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STMicroelectronics SM15T12CA
- Part No.:
- SM15T12CA
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM15T12CA.pdf
- Description:
- TVS DIODE 10.2VWM 21.7VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:3,858
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Product details
Overview
SM15T12CA from STMicroelectronics is a bidirectional transient voltage suppression (TVS) diode in SMC package, designed for IEC 61000-4-2 ESD protection (±30 kV air/contact) and IEC 61000-4-4 surge immunity (4 kV level 4). It features a 12 V standoff voltage (VRM), 16.7 V clamping voltage at 461 A (8/20 µs), and 1500 W peak pulse power (10/1000 µs) at 25 °C - deployed in industrial power supplies and telecom interface circuits.
For engineers reviewing the SM15T12CA datasheet, SM15T12CA pinout, SM15T12CA application, or SM15T12CA equivalent, key selection criteria include bidirectional clamping behavior, low leakage (0.2 µA at 25 °C), high junction temperature capability (150 °C), and compatibility with FR4 PCB footprints per IPC7531.
Technical Context
The SM15T12CA operates as a planar-junction avalanche diode with symmetrical bidirectional breakdown, enabling protection of AC-coupled or differential signal lines without polarity constraints. Its dynamic resistance (RD = 0.020 Ω at 25 °C) ensures minimal voltage overshoot during fast transients.
Thermal performance is defined by junction-to-ambient thermal resistance (Rth(j-a)) down to ~40 °C/W with 4.5 cm² copper area per lead, supporting sustained operation at Tj = 150 °C where peak pulse power remains ≥1250 W (10/1000 µs).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 12 V - maximum continuous reverse working voltage before significant leakage begins |
| Breakdown Voltage (VBR) | 10.2–12.6 V at 1 mA - guaranteed avalanche onset range defining conduction threshold |
| Clamping Voltage (VCL) | 16.7 V at 461 A (8/20 µs) - peak voltage seen by protected circuit during worst-case surge |
| Peak Pulse Power (PPP) | 1500 W (10/1000 µs) - energy-handling capacity under standard lightning-surge waveform |
| Leakage Current (IRM) | 0.2 µA at VRM and 25 °C - negligible DC loading on high-impedance signal paths |
| Junction Temperature Range | −55 to +150 °C - enables deployment in extended-temperature industrial environments |
| ESD Withstand (IEC 61000-4-2) | ±30 kV contact & air discharge - exceeds level 4, eliminating need for external ESD staging |
Pinout & Package
SM15T12CA is housed in an SMC (DO-214AB) surface-mount package with two terminals: Cathode (K) and Anode (A), arranged symmetrically for bidirectional operation. The package complies with JEDEC MO-136AC and IPC7531 footprint standards, featuring matte tin-plated leads and MSL level 1 moisture sensitivity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Terminal 1 (cathode-marked end) | One side of symmetrical avalanche junction; connects to line under protection |
| Cathode (K) | Terminal 2 (opposite end) | Other side of symmetrical junction; ties to ground or reference plane |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC signals, RS-485 buses, and Ethernet PHY interfaces without polarity concerns |
| Low dynamic resistance (0.020 Ω) | Minimizes clamping voltage rise under high-current surges, preserving margin for downstream ICs |
| High-temperature derating support | Maintains 1250 W pulse capability at Tj = 150 °C - critical for enclosed power converters |
| UL 497B certified (QVGQ2.E136224) | Validates suitability for telecom and industrial secondary-circuit surge protection per safety standards |
| JEDEC-compliant SMC footprint | Ensures mechanical compatibility with automated assembly and thermal relief design rules on FR4 |
Applications
| Industrial Power Supply Input | RS-485 Data Line Protection |
|---|---|
|
Use Scenario: 24 V DC input stage of programmable logic controller (PLC) power module exposed to load dump and inductive switching transients. IC Role / Device Role / Timing Role: Bidirectional TVS device clamping both positive and negative polarity surges on unregulated rail. Use Value: Limits transient voltage to ≤16.7 V during 461 A 8/20 µs events, preventing damage to upstream rectifier and downstream DC-DC controller. |
Use Scenario: Termination point of long-haul RS-485 bus in factory automation network subject to ESD and lightning-induced coupling. IC Role / Device Role / Timing Role: Symmetrical overvoltage clamp across differential pair (A/B lines), referenced to local ground. Use Value: Absorbs ±30 kV ESD strikes without latch-up, maintaining signal integrity below 100 pF junction capacitance at 12 V bias. |
| Telecom DSL Line Interface | Smart Meter AC Mains Surge Protection |
|
Use Scenario: Protection of ADSL/VDSL line driver/receiver ICs connected to twisted-pair telephone lines. IC Role / Device Role / Timing Role: Primary-level surge suppressor placed between transformer secondary and PHY IC inputs. Use Value: Clamps induced surges up to 4 kV (IEC 61000-4-4 level 4) while adding <100 pF capacitance to preserve high-frequency signal fidelity. |
Use Scenario: Secondary-side transient suppression on 230 V AC metering front-end after isolation transformer and bridge rectifier. IC Role / Device Role / Timing Role: Fast-response bidirectional clamp on DC bus derived from rectified mains, before metering ADC. Use Value: Survives repeated 1500 W surges at elevated ambient temperatures (up to 85 °C enclosure), ensuring 10+ year field reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ12CA (Bourns) | Same 12 V VRM, but lower PPP = 600 W (10/1000 µs); higher VCL = 19.9 V at 30.1 A | Limited to lower-energy surge environments; unsuitable for 1500 W lightning test compliance | Select when cost sensitivity outweighs peak surge requirement and board space allows larger footprint |
| P6SMB12CA (ON Semiconductor) | Identical SMC package and 12 V rating, but IRM = 1 µA (5× higher leakage) and VCL = 19.2 V at 31.2 A | Higher leakage may affect precision sensor bias networks; reduced clamping margin vs. protected IC VDS(max) | Prefer only if legacy BOM alignment or dual-sourcing mandates ON's qualification pedigree |
Compared with SMBJ12CA and P6SMB12CA, SM15T12CA delivers superior surge robustness (1500 W), tighter clamping (16.7 V), and ultra-low leakage (0.2 µA), making it optimal for high-reliability industrial and telecom systems requiring full IEC 61000-4-4 level 4 compliance.
Availability
SM15T12CA is available at Aetrix Electronics and suitable for industrial power supply input stages, RS-485 data line protection, telecom DSL line interfaces, and smart meter AC mains surge protection requiring stable component supply and long-term lifecycle assurance.
Supply support for SM15T12CA 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 automotive, industrial, and power discrete solutions with vertical manufacturing and broad IP portfolio.
SM15T12CA belongs to ST's high-power planar TVS diode product line, engineered specifically for robust, low-leakage transient protection in harsh industrial and telecom environments where thermal stability and ESD immunity are mission-critical.
FAQ
What is the difference between SM15T12A and SM15T12CA?
SM15T12A is unidirectional (anode-cathode asymmetry), intended for DC-biased lines like power rails; SM15T12CA is bidirectional (symmetrical breakdown), used for AC-coupled or differential signals such as RS-485 or Ethernet. Their marking codes differ (MDT vs. BDT), and CA type shows no polarity band.
Can SM15T12CA be used in parallel for higher surge current handling?
No - paralleling TVS diodes causes current imbalance due to VBR tolerance (±10%), leading to premature failure of the lower-breakdown unit. For >461 A surge capability, select a higher-rated part like SM15T15CA or use staged protection with MOV + TVS.
Does SM15T12CA require a heatsink for 1500 W pulse dissipation?
No - the 1500 W rating applies to a single 10/1000 µs pulse at Tj = 25 °C. Thermal design focuses on PCB copper area (≥4.5 cm² per lead) and reflow profile adherence; no external heatsink is needed for typical surge duty cycles.
Is SM15T12CA compliant with RoHS and REACH?
Yes - SM15T12CA carries ST's ECOPACK2 environmental grade certification, meeting RoHS Directive 2011/65/EU and REACH SVHC thresholds. Lead finish is matte tin, and packaging complies with J-STD-020 MSL level 1.
SM15T12CA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- SM15T, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 10.2V
- Voltage - Breakdown (Min):
- 11.4V
- Voltage - Clamping (Max) @ Ipp:
- 21.7V
- Current - Peak Pulse (10/1000µs):
- 461A (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
SM15T12CA FAQ
1.How can I place an order for SM15T12CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SM15T12CA 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 SM15T12CA reliable?
The price and inventory of SM15T12CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM15T12CA is usually 5 days.
3.What payment methods are accepted for SM15T12CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM15T12CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM15T12CA?
SM15T12CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM15T12CA 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 SM15T12CA?
For technical support, including SM15T12CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM15T12CA requirements.
6.How does Aetrix verify that SM15T12CA is sourced from the original manufacturer or authorized distributors?
All SM15T12CA 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 SM15T12CA meets industry standards.
7.What is the process for return or replacement of SM15T12CA?
All SM15T12CA units undergo pre-shipment inspection (PSI). If there is an issue with SM15T12CA, 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 SM15T12CA part is unused and in its original packaging.
Return procedure for SM15T12CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM15T12CA Tags
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