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STMicroelectronics SMCJ85CA-TR
- Part No.:
- SMCJ85CA-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ85CA-TR.pdf
- Description:
- TVS DIODE 85VWM 178VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:4,527
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Product details
Overview
SMCJ85CA-TR from STMicroelectronics is a bidirectional 1500 W transient voltage suppression (TVS) diode in SMC package, designed for high-energy ESD and surge protection in DC power rails and signal lines. It features a standoff voltage (VRM) of 85 V, clamping voltage (VCL) of 137 V at 11.5 A (10/1000 µs), and operates up to 150 °C junction temperature - deployed in industrial power supplies and telecom interface protection.
For engineers reviewing the SMCJ85CA-TR datasheet, SMCJ85CA-TR pinout, SMCJ85CA-TR application, or SMCJ85CA-TR equivalent, key selection criteria include bidirectional clamping capability, low leakage (<0.2 µA at 25 °C), IEC 61000-4-2 ±30 kV contact/air discharge compliance, and thermal derating above 25 °C ambient.
Technical Context
This TVS diode uses planar silicon avalanche technology to deliver symmetric clamping in both polarities, enabling robust protection against reverse-polarity surges and bipolar transients without external polarity management. Its dynamic resistance (RD) of 2.87 Ω at 25 °C ensures predictable voltage overshoot under fast-rising 8/20 µs surges.
The device complies with IEC 61000-4-4 Level 4 (4 kV), exceeds IEC 61000-4-2 Level 4 (±30 kV), and maintains stable VBR (94–99 V) across -55 °C to +150 °C via temperature coefficient αT = 10.6 × 10⁻⁴ /°C - critical for automotive and industrial environments with wide thermal cycling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power (10/1000 µs) | 1500 W - sustains full-rated surge energy at 25 °C ambient; derates to 1250 W at Tj = 150 °C |
| Standoff Voltage (VRM) | 85 V - maximum continuous DC or RMS voltage before conduction begins; defines operating rail margin |
| Breakdown Voltage (VBR) | 94–99 V at 1 mA - precise avalanche onset threshold ensuring early clamping before downstream IC damage |
| Clamping Voltage (VCL) | 137 V at 11.5 A (10/1000 µs) - peak voltage seen by protected circuit during worst-case surge |
| Leakage Current (IRM) | 0.2 µA max at VRM = 85 V and 25 °C - negligible standby power loss and minimal impact on high-impedance sensing nodes |
| Junction Temperature Range | -55 °C to +150 °C - supports operation in under-hood automotive, industrial motor drives, and outdoor telecom enclosures |
| ESD Withstand (IEC 61000-4-2) | ±30 kV air/contact discharge - exceeds Level 4, eliminating need for secondary ESD stages in front-end interfaces |
Pinout & Package
SMCJ85CA-TR is housed in an industry-standard SMC (DO-214AB) surface-mount package with two terminals: Cathode (K) and Anode (A). The bidirectional configuration means both terminals function identically under reverse or forward surge polarity - no orientation dependency during PCB placement.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Surge current entry point (positive polarity) | Connects to line being protected; forms one side of symmetrical avalanche path |
| Cathode (K) | Surge current entry point (negative polarity) | Connects to line being protected; completes bidirectional clamping loop with Anode |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating lines without polarity awareness - reduces BOM count vs. unidirectional pairs |
| Low dynamic resistance (2.87 Ω) | Minimizes VCL rise under high-current surges (e.g., 8/20 µs lightning), improving margin for 100 V-rated downstream components |
| High-temperature operation (150 °C) | Supports placement near heat-generating components (e.g., MOSFETs, inductors) without derating penalties in compact power designs |
| UL94 V0 epoxy housing | Meets flammability safety requirements for enclosed industrial and medical equipment without additional conformal coating |
| JEDEC-compliant SMC footprint | Ensures mechanical compatibility with automated pick-and-place and reflow processes using standard IPC-7351B land patterns |
Applications
| Industrial Power Supply Input Protection | Telecom Line Interface Protection |
|---|---|
Use Scenario: 48 V DC input stage of programmable logic controller (PLC) power module exposed to load dump and inductive switching transients. IC Role / Device Role / Timing Role: Primary surge shunt device placed directly across input rails before bulk capacitor and upstream DC/DC converter. Use Value: Clamps 1500 W surges to ≤137 V, preventing overvoltage failure of 100 V-rated input MOSFETs and electrolytic capacitors. |
Use Scenario: RS-485 data line termination in outdoor base station equipment subject to lightning-induced ground potential rise. IC Role / Device Role / Timing Role: Bidirectional transient suppressor bridging differential pair (A/B) to ground, absorbing common-mode surges. Use Value: Symmetric clamping preserves signal integrity during ±30 kV ESD events while maintaining <1 nA leakage at 48 V bias. |
| Automotive Body Control Module (BCM) | Renewable Energy Inverter DC Link |
Use Scenario: 12 V battery-supplied microcontroller I/O lines in BCM exposed to ISO 7637-2 pulse 1/2a/5a transients. IC Role / Device Role / Timing Role: Secondary-level protection after LC filter, placed adjacent to MCU pins to limit residual clamped voltage. Use Value: 150 °C rating allows mounting in sealed enclosure with no forced airflow; 0.2 µA leakage avoids sensor offset drift. |
Use Scenario: DC bus protection in solar string inverters where PV array fault currents can generate >1000 V spikes during arc faults. IC Role / Device Role / Timing Role: Parallel-connected TVS bank across 800 V DC link to clamp fast transients before IGBT gate drivers. Use Value: 137 V clamping at 11.5 A enables staged protection architecture with upstream MOVs - extends system lifetime under repeated surges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ85CA-TR | Lower peak power (600 W), same VRM/VBR, SMB package (smaller footprint, higher thermal resistance) | Limited to lower-energy surges; unsuitable for IEC 61000-4-4 Level 4 or 1500 W 10/1000 µs events | Select only when space-constrained and surge threat level is ≤600 W - verify thermal margin at 150 °C |
| 1.5KE85CA | Same 1500 W rating but axial DO-201 package; higher leakage (5 µA), no JEDEC SMC footprint | Requires through-hole assembly; incompatible with automated SMT lines and high-density layouts | Choose only for legacy through-hole designs or prototyping where rework tolerance outweighs production efficiency |
Compared with SMBJ85CA-TR and 1.5KE85CA, SMCJ85CA-TR uniquely balances 1500 W surge handling, SMT manufacturability, and ultra-low leakage in a thermally robust SMC package - making it optimal for volume production of industrial and telecom systems requiring repeatable surge immunity.
Availability
SMCJ85CA-TR is available at Aetrix Electronics and suitable for industrial power supply input protection, telecom line interface protection, automotive body control modules, and renewable energy inverter DC link applications requiring stable component supply and long-term lifecycle support.
Supply support for SMCJ85CA-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 microcontrollers - serving automotive, industrial, and consumer markets with AEC-Q100-qualified and industrial-grade components.
SMCJxxCA belongs to ST's high-power TVS diode product line, engineered specifically for robust electrostatic and surge protection in harsh-environment power electronics - emphasizing low leakage, high-temperature stability, and IEC/UL compliance.
FAQ
What is the difference between SMCJ85CA-TR and SMCJ85A-TR?
SMCJ85CA-TR is bidirectional, providing symmetrical clamping for both positive and negative transients across its terminals, while SMCJ85A-TR is unidirectional and requires correct anode/cathode orientation relative to the protected line polarity. This makes the CA version ideal for AC-coupled or floating signals, whereas the A version suits DC rails with defined ground reference.
Can SMCJ85CA-TR be used in parallel for higher surge current handling?
Yes, but only with careful layout: matched trace lengths, identical thermal vias, and symmetrical copper pour under each device to ensure current sharing. ST does not guarantee balanced current division beyond two devices; for >30 A total IPP, consider higher-rated alternatives like 5.0SMDJ85CA or discrete MOV+TVS hybrid designs.
Does SMCJ85CA-TR meet AEC-Q200 stress testing requirements?
No - SMCJ85CA-TR is qualified to industrial temperature grade (-55 °C to +150 °C) and meets IEC/UL safety standards, but it is not AEC-Q200 certified. For automotive under-hood applications requiring AEC-Q200 qualification, ST recommends the SMAJ85CA-Q or SMF85CA-Q series, which undergo additional vibration, humidity, and temperature cycling tests.
How does junction temperature affect clamping voltage performance?
VCL increases with junction temperature at a rate of αT = 10.6 × 10⁻⁴ /°C; at 150 °C, VCL rises ~1.33 V above its 25 °C value (137 V → ~138.3 V). This small shift is factored into ST's derating curves and remains within safe margins for 100 V-rated components - no design adjustment needed for thermal drift.
SMCJ85CA-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- SMCJ, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 85V
- Voltage - Breakdown (Min):
- 94V
- Voltage - Clamping (Max) @ Ipp:
- 178V
- Current - Peak Pulse (10/1000µs):
- 56A (8/20µs)
- Power - Peak Pulse:
- 1500W (1.5kW)
- 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:
- SMC
SMCJ85CA-TR FAQ
1.How can I place an order for SMCJ85CA-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ85CA-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 SMCJ85CA-TR reliable?
The price and inventory of SMCJ85CA-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ85CA-TR is usually 5 days.
3.What payment methods are accepted for SMCJ85CA-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ85CA-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ85CA-TR?
SMCJ85CA-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ85CA-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 SMCJ85CA-TR?
For technical support, including SMCJ85CA-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ85CA-TR requirements.
6.How does Aetrix verify that SMCJ85CA-TR is sourced from the original manufacturer or authorized distributors?
All SMCJ85CA-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 SMCJ85CA-TR meets industry standards.
7.What is the process for return or replacement of SMCJ85CA-TR?
All SMCJ85CA-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ85CA-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 SMCJ85CA-TR part is unused and in its original packaging.
Return procedure for SMCJ85CA-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ85CA-TR Tags
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