85A-TR?
The manufacturer specifies an IPC-7531-compliant SMA footprint: pad length 5.43 mm (2.63 mm center-to-center), pad width 1.40 mm, and spacing 1.64 mm between inner edges. This matches JEDEC DO-214AC mechanical dimensions and ensures optimal thermal and mechanical reliability during reflow soldering.
Does SMA6J85A-TR meet automotive qualification standards?
While not AEC-Q200 qualified out-of-box, SMA6J85A-TR meets key automotive-relevant requirements: 175 °C operating junction temperature, ±30 kV ESD immunity (IEC 61000-4-2), and robust surge handling per IEC 61000-4-4. Customers may qualify it for specific automotive applications per internal stress-test protocols.
SMA6J85A-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):
- 85V
- Voltage - Breakdown (Min):
- 94V
- Voltage - Clamping (Max) @ Ipp:
- 146V
- Current - Peak Pulse (10/1000µs):
- 22.5A (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)
SMA6J85A-TR FAQ
1.How can I place an order for SMA6J85A-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA6J85A-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 SMA6J85A-TR reliable?
The price and inventory of SMA6J85A-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA6J85A-TR is usually 5 days.
3.What payment methods are accepted for SMA6J85A-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA6J85A-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA6J85A-TR?
SMA6J85A-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA6J85A-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 SMA6J85A-TR?
For technical support, including SMA6J85A-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA6J85A-TR requirements.
6.How does Aetrix verify that SMA6J85A-TR is sourced from the original manufacturer or authorized distributors?
All SMA6J85A-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 SMA6J85A-TR meets industry standards.
7.What is the process for return or replacement of SMA6J85A-TR?
All SMA6J85A-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMA6J85A-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 SMA6J85A-TR part is unused and in its original packaging.
Return procedure for SMA6J85A-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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