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STMicroelectronics SM15T12CAY
- Part No.:
- SM15T12CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM15T12CAY.pdf
- Description:
- TVS DIODE 10.2VWM 21.7VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:2,297
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Product details
Overview
SM15T12CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppressor (TVS) diode in SMC package, designed for ISO 7637-2 pulse protection in 12 V battery systems. It features 12 V nominal breakdown voltage (VBR = 10.2–12.6 V), 16.7 A peak pulse current (IPP) at 10/1000 µs, 21.7 A at 8/20 µs, clamping voltage ≤21.7 V, and leakage current ≤0.2 µA at 25 °C - deployed in engine control units and body electronics to absorb load dump and ESD transients.
For engineers reviewing the SM15T12CAY datasheet, SM15T12CAY pinout, SM15T12CAY application, or SM15T12CAY equivalent, key selection criteria include bidirectional surge capability per ISO 10605 (±30 kV contact/air), junction temperature rating up to +150 °C, low dynamic resistance (0.046 Ω), and compliance with AEC-Q101 for under-hood reliability.
Technical Context
This TVS operates as a voltage-clamped shunt protector: during overvoltage events (e.g., ISO 7637-2 Pulse 1: −150 V, Pulse 3a: −220 V), it avalanches at VBR ≥10.2 V and clamps to ≤21.7 V at 16.7 A, limiting energy dissipation via planar silicon junction. Its bidirectional symmetry enables protection of AC-coupled or differential signal lines without polarity constraints.
Thermal performance is defined by Tjmax = +150 °C and power derating to 1250 W at Tj = +150 °C (10/1000 µs), supported by low thermal resistance (Rth(j-a) ≈ 100 °C/W on recommended FR4 footprint). Dynamic resistance (RD = 0.046 Ω) ensures minimal voltage overshoot during fast transients like ESD (IEC 61000-4-2).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 10.2 / 11.4 / 12.0 V - defines minimum avalanche initiation threshold across temperature; ensures reliable turn-on before downstream IC damage. |
| VCL @ IPP | 21.7 V at 8/20 µs - maximum clamped voltage seen by protected circuit during worst-case surge; guarantees safe margin below 24 V system tolerance. |
| IPP (8/20 µs) | 21.7 A - peak surge current handled without degradation; supports ISO 10605 ±30 kV ESD testing with C=150 pF/R=330 Ω. |
| RD | 0.046 Ω - dynamic resistance determining voltage rise per ampere of surge current; enables tight clamping under high di/dt. |
| IR @ VRM | 0.2 µA at 25 °C - ultra-low reverse leakage preserves signal integrity in high-impedance sensor interfaces and reduces standby power loss. |
| Tjmax | +150 °C - extended junction temperature rating allows placement near heat sources (e.g., power modules) in automotive ECUs. |
| Package | SMC (DO-214AB) - industry-standard surface-mount outline (7.75 × 5.55 mm) with IPC-7531-compliant footprint and matte tin leads. |
Pinout & Package
SM15T12CAY uses the SMC (DO-214AB) package: a 2-terminal surface-mount device with cathode band marking (BDTY) and symmetrical bidirectional terminals. No polarity distinction - both terminals function identically for surge conduction in either direction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Terminal 1 | Anode/Cathode (bidirectional) | Identical terminal for symmetric surge conduction; connects to protected line (e.g., LIN bus, CAN shield, or sensor supply). |
| Terminal 2 | Anode/Cathode (bidirectional) | Paired terminal completing the bidirectional path; ties to ground or reference plane to shunt transient energy. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood use including temperature cycling, humidity, and mechanical shock per JESD22 standards. |
| ISO 10605 ESD robustness | Withstands ±30 kV air/contact discharge (C = 150 pF/R = 330 Ω and C = 330 pF/R = 330 Ω), exceeding Level 4 requirements. |
| ISO 7637-2 surge immunity | Rated for Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V) in 12 V systems. |
| Low dynamic resistance | 0.046 Ω minimizes clamping voltage overshoot during fast 8/20 µs transients, critical for protecting high-speed digital interfaces. |
| High-temperature stability | Operates reliably up to +150 °C junction temperature with <5.7×10−4/°C VBR tempco, ensuring consistent clamping across engine bay conditions. |
Applications
| Engine Control Unit (ECU) Power Input | LIN Bus Transceiver Protection |
|---|---|
|
Use Scenario: Protecting 12 V supply rail of diesel/gasoline engine control units against load dump (ISO 7637-2 Pulse 1) and alternator ripple. IC Role / Device Role / Timing Role: Bidirectional shunt clamp absorbing up to −150 V negative transients while maintaining <21.7 V clamping during 21.7 A surges. Use Value: Prevents latch-up or permanent damage to MCU power management ICs and analog front-ends operating at 5 V or 3.3 V rails. |
Use Scenario: Safeguarding LIN transceivers (e.g., TLE7259) connected to vehicle body networks exposed to ESD and battery disconnection spikes. IC Role / Device Role / Timing Role: Fast-response bidirectional clamp placed between LIN line and ground, conducting within nanoseconds of transient onset. Use Value: Maintains LIN signal integrity (20 kbps) by limiting voltage excursions to <21.7 V, avoiding false dominant states or receiver saturation. |
| Automotive Camera Module Power Rail | Body Control Module (BCM) Sensor Inputs |
|
Use Scenario: Shielding 12 V input of rear-view or surround-view camera modules from ignition noise and jump-start surges. IC Role / Device Role / Timing Role: Primary overvoltage suppression element upstream of DC/DC converter, rated for continuous 1500 W (10/1000 µs) pulses. Use Value: Enables uninterrupted video streaming by preventing brownout or reset events caused by >100 V transients on camera power lines. |
Use Scenario: Protecting analog inputs (e.g., temperature, humidity, rain sensors) in BCMs from ESD coupling through long harnesses. IC Role / Device Role / Timing Role: Low-leakage (0.2 µA) bidirectional clamp placed at connector entry point, minimizing offset error in precision ADC measurements. Use Value: Preserves sensor accuracy (<0.1% FS error) while surviving ±30 kV ESD events without parameter drift or parametric shift. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12CA | Lower peak pulse power (400 W vs. 1500 W), higher VCL (23.2 V), same SMC package but not AEC-Q101 qualified. | Restricted to non-automotive industrial or consumer applications; insufficient for ISO 7637-2 Pulse 1/3a compliance. | Select only for cost-sensitive non-automotive designs where 1500 W surge immunity is unnecessary. |
| SMBJ12CA | Intermediate power rating (600 W), VCL = 21.2 V, AEC-Q101 qualified but lower IPP (19.9 A at 8/20 µs) and higher RD (0.052 Ω). | Suitable for less severe surge environments (e.g., interior modules), but marginal for under-hood ECU use per ISO 7637-2 Pulse 3a. | Choose when board space permits larger SMB package and full 1500 W headroom is not required. |
Compared with SMAJ12CA and SMBJ12CA, SM15T12CAY delivers 2.5× higher surge power handling, tighter clamping (21.7 V vs. 23.2 V), and verified AEC-Q101 stress performance - making it the only option qualified for primary protection in 12 V automotive power domains.
Availability
SM15T12CAY is available at Aetrix Electronics and suitable for engine control units, LIN bus nodes, automotive camera modules, and body control module sensor interfaces requiring stable component supply across automotive production lifecycles.
Supply support for SM15T12CAY 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 management solutions with vertical manufacturing and broad IP portfolio.
The SM15Txx series targets automotive transient protection, engineered specifically to meet ISO 7637-2, ISO 10605, and AEC-Q101 requirements for under-hood and chassis-mounted electronics.
FAQ
What is the difference between SM15T12AY and SM15T12CAY?
SM15T12AY is unidirectional (anode-to-cathode conduction only), while SM15T12CAY is bidirectional - enabling symmetric clamping for AC-coupled lines like LIN or differential sensor pairs. Both share identical VBR, VCL, and surge ratings, but CAY type has no polarity marking and conducts in both directions.
Does SM15T12CAY require heatsinking for 1500 W pulse handling?
No external heatsink is needed for single-pulse operation: the SMC package and recommended PCB footprint (8.19 × 5.11 mm copper area) provide sufficient thermal mass and conduction to dissipate 1500 W over 10/1000 µs without exceeding Tjmax = +150 °C, per Figure 11 in DS6928.
Can SM15T12CAY be used in 24 V truck systems?
No - SM15T12CAY is specified for 12 V battery systems only. Its 12 V VBR and 21.7 V VCL are too low for 24 V nominal rails; use SM15T24CAY (VBR = 20.5–25.2 V) instead to avoid premature conduction during normal operation.
How does the 0.046 Ω dynamic resistance affect system-level protection?
This low RD limits voltage overshoot during fast 8/20 µs transients: for a 21.7 A surge, only 1.0 V additional drop occurs beyond VBR, keeping total clamping at 21.7 V. This prevents false triggering of downstream overvoltage detectors and maintains timing margins in high-speed interfaces.
SM15T12CAY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- SM15TY, 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:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMC
SM15T12CAY FAQ
1.How can I place an order for SM15T12CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM15T12CAY 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 SM15T12CAY reliable?
The price and inventory of SM15T12CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM15T12CAY is usually 5 days.
3.What payment methods are accepted for SM15T12CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM15T12CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM15T12CAY?
SM15T12CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM15T12CAY 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 SM15T12CAY?
For technical support, including SM15T12CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM15T12CAY requirements.
6.How does Aetrix verify that SM15T12CAY is sourced from the original manufacturer or authorized distributors?
All SM15T12CAY 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 SM15T12CAY meets industry standards.
7.What is the process for return or replacement of SM15T12CAY?
All SM15T12CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM15T12CAY, 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 SM15T12CAY part is unused and in its original packaging.
Return procedure for SM15T12CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM15T12CAY Tags
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