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STMicroelectronics SMC30J18CA
- Part No.:
- SMC30J18CA
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMC30J18CA.pdf
- Description:
- TVS DIODE 18VWM 29.2VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:7,325
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Product details
Overview
SMC30J18CA from STMicroelectronics is a bidirectional transient voltage suppression (TVS) diode designed for high-energy ESD and surge protection in power and signal lines. It delivers 3000 W peak pulse power (10/1000 µs), clamps at 29.2 V (max) under 103 A surge current, 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 SMC30J18CA datasheet, SMC30J18CA pinout, SMC30J18CA application, or SMC30J18CA equivalent, key selection criteria include its 18 V standoff voltage, bidirectional polarity, low 0.2 µA leakage at 25 °C, JEDEC-standard 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 surges. Its bidirectional configuration enables symmetrical clamping across both polarities without external circuitry, supporting AC-coupled interfaces and differential bus protection.
The device features a dynamic resistance of 21.4 mΩ (typical), enabling low clamping voltage rise under high-current transients, and exhibits stable thermal performance up to 175 °C - validated per JESD22-A103 and MIL-STD-750 Method 2026.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 18 V - maximum continuous reverse operating voltage before significant leakage begins |
| Breakdown Voltage (VBR min) | 20 V at 1 mA - guaranteed avalanche initiation threshold for reliable triggering |
| Clamping Voltage (VCL max) | 29.2 V at 103 A (10/1000 µs) - peak voltage seen by protected circuit during worst-case surge |
| Peak Pulse Power (PPP) | 3000 W (10/1000 µs) - sustained energy-handling capability for industrial-grade surge immunity |
| Leakage Current (IRM) | 0.2 µA at 18 V, 25 °C - negligible standby power loss and minimal impact on high-impedance sensing nodes |
| Junction Temperature Range | –55 °C to +175 °C - supports operation in under-hood automotive, industrial inverters, and outdoor telecom equipment |
| ESD Withstand (IEC 61000-4-2) | ±30 kV contact & air discharge - exceeds Level 4 requirements for front-panel and connector-level protection |
Pinout & Package
SMC30J18CA is housed in a JEDEC-standard SMC (DO-214AB) surface-mount package with matte tin-plated leads, optimized for automated assembly and high thermal reliability. The package measures 7.75–8.15 mm × 5.55–6.25 mm × 2.45 mm max height and supports IPC-7531-compliant footprint layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (K) | Surge current sink (bidirectional reference) | Internal connection point for both avalanche junctions; serves as common terminal for symmetrical clamping |
| Anode (A) | Surge current sink (bidirectional reference) | Second terminal forming the bidirectional path; no polarity distinction - interchangeable with K in layout |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC lines, RS-485, CAN FD, and Ethernet PHYs without polarity concerns |
| Low dynamic resistance (21.4 mΩ) | Minimizes clamping voltage overshoot during fast-rising surges, improving system-level immunity margin |
| High junction temperature rating (175 °C) | Supports placement near heat-generating components (e.g., MOSFETs, inductors) without derating |
| UL94 V0 flammability rating | Ensures PCB-level fire safety compliance in enclosed industrial and medical enclosures |
| JEDEC MSL Level 1 | Zero floor-life limitation - can be stored indefinitely at ≤30 °C/85 % RH prior to reflow |
Applications
| Industrial Motor Drives | Telecom DC Power Input |
|---|---|
|
Use Scenario: Protection of 24 V DC input stage against lightning-induced surges and inductive kickback from contactors. IC Role / Device Role / Timing Role: Primary surge shunt device placed directly at connector entry point, clamping transients before they reach upstream DC-DC converters. Use Value: Maintains 29.2 V clamping under 103 A surge, preventing overvoltage damage to 36 V-rated input capacitors and controller ICs. |
Use Scenario: Front-end protection of -48 V telecom rectifier outputs feeding distributed power architecture. IC Role / Device Role / Timing Role: Bidirectional clamp across output rails to suppress both positive and negative polarity surges from shared return paths. Use Value: 0.2 µA leakage ensures no measurable impact on tight -48 V regulation tolerance, while 3000 W rating handles repeated 10/1000 µs line surges. |
| Automotive Body Control Module | RS-485 Industrial Bus Node |
|
Use Scenario: CAN and LIN bus line protection in BCMs exposed to load dump and jump-start transients. IC Role / Device Role / Timing Role: Secondary-level TVS placed after common-mode chokes to absorb differential-mode ESD events on data lines. Use Value: ±30 kV IEC 61000-4-2 rating meets ISO 10605 requirements for interior electronics, with 175 °C operation surviving under-dash thermal environments. |
Use Scenario: Transient suppression on RS-485 A/B differential pairs in factory automation PLC I/O modules. IC Role / Device Role / Timing Role: Bidirectional TVS connected between A and B lines to clamp differential surges without disrupting DC bias. Use Value: Symmetrical 29.2 V clamping preserves receiver common-mode range and prevents false logic transitions during 4 kV IEC 61000-4-4 bursts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ18CA (Bourns) | Lower PPP (600 W), higher VCL (32.4 V at 18.6 A), SMB package (smaller footprint, lower thermal mass) | Limited to lower-energy surges; unsuitable for 3000 W IEC 61000-4-4 Level 4 compliance | Select only when space-constrained and surge threat level is <1 kW (e.g., consumer USB ports) |
| 1.5KE18CA (ON Semiconductor) | Through-hole DO-201 package, same 18 V VRM, but slower response (>5 ns) and higher VCL (33.2 V at 91 A) | Not suitable for high-speed data lines or automated SMT production; requires wave soldering | Choose only for legacy through-hole designs where board real estate is not constrained and reflow compatibility is not required |
Compared with SMBJ18CA and 1.5KE18CA, SMC30J18CA uniquely combines 3000 W surge handling, sub-30 V clamping, SMT scalability, and 175 °C operation - making it the only option qualified for high-reliability industrial and automotive power rail protection where thermal and energy margins are critical.
Availability
SMC30J18CA is available at Aetrix Electronics and suitable for industrial motor drives, telecom DC power inputs, automotive body control modules, and RS-485 industrial bus nodes requiring stable component supply, long-term lifecycle support, and full compliance with IEC 61000-4-2/4-4 standards.
Supply support for SMC30J18CA 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 microcontroller technologies for industrial, automotive, and consumer markets.
SMC30JxxA/CA belongs to ST's high-power TVS diode product line, engineered specifically for robust front-end surge protection in harsh-environment power systems where reliability, thermal resilience, and standardized packaging are mandatory.
FAQ
What is the difference between SMC30J18A and SMC30J18CA?
SMC30J18A is unidirectional (anode-to-cathode conduction only), while SMC30J18CA is bidirectional - meaning it clamps symmetrically for both positive and negative voltage transients. This makes the 'CA' version ideal for AC-coupled or differential signal lines like RS-485 or CAN, whereas the 'A' version suits DC power rail protection with defined polarity.
Can SMC30J18CA be used in parallel for higher surge current handling?
No - paralleling TVS diodes is not recommended due to mismatched breakdown voltages causing uneven current sharing and premature failure. For higher current needs, select a higher-rated part (e.g., SMC30J22CA or SMC30J24CA) or use staged protection with upstream current-limiting resistors and downstream low-capacitance TVS devices.
Does SMC30J18CA require a heatsink for 3000 W surge dissipation?
No external heatsink is needed for single-event 3000 W (10/1000 µs) surges because energy is dissipated in microseconds. Thermal design focuses on PCB copper area: ST recommends ≥3 cm² of 70 µm copper per lead to maintain Rth(j-a) ≤ 4.5 °C/W and prevent junction overheating during repetitive events.
Is SMC30J18CA compliant with AEC-Q200 for automotive use?
SMC30J18CA is not AEC-Q200 qualified. While it operates up to 175 °C and meets IEC 61000-4-2/4-4, ST does not list it in their AEC-Q200 stress-tested portfolio. For automotive-critical applications, consider ST's Automotive Qualified SMAJ18CA or SMAJ18A series, which undergo full AEC-Q200 temperature cycling, humidity, and vibration testing.
SMC30J18CA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- SMC30J
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 29.2V
- Current - Peak Pulse (10/1000µs):
- 103A
- Power - Peak Pulse:
- 3000W (3kW)
- 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
SMC30J18CA FAQ
1.How can I place an order for SMC30J18CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SMC30J18CA 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 SMC30J18CA reliable?
The price and inventory of SMC30J18CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMC30J18CA is usually 5 days.
3.What payment methods are accepted for SMC30J18CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMC30J18CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMC30J18CA?
SMC30J18CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMC30J18CA 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 SMC30J18CA?
For technical support, including SMC30J18CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMC30J18CA requirements.
6.How does Aetrix verify that SMC30J18CA is sourced from the original manufacturer or authorized distributors?
All SMC30J18CA 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 SMC30J18CA meets industry standards.
7.What is the process for return or replacement of SMC30J18CA?
All SMC30J18CA units undergo pre-shipment inspection (PSI). If there is an issue with SMC30J18CA, 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 SMC30J18CA part is unused and in its original packaging.
Return procedure for SMC30J18CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMC30J18CA Tags
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