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STMicroelectronics SMCJ18CA-TR
- Part No.:
- SMCJ18CA-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ18CA-TR.pdf
- Description:
- TVS DIODE 18VWM 39.3VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:3,088
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Product details
Overview
SMCJ18CA-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 18 V, minimum breakdown voltage (VBR) of 20 V at 1 mA, clamping voltage (VCL) of 29.2 V at 53 A (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 SMCJ18CA-TR datasheet, SMCJ18CA-TR pinout, SMCJ18CA-TR application, or SMCJ18CA-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 junction technology to achieve stable reverse breakdown with minimal capacitance drift over temperature. Its bidirectional architecture enables symmetric clamping on AC-coupled or floating lines without polarity constraints.
It delivers 1500 W peak pulse power (10/1000 µs) at 25 °C, derating to 1250 W at Tj = 150 °C, and supports 8/20 µs surges up to 10 kW. Dynamic resistance (RD) is 0.133 Ω, enabling fast response to transients while maintaining low clamping overshoot.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 18 V - maximum continuous reverse operating voltage before leakage exceeds 0.2 µA |
| Breakdown Voltage (VBR) | 20–21.1 V at 1 mA - ensures reliable triggering during overvoltage events without premature conduction |
| Clamping Voltage (VCL) | 29.2 V at 53 A (10/1000 µs) - limits downstream voltage stress to safe levels for 18 V-rated ICs |
| Peak Pulse Power (PPP) | 1500 W (10/1000 µs) - protects against lightning-induced surges per IEC 61000-4-5 Level 3 |
| Leakage Current (IRM) | ≤0.2 µA at VRM = 18 V and 25 °C - avoids parasitic loading on low-power sensor or battery-backed circuits |
| Junction Temperature Range | −55 to +150 °C - supports operation in under-hood automotive and industrial environments |
| ESD Robustness | ±30 kV air/contact discharge per IEC 61000-4-2 Level 4 - exceeds standard requirements for user-interface ports |
Pinout & Package
SMCJ18CA-TR is housed in an 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 conditions - no polarity marking required for layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Surge current entry point (bidirectional) | Accepts transient energy from either polarity; connects to protected line without orientation constraint |
| Cathode (K) | Surge current return path (bidirectional) | Completes low-impedance path to ground or reference rail during clamping event |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC signals, differential buses (e.g., RS-485), or floating power domains |
| Low dynamic resistance (RD) | 0.133 Ω minimizes clamping voltage rise under high-current surges, improving protection margin |
| High-temperature operation | Rated for full 1500 W pulse power up to 150 °C junction temperature - reduces need for thermal derating in compact layouts |
| UL94 V0 epoxy housing | Ensures flame-retardant PCB mounting compliance in safety-critical industrial and medical equipment |
| JEDEC-standard SMC footprint | Guarantees mechanical compatibility with automated placement and reflow processes across contract manufacturers |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: 24 V DC input rail in programmable logic controller (PLC) power stage exposed to load dump and inductive switching noise. IC Role / Device Role / Timing Role: Bidirectional TVS placed between input and chassis ground to clamp transients before they reach DC-DC converter ICs. Use Value: Clamps 10/1000 µs surges to ≤29.2 V, protecting 36 V max-input buck controllers and reducing need for oversized input capacitors. |
Use Scenario: LIN bus transceiver supply line in door module subjected to ESD from human touch and cable coupling. IC Role / Device Role / Timing Role: TVS mounted directly at connector entry point to shunt ±30 kV ESD pulses away from LIN PHY IC. Use Value: Sub-µA leakage prevents battery drain in sleep mode; 150 °C rating supports under-dash mounting near HVAC ducts. |
| RS-485 Communication Port | Smart Meter AC Mains Interface |
Use Scenario: Differential data lines (A/B) of isolated RS-485 transceiver connected to outdoor utility infrastructure. IC Role / Device Role / Timing Role: Bidirectional TVS pair (one per line) referenced to common-mode ground to suppress common-mode surges. Use Value: Symmetric clamping maintains signal integrity during 8/20 µs surges up to 7.4 kA, preventing transceiver latch-up. |
Use Scenario: AC zero-crossing detection circuit powered from rectified mains, vulnerable to lightning-induced surges on neutral/line. IC Role / Device Role / Timing Role: TVS placed across bridge rectifier output to clamp overvoltage before it reaches microcontroller ADC input. Use Value: 29.2 V clamping ensures <30 V stress on 3.3 V MCU's internal ESD diodes, eliminating external series resistors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ18CA-TR | Lower peak power: 600 W (10/1000 µs); same VRM/VBR/VCL but higher RD (0.22 Ω) | Suitable only for lower-energy environments (e.g., consumer USB ports), not industrial load dump | Select when board space is constrained (SMB vs SMC) and surge threat level is ≤600 W |
| 1.5KE18CA | Through-hole DO-201 package; identical electrical specs but 10× higher thermal resistance (Rth(j-a) ≈ 100 °C/W vs 45 °C/W) | Requires larger copper pour and cannot sustain repeated surges in thermally limited enclosures | Choose only for legacy through-hole designs where rework to SMT is impractical |
Compared with SMBJ18CA-TR and 1.5KE18CA, SMCJ18CA-TR provides optimal balance of high-energy clamping (1500 W), low thermal resistance, and SMT manufacturability - making it preferred for new industrial and automotive designs requiring repeatable surge immunity.
Availability
SMCJ18CA-TR is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, RS-485 communication ports, and smart meter AC interfaces requiring stable component supply and long-term lifecycle support.
Supply support for SMCJ18CA-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 automotive ICs with strong manufacturing vertical integration.
This device belongs to ST's SMCJ series of high-power TVS diodes, engineered specifically for robust transient suppression in harsh industrial and automotive environments where reliability under thermal and electrical stress is critical.
FAQ
What is the maximum clamping voltage of SMCJ18CA-TR under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 29.2 V at 53 A for a 10/1000 µs waveform, measured at 25 °C ambient. At elevated junction temperatures (e.g., 125 °C), VCL increases by αT × (Tj − 25), where αT = 10⁻⁴/°C - resulting in ~30.2 V at 125 °C.
Can SMCJ18CA-TR be used in unidirectional configurations?
No - SMCJ18CA-TR is strictly bidirectional, indicated by the "CA" suffix. For unidirectional protection (e.g., DC rail to ground), use SMCJ18A-TR, which has asymmetric clamping and requires correct anode/cathode orientation relative to ground.
Does this TVS diode meet automotive AEC-Q200 requirements?
SMCJ18CA-TR is not AEC-Q200 qualified. While it operates up to 150 °C and meets IEC 61000-4-2/4-4, ST does not list it in their AEC-Q200-certified portfolio. For automotive-grade qualification, consider ST's Automotive TVS family such as SMAJ18CA-Q or SMF18CA-Q.
What is the recommended PCB footprint for SMCJ18CA-TR?
The JEDEC-standard SMC footprint requires pad dimensions of 5.11 mm × 1.54 mm per terminal, with 3.14 mm center-to-center spacing. ST recommends ≥2 cm² total copper area under each lead to achieve Rth(j-a) ≤ 45 °C/W and sustain 1500 W pulses without thermal runaway.
SMCJ18CA-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):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 39.3V
- Current - Peak Pulse (10/1000µs):
- 254A (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
SMCJ18CA-TR FAQ
1.How can I place an order for SMCJ18CA-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ18CA-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 SMCJ18CA-TR reliable?
The price and inventory of SMCJ18CA-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ18CA-TR is usually 5 days.
3.What payment methods are accepted for SMCJ18CA-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ18CA-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ18CA-TR?
SMCJ18CA-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ18CA-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 SMCJ18CA-TR?
For technical support, including SMCJ18CA-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ18CA-TR requirements.
6.How does Aetrix verify that SMCJ18CA-TR is sourced from the original manufacturer or authorized distributors?
All SMCJ18CA-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 SMCJ18CA-TR meets industry standards.
7.What is the process for return or replacement of SMCJ18CA-TR?
All SMCJ18CA-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ18CA-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 SMCJ18CA-TR part is unused and in its original packaging.
Return procedure for SMCJ18CA-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ18CA-TR Tags
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ESD9B5.0ST5G
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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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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