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STMicroelectronics SMC50J31CA
- Part No.:
- SMC50J31CA
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMC50J31CA.pdf
- Description:
- Linear IC's
- Quantity:
- Payment:
- Shipping:
Inventory:2,462
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Product details
Overview
SMC50J31CA from STMicroelectronics is a bidirectional transient voltage suppression (TVS) diode designed for high-energy ESD and surge protection in DC power rails and signal lines. It delivers 5000 W peak pulse power (10/1000 µs), clamps at 50.2 V (max) under 100 A surge, and operates up to 175 °C junction temperature - enabling robust protection in automotive infotainment power supplies and industrial I/O interfaces.
For engineers reviewing the SMC50J31CA datasheet, SMC50J31CA pinout, SMC50J31CA application, or SMC50J31CA equivalent, key selection criteria include its 31 V standoff voltage, bidirectional polarity, low 0.2 µA leakage at 25 °C, JEDEC-registered SMC package, and compliance with IEC 61000-4-2 (±30 kV contact/air) and IEC 61000-4-4 Level 4 (4 kV).
Technical Context
This planar-junction TVS diode uses silicon avalanche technology to provide fast response (<1 ns) to electrostatic discharge and repetitive electrical overstress events. Its bidirectional configuration enables symmetrical clamping on AC-coupled or floating lines without polarity dependency.
The device features a dynamic resistance of 9.9 mΩ (typical) at 10/1000 µs, enabling low clamping voltage rise under high-current transients, and maintains stable VBR across -55 °C to +175 °C via temperature coefficient αT = 10×10−4/°C - critical for under-hood automotive and high-temperature SMPS designs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRWM) | 31 V - maximum continuous reverse working voltage before leakage exceeds 1 µA; defines safe operating margin for 24 V nominal systems. |
| Breakdown Voltage (VBR) | 34.2–37.8 V at 1 mA - ensures reliable triggering above system operating voltage while avoiding false trips during ripple or transients. |
| Clamping Voltage (VCL) | 50.2 V max at 100 A (10/1000 µs) - limits downstream voltage stress to <51 V during worst-case surge, protecting 3.3 V/5 V logic and 40 V-rated MOSFETs. |
| Peak Pulse Power | 5000 W (10/1000 µs); up to 626 W at Tj = 175 °C - sustains repeated surges in thermally constrained PCB layouts without derating. |
| Leakage Current | 0.2 µA max at 25 °C and VRWM - minimizes standby power loss in battery-backed sensors and always-on automotive modules. |
| Junction Temperature Range | -55 °C to +175 °C - supports operation in engine control units, motor drives, and industrial PLCs exposed to extreme ambient conditions. |
| ESD Robustness | ±30 kV contact & air discharge per IEC 61000-4-2 - exceeds Level 4 requirements, eliminating need for external ESD staging in USB, CAN, or RS-485 ports. |
Pinout & Package
SMC50J31CA is housed in a JEDEC-registered SMC (DO-214AB) surface-mount package with matte tin-plated leads and MSL Level 1 moisture sensitivity. The bidirectional configuration has no anode/cathode distinction; both terminals are electrically symmetric.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode (Terminals 1 & 2) | Bidirectional surge path | Both terminals serve as interchangeable surge current entry/exit points; no polarity marking required beyond cathode bar (per marking layout in DS13845 Fig.15). |
Key Features
| Feature | Design Value |
|---|---|
| High-temperature reliability | Rated for continuous operation at Tj = 175 °C - eliminates thermal derating in compact power converters and under-hood ECUs. |
| Low dynamic resistance | 9.9 mΩ typical - reduces VCL rise under high di/dt surges, improving clamping precision for sensitive analog front-ends. |
| JEDEC-compliant footprint | IPC-7531 recommended land pattern - ensures manufacturability across global EMS providers without custom stencil or reflow adjustments. |
| Whisker-resistant plating | JESD-201 Class 2 tin finish - prevents tin whisker growth in long-life industrial and aerospace applications. |
| UL94 V0 flammability rating | Self-extinguishing epoxy body - meets safety requirements for enclosed power supplies and medical equipment enclosures. |
Applications
| Automotive Body Control Module (BCM) | Industrial RS-485 Communication Port |
|---|---|
Use Scenario: Protects LIN bus power rail against load dump and jump-start transients in door module electronics. IC Role / Device Role / Timing Role: Bidirectional TVS clamp placed between VBAT and ground, absorbing >5000 W pulses without failure. Use Value: Prevents latch-up or destruction of 3.3 V microcontroller power domains during 12 V system surges, extending field reliability beyond 15-year vehicle life. |
Use Scenario: Shields RS-485 transceiver (e.g., SN65HVD230) from ESD events on differential A/B lines in factory automation networks. IC Role / Device Role / Timing Role: Symmetrical clamping device connected across A-B and A-GND/B-GND, suppressing ±30 kV contact discharge per IEC 61000-4-2. Use Value: Maintains data integrity during hot-plug cable insertion and eliminates field returns due to transceiver latch-up in unshielded factory environments. |
| Server PSU 48 V Intermediate Bus | Smart Meter Power Input Stage |
Use Scenario: Guards 48 V input stage of server power supply against lightning-induced surges on telecom-grade distribution lines. IC Role / Device Role / Timing Role: Primary surge suppressor mounted at board edge, clamping 10/1000 µs transients before bulk capacitors and PFC controller. Use Value: Limits peak voltage to ≤51 V during 4 kV IEC 61000-4-4 events, preventing overvoltage shutdown of 60 V-rated GaN FETs and maintaining uptime SLA compliance. |
Use Scenario: Secures AC/DC adapter input in utility smart meters exposed to grid switching transients and induced surges on metering transformers. IC Role / Device Role / Timing Role: Bidirectional TVS placed across rectified DC output, absorbing repetitive 100 A surges without degradation over 20+ year service life. Use Value: Achieves >100,000 surge cycles at rated power per IEC 61000-4-5, eliminating field failures in outdoor-mounted meters subjected to frequent lightning proximity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ33CA | Lower peak power (600 W vs. 5000 W); same 33 V VRWM; SMB package (smaller footprint, higher thermal resistance). | Not suitable for >1 kA surge events; limited to low-energy signal-line protection (e.g., USB D+/D−). | Select only when space constraints prohibit SMC and surge energy remains below 1 kW. |
| 1.5KE33CA | Higher leakage (5 µA vs. 0.2 µA); axial leaded DO-201 package; 1500 W rating; no MSL or reflow compatibility. | Requires through-hole assembly; unsuitable for automated SMT production or high-reliability thermal cycling environments. | Consider only for legacy repair or non-SMT prototyping where reflow compatibility is not required. |
Compared with SMBJ33CA and 1.5KE33CA, SMC50J31CA provides 8.3× higher surge power handling, 25× lower leakage, and full SMT manufacturability - making it the sole choice for high-reliability, high-energy DC bus protection in automotive and industrial power systems.
Availability
SMC50J31CA is available at Aetrix Electronics and suitable for automotive body electronics, industrial communication ports, server power supplies, and smart metering systems requiring stable component supply across extended product lifecycles.
Supply support for SMC50J31CA 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, automotive ICs, and protection devices with vertical manufacturing and AEC-Q101 qualification capabilities.
The SMC50J series belongs to ST's high-power TVS portfolio engineered specifically for automotive-grade transient immunity and industrial-grade surge resilience - targeting applications where failure modes must be eliminated under extreme thermal and electrical stress.
FAQ
What is the maximum clamping voltage of SMC50J31CA at 100 A (10/1000 µs)?
The maximum clamping voltage is 50.2 V under 100 A, 10/1000 µs surge conditions per Table 2 of DS13845 Rev 1. This value is measured at Tj = 25 °C and scales with junction temperature using αT = 10×10−4/°C - at 150 °C, VCL rises to approximately 53.7 V.
Is SMC50J31CA unidirectional or bidirectional?
SMC50J31CA is a bidirectional TVS diode, indicated by the "CA" suffix per ST's ordering nomenclature (Table 5). Its symmetrical breakdown behavior allows clamping of both positive and negative transients without polarity orientation constraints on the PCB.
Does SMC50J31CA meet automotive AEC-Q101 qualification?
Yes - SMC50J31CA is AEC-Q101 qualified per ST's official product documentation and device status links. It undergoes stress testing including HTGB, HTRB, and temperature cycling to ensure reliability in automotive under-hood environments up to 175 °C junction temperature.
What is the recommended PCB footprint for SMC50J31CA?
The recommended footprint follows IPC-7531 and is specified in DS13845 Figure 14: pad length 5.11 mm, pad width 1.54 mm, center-to-center spacing 8.19 mm, and copper area per pad ≥3.14 cm² to achieve Rth(j-a) ≤ 100 °C/W per Figure 12 - critical for sustaining 5000 W pulses without thermal runaway.
SMC50J31CA 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):
- 31V (Max)
- Voltage - Breakdown (Min):
- 34.2V
- Voltage - Clamping (Max) @ Ipp:
- 50.2V
- Current - Peak Pulse (10/1000µs):
- 100A
- 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
SMC50J31CA FAQ
1.How can I place an order for SMC50J31CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SMC50J31CA 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 SMC50J31CA reliable?
The price and inventory of SMC50J31CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMC50J31CA is usually 5 days.
3.What payment methods are accepted for SMC50J31CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMC50J31CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMC50J31CA?
SMC50J31CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMC50J31CA 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 SMC50J31CA?
For technical support, including SMC50J31CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMC50J31CA requirements.
6.How does Aetrix verify that SMC50J31CA is sourced from the original manufacturer or authorized distributors?
All SMC50J31CA 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 SMC50J31CA meets industry standards.
7.What is the process for return or replacement of SMC50J31CA?
All SMC50J31CA units undergo pre-shipment inspection (PSI). If there is an issue with SMC50J31CA, 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 SMC50J31CA part is unused and in its original packaging.
Return procedure for SMC50J31CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMC50J31CA Tags
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