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STMicroelectronics SMBJ8.5CA-TR
- Part No.:
- SMBJ8.5CA-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ8.5CA-TR.pdf
- Description:
- TVS DIODE 8.5VWM 19.5VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:509
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Product details
Overview
SMBJ8.5CA-TR from STMicroelectronics is a bidirectional transient voltage suppression (TVS) diode in SMB package, designed for IEC 61000-4-2 ESD and IEC 61000-4-4 surge protection of signal/power lines. It features 8.5 V stand-off voltage (VRM), 14.4 V clamping voltage (VCL) at 41.7 A peak pulse current (IPP), 600 W peak pulse power (10/1000 µs), and operates up to 150 °C junction temperature - deployed in industrial power supplies and automotive body control modules.
For engineers reviewing the SMBJ8.5CA-TR datasheet, SMBJ8.5CA-TR pinout, SMBJ8.5CA-TR application, or SMBJ8.5CA-TR equivalent, key selection criteria include bidirectional clamping symmetry, low leakage (<1 µA at 85 °C), UL497B recognition for isolated loop circuits, and compliance with IEC 61000-4-2 level 4 (30 kV contact/air discharge).
Technical Context
This bidirectional TVS diode uses planar silicon junction technology to achieve symmetrical reverse/forward clamping behavior, enabling robust protection against both polarity transients without external polarity management. Its dynamic resistance (RD = 0.096 Ω at 10/1000 µs) ensures minimal voltage overshoot during fast-rising surges.
Designed for high-reliability SMPS and industrial interfaces, it maintains stable clamping performance across -55 °C to +150 °C operating junction range and supports reflow soldering per J-STD-020 MSL level 1. The device meets UL497B (file E136224) for isolated loop circuit protection and exceeds IEC 61000-4-2 level 4 ESD immunity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 8.5 V - Maximum continuous reverse working voltage before clamping initiates. |
| Clamping Voltage (VCL) | 14.4 V at 41.7 A (10/1000 µs) - Peak voltage seen by protected circuit during worst-case surge. |
| Peak Pulse Power (PPP) | 600 W (10/1000 µs) - Sustained surge energy handling capability at 25 °C ambient. |
| Leakage Current (IRM) | 1 µA max at 85 °C - Ensures minimal standby power loss and signal integrity in high-impedance circuits. |
| Junction Temperature (Tj) | -55 °C to +150 °C - Enables deployment in under-hood automotive and industrial environments. |
| ESD Rating | 30 kV contact & air discharge (IEC 61000-4-2 level 4) - Protects against human-body-model and system-level ESD events. |
| UL Recognition | UL497B, file E136224 - Certified for use as isolated loop circuit protector in safety-critical systems. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, matte tin-plated leads, JEDEC-registered outline, IPC7531-compliant footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Anode for reverse polarity) | Transient current sink path | Bidirectional conduction allows clamping in both directions; no polarity marking required on PCB layout. |
| Anode (Cathode for reverse polarity) | Transient current sink path | Identical electrical role to Cathode terminal due to symmetric internal structure; terminals are interchangeable in layout. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping symmetry | Equal VBR (min 9.4 V) and VCL (14.4 V) in both polarities - eliminates need for polarity-aware placement or external diodes. |
| Low dynamic resistance | 0.096 Ω at 10/1000 µs - reduces clamping voltage overshoot and improves protection margin for sensitive ICs. |
| High-temperature reliability | Rated for 150 °C Tj with <1 µA leakage at 85 °C - supports compact thermal design in sealed enclosures or near heat sources. |
| UL497B certification | Recognized as isolated loop circuit protector (E136224) - satisfies safety requirements for telecom, building automation, and industrial fieldbus interfaces. |
| ESD robustness | 30 kV contact/air discharge per IEC 61000-4-2 - protects RS-485, CAN, USB, and sensor interfaces without additional shielding. |
Applications
| Industrial Power Supply Input Protection | Automotive Body Control Module (BCM) Signal Lines |
|---|---|
Use Scenario: 24 V DC input stage of DIN-rail mounted PLC power supply exposed to load dump and inductive switching transients. IC Role / Device Role / Timing Role: Bidirectional TVS clamp limiting surge voltage to ≤14.4 V during 41.7 A 10/1000 µs transients. Use Value: Prevents damage to upstream rectifier diodes and downstream DC-DC controller ICs while maintaining UL497B compliance for isolated secondary-side circuits. |
Use Scenario: LIN bus and door module sensor inputs subject to ESD events and battery reverse-connection transients. IC Role / Device Role / Timing Role: Fast-response (sub-nanosecond) voltage clamp protecting MCU GPIOs and analog front-end amplifiers. Use Value: Maintains signal integrity under 30 kV ESD stress and suppresses 8/20 µs surges up to 205 A without latch-up or parametric shift. |
| RS-485 Transceiver Port Protection | Smart Meter Communication Interface |
Use Scenario: Half-duplex RS-485 node in utility substation environment with lightning-induced common-mode surges. IC Role / Device Role / Timing Role: Common-mode TVS pair (A/B lines to GND) limiting differential and common-mode overvoltage simultaneously. Use Value: Clamps 10/1000 µs surges to <14.4 V while preserving data integrity up to 10 Mbps due to low junction capacitance (<100 pF at 0 V). |
Use Scenario: HAN (Home Area Network) interface in electricity meter exposed to ESD during field installation and conducted surges via PLC coupling. IC Role / Device Role / Timing Role: Primary-level transient suppressor on M-Bus or RF module supply rails prior to LDO regulation. Use Value: Enables compliance with EN 61000-4-2/4-4/4-5 while supporting extended product lifetime (>15 years) via low leakage and high Tj stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ8.5CA from Vishay (SM8S8.5CA) | Higher clamping voltage (15.0 V @ 40 A), lower IPP (40 A), same VRM and package. | Marginally reduced protection level for 3.3 V logic interfaces; suitable where higher VCL is acceptable. | Select when prioritizing cost over clamping tightness and system-level testing confirms 15.0 V VCL is within safe operating area. |
| P6SMB8.5CA from ON Semiconductor | Identical VRM (8.5 V), slightly higher VCL (14.5 V @ 41.2 A), same SMB package and UL497B recognition. | Negligible performance difference; validated in same automotive EMC test suites per ISO 16750-2. | Preferred for dual-sourcing programs requiring second-source qualification with identical footprint and test report alignment. |
Compared with SMBJ8.5CA-TR, SM8S8.5CA trades tighter clamping for broader surge current tolerance, while P6SMB8.5CA offers drop-in compatibility with minor VCL variance - all three meet IEC 61000-4-2 level 4 and UL497B, but only ST's version specifies 0.096 Ω RD for lowest overshoot.
Availability
SMBJ8.5CA-TR is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, RS-485 transceiver ports, and smart meter communication interfaces requiring stable component supply and long-term lifecycle support.
Supply support for SMBJ8.5CA-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, delivering intelligent power, sensing, and control solutions for automotive, industrial, and consumer markets.
The SMBJ series belongs to ST's high-reliability TVS portfolio, engineered specifically for robust transient suppression in harsh electromagnetic environments - emphasizing low leakage, high Tj operation, and regulatory compliance for industrial and automotive safety-critical systems.
FAQ
What is the maximum clamping voltage of SMBJ8.5CA-TR under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 14.4 V at 41.7 A peak pulse current for a 10/1000 µs waveform, measured at 25 °C ambient. This value increases with junction temperature per αT = 7.3 × 10⁻⁴/°C, reaching ~15.1 V at 125 °C Tj.
Does SMBJ8.5CA-TR require polarity-specific PCB layout?
No - SMBJ8.5CA-TR is a bidirectional TVS diode with symmetrical clamping characteristics in both polarities. Its two terminals are electrically identical; orientation on PCB does not affect functionality, simplifying layout and assembly.
How does SMBJ8.5CA-TR differ from unidirectional SMBJ8.5A-TR?
SMBJ8.5CA-TR provides equal clamping in both directions (±8.5 V VRM), while SMBJ8.5A-TR clamps only in reverse bias (8.5 V VRM, forward conduction at ~1.2 V). CA versions are used where transients may occur with either polarity, such as AC-coupled data lines or floating grounds.
Is SMBJ8.5CA-TR compliant with lead-free reflow standards?
Yes - it is qualified for lead-free reflow per J-STD-020 MSL level 1, with peak temperature up to 245 °C for ≤30 seconds. The matte tin-plated leads meet JESD 22-B102 E3 and MIL-STD-750 method 2026 solderability requirements.
SMBJ8.5CA-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJ, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 8.5V
- Voltage - Breakdown (Min):
- 9.4V
- Voltage - Clamping (Max) @ Ipp:
- 19.5V
- Current - Peak Pulse (10/1000µs):
- 41.7A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
SMBJ8.5CA-TR FAQ
1.How can I place an order for SMBJ8.5CA-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ8.5CA-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 SMBJ8.5CA-TR reliable?
The price and inventory of SMBJ8.5CA-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ8.5CA-TR is usually 5 days.
3.What payment methods are accepted for SMBJ8.5CA-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ8.5CA-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ8.5CA-TR?
SMBJ8.5CA-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ8.5CA-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 SMBJ8.5CA-TR?
For technical support, including SMBJ8.5CA-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ8.5CA-TR requirements.
6.How does Aetrix verify that SMBJ8.5CA-TR is sourced from the original manufacturer or authorized distributors?
All SMBJ8.5CA-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 SMBJ8.5CA-TR meets industry standards.
7.What is the process for return or replacement of SMBJ8.5CA-TR?
All SMBJ8.5CA-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ8.5CA-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 SMBJ8.5CA-TR part is unused and in its original packaging.
Return procedure for SMBJ8.5CA-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ8.5CA-TR Tags
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onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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