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STMicroelectronics SMA6J18CA-TR
- Part No.:
- SMA6J18CA-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMA6J18CA-TR.pdf
- Description:
- TVS DIODE 18VWM 33.2VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:10,848
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Product details
Overview
SMA6J18CA-TR from STMicroelectronics is a bidirectional 600 W transient voltage suppression diode with a standoff voltage of 18 V, clamping voltage of 28.3 V at 21.5 A (10/1000 µs), and operating junction temperature up to +175 °C. It protects sensitive I/O lines in industrial PLCs, automotive body control modules, and telecom power interfaces against IEC 61000-4-2 ESD (±30 kV contact/air) and IEC 61000-4-4 surge events.
For engineers reviewing the SMA6J18CA-TR datasheet, SMA6J18CA-TR pinout, SMA6J18CA-TR application, or SMA6J18CA-TR equivalent, key selection criteria include bidirectional clamping behavior, low leakage (<0.2 µA @ 25 °C), JEDEC DO-214AC (SMA) package compatibility, and thermal stability across -55 °C to +175 °C junction range.
Technical Context
This TVS diode employs planar silicon technology to achieve low dynamic resistance (9.2 Ω at 10/1000 µs), high surge robustness (600 W peak pulse power), and stable voltage clamping over temperature. Its bidirectional configuration enables symmetrical protection on AC-coupled or floating signal paths without polarity constraints.
Designed for IEC 61000-4-2 level 4 and IEC 61000-4-4 level 4 compliance, it delivers 30 kV ESD immunity and clamps transients within 1 ns response time. The device operates with minimal capacitance (≈100 pF at 1 V, bidirectional type), making it suitable for high-speed data lines up to ~100 Mbps.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 18 V - Maximum continuous reverse working voltage before conduction begins |
| Breakdown Voltage (VBR) | 20.0–22.1 V @ 1 mA - Ensures reliable triggering margin above 18 V nominal operation |
| Clamping Voltage (VCL) | 28.3 V @ 21.5 A (10/1000 µs) - Limits downstream voltage stress during surge events |
| Peak Pulse Power (PPP) | 600 W (10/1000 µs) - Sustains industrial-grade surge energy without failure |
| Leakage Current (IRM) | 0.2 µA @ 25 °C - Minimizes standby power loss and signal integrity impact |
| Junction Temperature Range | -55 °C to +175 °C - Enables deployment in under-hood automotive or high-temp industrial enclosures |
| ESD Withstand | ±30 kV (IEC 61000-4-2, contact & air) - Exceeds level 4 immunity requirements |
Pinout & Package
The SMA6J18CA-TR is housed in a JEDEC DO-214AC (SMA) surface-mount package with two terminals: Cathode (K) and Anode (A), configured as a bidirectional pair - no polarity marking required for symmetric clamping.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Transient current entry point (negative polarity event) | Conducts during negative surges; forms symmetrical clamp path with cathode |
| Cathode (K) | Transient current entry point (positive polarity event) | Conducts during positive surges; completes bidirectional clamping loop |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection on AC, differential, or floating bus lines without external polarity management |
| Low dynamic resistance (RD) | 9.2 Ω ensures minimal voltage overshoot during fast 10/1000 µs transients |
| High-temperature reliability | Rated for 175 °C junction operation - supports placement near power stages or in sealed enclosures |
| UL94 V0 resin housing | Meets flammability safety standard for industrial and automotive end-equipment certification |
| MSL Level 1 rating | Zero moisture sensitivity - safe for reflow without baking or special handling |
Applications
| Industrial PLC I/O Protection | Automotive Body Control Module |
|---|---|
Use Scenario: Protecting 24 V digital input channels in programmable logic controllers exposed to inductive load switching and field wiring surges. IC Role / Device Role / Timing Role: Bidirectional TVS diode placed at connector interface to clamp ±1 kV/40 Ω surge (IEC 61000-4-4) before signal conditioning circuitry. Use Value: Prevents latch-up or damage to optocoupler inputs and microcontroller GPIOs while maintaining <100 pF loading on 10 kHz–1 MHz input signals. | Use Scenario: Safeguarding LIN bus transceivers and sensor supply lines in door modules subject to battery dump and load-dump transients. IC Role / Device Role / Timing Role: Standoff-rated TVS on 12 V rail and LIN signal line to suppress >100 V/50 ms load-dump spikes per ISO 7637-2 pulse 5a. Use Value: Clamps voltage to ≤28.3 V within nanoseconds, preserving transceiver functionality and avoiding system reset during vehicle cranking or alternator regulation faults. |
| Telecom Power Interface | Smart Meter Communication Port |
Use Scenario: Shielding 48 V DC power input and RS-485 data lines in outdoor telecom equipment against lightning-induced surges. IC Role / Device Role / Timing Role: Primary-level TVS on power rail and secondary-level TVS on differential data lines to meet IEC 61000-4-5 (1 kV/2 Ω) requirements. Use Value: Delivers 600 W surge handling with <1 ns response, limiting voltage rise to safe levels for DC-DC converters and isolated transceivers without derating. | Use Scenario: Securing HPLC (G3-PLC) or RF mesh communication ports in utility meters installed in electrically noisy substations. IC Role / Device Role / Timing Role: Bidirectional TVS on AC-coupled signal paths to absorb ESD from hot-plug connectors and induced noise from nearby switching power supplies. Use Value: Maintains signal integrity below 100 pF capacitance while surviving repeated ±30 kV ESD strikes - critical for long-term field reliability and metrology certification. |
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-TR | Same 18 V VRM and bidirectional topology, but SMB package (DO-214AA) - 1.5× larger footprint, higher thermal mass | Lower power density; better suited for manual assembly or lower-volume boards where space permits | Select when board layout allows larger pad area and higher surge margin (600 W same, but longer thermal time constant) |
| 1.5KE18CA | Through-hole DO-15 package, 1500 W rating (10/1000 µs), higher clamping voltage (32.4 V) | Designed for primary-side AC/DC input protection, not signal-line use due to size and capacitance | Choose only for legacy through-hole designs requiring higher peak power, not for space-constrained PCBs or high-speed data lines |
Compared with SMBJ18CA-TR and 1.5KE18CA, SMA6J18CA-TR offers optimal balance of compact DO-214AC footprint, low capacitance, and precise 28.3 V clamping - making it preferred for modern high-density industrial and automotive PCBs where signal integrity and thermal cycling endurance are critical.
Availability
SMA6J18CA-TR is available at Aetrix Electronics and suitable for industrial PLC I/O protection, automotive body control modules, and telecom power interface designs requiring stable component supply, full traceability, and long-lifecycle support.
Supply support for SMA6J18CA-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, delivering intelligent power, analog, MEMS, and microcontroller solutions for industrial, automotive, and consumer markets.
The SMA6J series belongs to ST's transient protection portfolio, engineered specifically for high-reliability, high-temperature ESD and surge suppression in space-constrained, mission-critical applications.
FAQ
What is the difference between SMA6J18CA-TR and SMA6J18A-TR?
The "CA" suffix denotes bidirectional configuration, meaning it clamps both positive and negative transients symmetrically across its terminals. The "A" version is unidirectional - it conducts only when the cathode is more positive than the anode. This makes SMA6J18CA-TR ideal for AC-coupled, differential, or floating signal lines, whereas SMA6J18A-TR suits DC-biased rails like 12 V or 24 V power inputs.
Does SMA6J18CA-TR require a heatsink for 600 W surge handling?
No heatsink is required for single-event 600 W (10/1000 µs) surge handling, as energy dissipation occurs in microseconds and junction temperature rise remains within safe limits. However, sustained repetitive surges or high ambient temperatures (>105 °C) may necessitate PCB copper pour under the device per ST's recommended footprint (5.43 mm × 2.63 mm) to maintain Tj ≤ 175 °C.
Can SMA6J18CA-TR be used on USB 2.0 or CAN FD data lines?
No - its typical junction capacitance (~100 pF at 1 V) exceeds the <5 pF requirement for USB 2.0 full-speed signaling and introduces excessive signal distortion on CAN FD buses (>2 Mbps). It is appropriate for slower interfaces like RS-232, RS-485, LIN, or power rails, but not high-speed serial data lines.
Is SMA6J18CA-TR compliant with RoHS and REACH?
Yes - SMA6J18CA-TR is manufactured in ST's ECOPACK2-compliant facilities and meets RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006, including SVHC screening. Full compliance documentation, including material declarations and test reports, is available upon request from Aetrix Electronics or directly from ST's quality portal.
SMA6J18CA-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AC, SMA
- Series:
- SMA6J, 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:
- 33.2V
- Current - Peak Pulse (10/1000µs):
- 102A (8/20µs)
- Power - Peak Pulse:
- 600W
- 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:
- DO-214AC (SMA)
SMA6J18CA-TR FAQ
1.How can I place an order for SMA6J18CA-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA6J18CA-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 SMA6J18CA-TR reliable?
The price and inventory of SMA6J18CA-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA6J18CA-TR is usually 5 days.
3.What payment methods are accepted for SMA6J18CA-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA6J18CA-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA6J18CA-TR?
SMA6J18CA-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA6J18CA-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 SMA6J18CA-TR?
For technical support, including SMA6J18CA-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA6J18CA-TR requirements.
6.How does Aetrix verify that SMA6J18CA-TR is sourced from the original manufacturer or authorized distributors?
All SMA6J18CA-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 SMA6J18CA-TR meets industry standards.
7.What is the process for return or replacement of SMA6J18CA-TR?
All SMA6J18CA-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMA6J18CA-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 SMA6J18CA-TR part is unused and in its original packaging.
Return procedure for SMA6J18CA-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMA6J18CA-TR Tags
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