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STMicroelectronics SMC50J85CA
- Part No.:
- SMC50J85CA
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMC50J85CA.pdf
- Description:
- Linear IC's
- Quantity:
- Payment:
- Shipping:
Inventory:5,265
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Product details
Overview
SMC50J85CA from STMicroelectronics is a bidirectional transient voltage suppression (TVS) diode designed for high-energy ESD and surge protection in power rails and signal lines. It delivers 5000 W peak pulse power (10/1000 µs), clamps at 137 V (max) under 32 A IPP, and operates up to 175 °C junction temperature - enabling robust protection in industrial motor drives, telecom power supplies, and automotive body control modules.
For engineers reviewing the SMC50J85CA datasheet, SMC50J85CA pinout, SMC50J85CA application, or SMC50J85CA equivalent, key selection criteria include its 85 V standoff voltage, bidirectional configuration, low 0.2 µA leakage at 25 °C, JEDEC-registered SMC package, and IEC 61000-4-2 ±30 kV contact/air discharge compliance.
Technical Context
This planar-junction TVS diode uses silicon avalanche technology to provide fast response (<1 ns) to transients while maintaining low dynamic resistance (275 mΩ at 8/20 µs). Its bidirectional symmetry ensures identical clamping behavior for positive and negative surges, eliminating polarity concerns in AC-coupled or floating interfaces.
The device is rated for 175 °C maximum junction temperature and exhibits predictable voltage drift with temperature (αT = 10.6 × 10−4/°C), enabling accurate clamping margin calculation across operating conditions. Thermal impedance is optimized for FR4 PCBs with recommended copper area per lead (≥3.5 cm²).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 85 V - maximum continuous reverse working voltage before significant leakage begins; defines upper limit of protected circuit's normal operating range. |
| Breakdown Voltage (VBR) | 95–105 V at 1 mA - precise avalanche onset threshold ensuring reliable triggering without premature conduction during nominal operation. |
| Clamping Voltage (VCL) | 137 V max at 32 A (10/1000 µs) - peak voltage seen by downstream circuit during worst-case surge; determines minimum required voltage margin for protected ICs. |
| Peak Pulse Power (PPP) | 5000 W (10/1000 µs) - energy-handling capability for standard lightning/surge waveforms; supports IEC 61000-4-5 Level 3 (1 kV line-to-line) protection. |
| Leakage Current (IRM) | 0.2 µA max at 25 °C - negligible standby power loss and minimal impact on high-impedance sensor or reference circuits. |
| Junction Temperature Range | −55 to +175 °C - enables deployment in under-hood automotive, industrial inverters, and outdoor telecom equipment without derating. |
| ESD Rating | ±30 kV (IEC 61000-4-2, contact & air) - exceeds Level 4 immunity requirements, eliminating need for secondary ESD stages in many front-end designs. |
Pinout & Package
SMC50J85CA is housed in a JEDEC-registered SMC (DO-214AB) surface-mount package with matte tin-plated leads, compatible with standard reflow profiles (J-STD-020 MSL level 1). The bidirectional configuration has no anode/cathode distinction; both terminals are functionally symmetric.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Terminal 1 | Surge Input / Line Terminal | Connects to unprotected side (e.g., connector, bus line); conducts transient current bidirectionally to Terminal 2. |
| Terminal 2 | Surge Return / Common Reference | Typically tied to system ground or return path; completes low-inductance surge current loop with Terminal 1. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional Surge Protection | Identical clamping for ± transients eliminates polarity-sensitive layout constraints and simplifies design for AC or floating interfaces. |
| High-Temperature Operation | Rated to 175 °C junction temperature - maintains full surge rating in thermally demanding environments without derating. |
| Low Dynamic Resistance | 275 mΩ (at 8/20 µs) - minimizes clamping voltage rise under high-current surges, improving protection margin for sensitive downstream components. |
| JEDEC-Compliant SMC Package | Standardized mechanical outline (EIA-481 compliant tape/reel) ensures compatibility with automated pick-and-place and reflow processes. |
| UL94 V0 Flame Rating | Self-extinguishing epoxy housing meets safety standards for enclosed industrial and automotive enclosures. |
Applications
| Industrial Motor Drives | Telecom Power Supplies |
|---|---|
|
Use Scenario: Protection of DC bus inputs against load dump and inductive switching transients in 48 V motor controllers. IC Role / Device Role / Timing Role: Primary surge clamp placed between input terminal and ground plane, absorbing >5000 W pulses without failure. Use Value: Prevents MOSFET gate oxide damage and controller IC latch-up during field-installation cable disconnect events. |
Use Scenario: Input-stage protection for 48 V telecom rectifiers exposed to lightning-induced surges on outdoor feeder lines. IC Role / Device Role / Timing Role: First-line transient suppressor upstream of bulk capacitors and active PFC stage. Use Value: Limits clamped voltage to 137 V, keeping downstream SiC MOSFETs within safe SOA during 10/1000 µs surges. |
| Automotive Body Control Modules | Smart Meter Interfaces |
|
Use Scenario: CAN FD and LIN bus line protection in BCMs subjected to ISO 7637-2 pulse 1/2a/5a transients. IC Role / Device Role / Timing Role: Bidirectional TVS placed across differential pairs to suppress common-mode surges without distorting signal integrity. Use Value: Maintains <0.2 µA leakage at 85 V standoff, avoiding bias current errors in precision current-sense amplifiers. |
Use Scenario: RS-485 and PLC communication port protection in utility smart meters installed in electrically noisy substations. IC Role / Device Role / Timing Role: Low-capacitance (≈100 pF) bidirectional clamp minimizing signal edge degradation at 1 Mbps data rates. Use Value: Withstands repeated ±30 kV ESD strikes per IEC 61000-4-2 without parameter shift or catastrophic failure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ85CA (Bourns) | Same 85 V VRM and bidirectional configuration, but lower PPP (600 W) and higher VCL (139 V at 24.9 A). | Limited to lower-energy surges; unsuitable for IEC 61000-4-5 Level 3+ or high-power industrial inputs. | Select when cost sensitivity outweighs surge energy requirement and board space permits larger footprint. |
| TPSMD85CA (Littelfuse) | Identical 85 V VRM and 5000 W rating, but higher leakage (1 µA) and wider VCL tolerance (137–145 V). | May compromise accuracy in high-impedance sensing nodes; requires tighter layout control for thermal management. | Prefer where Littelfuse supply chain alignment or dual-sourcing mandates override minor leakage trade-off. |
Compared with SMBJ85CA and TPSMD85CA, SMC50J85CA offers superior thermal stability (175 °C Tj max), lower leakage (0.2 µA), and tighter VCL consistency - making it optimal for high-reliability industrial and automotive applications where long-term parametric drift must be minimized.
Availability
SMC50J85CA is available at Aetrix Electronics and suitable for industrial motor drives, telecom power supplies, automotive body control modules, and smart meter interfaces requiring stable component supply across extended product lifecycles.
Supply support for SMC50J85CA 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 SMC50J TVS series targets high-reliability surge protection in harsh environments, emphasizing high-temperature operation, low leakage, and standardized packaging for seamless integration into automated manufacturing.
FAQ
What is the maximum clamping voltage for SMC50J85CA under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 137 V at 32 A peak pulse current for a 10/1000 µs waveform, measured at Tj = 25 °C. This value increases predictably with junction temperature using αT = 10.6 × 10−4/°C, reaching ~145 V at 125 °C.
Is SMC50J85CA unidirectional or bidirectional, and how is polarity identified?
SMC50J85CA is a bidirectional TVS diode, meaning it provides symmetrical clamping for both positive and negative transients. Unlike unidirectional versions (e.g., SMC50J85A), it has no cathode bar marking - the device is functionally identical on both terminals and requires no orientation during placement.
Can SMC50J85CA replace SMCJ85CA in existing designs?
Yes, SMC50J85CA is a direct replacement for SMCJ85CA with identical SMC package, 85 V standoff, and bidirectional functionality. It improves upon SMCJ85CA with higher peak power (5000 W vs. 1500 W), lower leakage (0.2 µA vs. 1 µA), and extended temperature rating (175 °C vs. 150 °C).
What PCB layout practices maximize thermal performance for SMC50J85CA?
Maximize copper area under each lead (≥3.5 cm² per terminal on inner layers), use thermal vias to internal ground planes, and avoid narrow traces between the device and ground. The datasheet specifies Rth(j-a) drops from 120 °C/W (no copper) to <40 °C/W with optimal layout - critical for sustaining repeated surge events.
SMC50J85CA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- SMC50J
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 85V (Max)
- Voltage - Breakdown (Min):
- 95V
- Voltage - Clamping (Max) @ Ipp:
- 137V
- Current - Peak Pulse (10/1000µs):
- 32A
- Power - Peak Pulse:
- 5000W (5kW)
- 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:
- SMC
SMC50J85CA FAQ
1.How can I place an order for SMC50J85CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SMC50J85CA 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 SMC50J85CA reliable?
The price and inventory of SMC50J85CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMC50J85CA is usually 5 days.
3.What payment methods are accepted for SMC50J85CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMC50J85CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMC50J85CA?
SMC50J85CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMC50J85CA 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 SMC50J85CA?
For technical support, including SMC50J85CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMC50J85CA requirements.
6.How does Aetrix verify that SMC50J85CA is sourced from the original manufacturer or authorized distributors?
All SMC50J85CA 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 SMC50J85CA meets industry standards.
7.What is the process for return or replacement of SMC50J85CA?
All SMC50J85CA units undergo pre-shipment inspection (PSI). If there is an issue with SMC50J85CA, 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 SMC50J85CA part is unused and in its original packaging.
Return procedure for SMC50J85CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMC50J85CA Tags
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