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STMicroelectronics SM15T12AY
- Part No.:
- SM15T12AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM15T12AY.pdf
- Description:
- TVS DIODE 10.2VWM 21.7VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:2,162
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Product details
Overview
SM15T12AY from STMicroelectronics is an AEC-Q101-qualified unidirectional automotive TVS diode in SMC package, designed to clamp transient surges up to 16.7 A (10/1000 µs) with 12 V breakdown voltage (VBR = 10.2–12.6 V), 16.7 V clamping voltage (VCL) at rated current, and 1500 W peak pulse power. It protects 12 V automotive power nets against ISO 7637-2 Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V), as well as ESD per ISO 10605 (±30 kV air/contact).
For engineers reviewing the SM15T12AY datasheet, SM15T12AY pinout, SM15T12AY application, or SM15T12AY equivalent, key selection criteria include its 12 V stand-off rating, 0.2 µA leakage at 25 °C, 150 °C max junction temperature, low dynamic resistance (0.046 Ω), and compliance with automotive surge and ESD immunity standards.
Technical Context
This unidirectional TVS operates as a voltage-clamping protection device across DC power rails, triggered when reverse voltage exceeds its 12 V nominal breakdown threshold. Its planar silicon junction enables stable leakage performance (<1 µA up to 85 °C) and high thermal robustness (Tj max = 150 °C), critical for under-hood automotive modules.
The device delivers 1500 W peak pulse power (10/1000 µs) at 25 °C ambient and retains 1250 W capability at Tj = 150 °C. Its dynamic resistance of 0.046 Ω ensures tight clamping during fast transients, while IEC 61000-4-4 Level 4 (4 kV) and ISO 10605 (±30 kV) compliance confirms suitability for harsh vehicle environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 10.2 / 11.4 / 12.6 V - Ensures reliable turn-on above 12 V system nominal without false triggering during load dump overshoot. |
| VCL @ IPP = 16.7 A | 16.7 V - Clamps 12 V rail transients to safe levels below downstream IC absolute maximum ratings. |
| IPP (10/1000 µs) | 16.7 A - Withstands ISO 7637-2 Pulse 1 (−150 V) on 12 V battery systems with typical line impedance. |
| RD (dynamic resistance) | 0.046 Ω - Minimizes voltage overshoot during high-current surges, improving protection margin. |
| IR @ VRM = 12 V | 0.2 µA at 25 °C - Enables low-power always-on monitoring circuits without leakage-induced errors. |
| Tj max | 150 °C - Supports placement near heat sources (e.g., engine control units) without derating loss. |
| Package | SMC (DO-214AB) - Industry-standard surface-mount outline with IPC7531 footprint and JEDEC registration. |
Pinout & Package
SM15T12AY uses the SMC (DO-214AB) package: 2-terminal unidirectional configuration with cathode marked by band. Dimensions: L = 5.55–6.25 mm, W = 7.75–8.15 mm, H = 2.45 mm max. Matte tin-plated leads meet J-STD-002 and MIL-STD-750 solderability requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | DC power rail return path | Connected to ground or low-side reference; completes clamping path during negative transients (e.g., ISO 7637-2 Pulse 1). |
| Cathode | Protected line input | Connected to 12 V supply rail; blocks forward current but conducts reverse surge current to shunt energy to ground. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood use with extended temperature cycling, humidity, and mechanical shock testing. |
| Low leakage current | 0.2 µA at 25 °C and 1 µA at 85 °C - preserves battery life in always-on vehicle subsystems (e.g., CAN wake-up receivers). |
| High-temperature operation | Full 1500 W surge rating maintained up to Tj = 150 °C - eliminates need for thermal derating in compact ECUs. |
| ISO 7637-2 compliance | Withstands Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), Pulse 3b (+150 V) - covers all major automotive power-line transients. |
| ESD immunity | ±30 kV contact/air discharge (ISO 10605, C = 330 pF/R = 330 Ω) - exceeds automotive infotainment and sensor interface requirements. |
Applications
| Engine Control Unit (ECU) Power Input | Body Control Module (BCM) LIN Bus Protection |
|---|---|
|
Use Scenario: 12 V battery feed to microcontroller power domain exposed to load dump and alternator ripple. IC Role / Device Role / Timing Role: Primary overvoltage clamp on main VCC rail, activated within nanoseconds of surge onset. Use Value: Limits transient voltage to ≤16.7 V, preventing latch-up or permanent damage to 3.3 V/5 V regulators and MCU IO cells. |
Use Scenario: LIN physical layer transceiver powered from switched 12 V supply in door module or seat controller. IC Role / Device Role / Timing Role: Secondary protection stage upstream of integrated LIN transceiver ESD diodes. Use Value: Absorbs ISO 7637-2 Pulse 3b (+150 V) before it reaches transceiver's internal 40 V clamp, extending reliability. |
| Automotive Camera Power Supply | Telematics Unit GPS Antenna Bias Line |
|
Use Scenario: 12 V input to DC-DC converter powering image sensor and ISP in rear-view camera. IC Role / Device Role / Timing Role: First-line defense against ignition noise and cable harness coupling events. Use Value: Maintains <0.2 µA leakage to avoid bias current error in precision current-sense circuits feeding the converter. |
Use Scenario: +5 V bias line feeding active GPS antenna via coaxial cable in telematics control unit. IC Role / Device Role / Timing Role: Low-capacitance transient suppressor placed between bias regulator and RF connector. Use Value: Clamps ESD events (±30 kV) without degrading RF signal integrity due to planar junction's controlled capacitance profile. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional automotive TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12A | Lower peak power (400 W), higher VCL (19.9 V), non-AEC-Q101 qualified | Limited to non-automotive industrial or consumer 12 V rails without ISO 7637-2 compliance | Select only if cost sensitivity outweighs automotive qualification and surge margin requirements. |
| 1.5SMC12A | Same SMC package, 1500 W rating, but no AEC-Q101 validation; VCL = 19.9 V at 16.7 A | Acceptable for commercial-grade automotive accessories (e.g., aftermarket dashcams) lacking OEM certification | Choose when full AEC-Q101 traceability is not required and higher clamping voltage is tolerable. |
Compared with SMAJ12A and 1.5SMC12A, SM15T12AY provides superior automotive readiness through AEC-Q101 qualification, lower clamping voltage (16.7 V vs. ≥19.9 V), and guaranteed ISO 7637-2 Pulse 1–3b immunity-critical for OEM ECU designs where failure modes must be rigorously controlled.
Availability
SM15T12AY is available at Aetrix Electronics and suitable for engine control units, body control modules, automotive camera power supplies, and telematics GPS bias lines requiring stable component supply with full automotive qualification and traceable sourcing.
Supply support for SM15T12AY 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 automotive, industrial, and power discrete solutions with vertical manufacturing and long-term product longevity commitments.
SM15T12AY belongs to ST's automotive-grade TVS portfolio designed specifically for ISO 7637-2 and ISO 10605-compliant protection of 12 V power networks in engine, chassis, and infotainment systems.
FAQ
What is the maximum clamping voltage of SM15T12AY under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 16.7 V at peak pulse current IPP = 16.7 A for a 10/1000 µs waveform, measured at Tamb = 25 °C. This value increases linearly with junction temperature using αT = 7.8 × 10−4/°C, reaching ~17.5 V at Tj = 150 °C.
Is SM15T12AY compatible with lead-free reflow soldering processes?
Yes-SM15T12AY features matte tin-plated leads qualified to J-STD-020 MSL level 1 and supports ST's recommended reflow profile: peak temperature 240–245 °C for ≤60 seconds, with ramp rates ≤3 °C/s. It meets IPC/JEDEC J-STD-020 revision G requirements.
How does SM15T12AY differ from the bidirectional SM15T12CAY variant?
SM15T12AY is unidirectional (anode-to-cathode blocking), intended for DC power rail protection where polarity is fixed. SM15T12CAY is bidirectional (symmetrical breakdown), used in AC-coupled or polarity-agnostic signal lines like LIN or CAN. Their VBR, VCL, and surge ratings are identical, but circuit placement and grounding differ.
Can SM15T12AY protect against ISO 7637-2 Pulse 1 on a 24 V system?
No-SM15T12AY is rated for 12 V nominal systems. Its 12 V VBR and 16.7 V VCL are insufficient to withstand −150 V Pulse 1 on 24 V rails without catastrophic failure. For 24 V systems, use SM15T24AY (VBR = 20.5–25.2 V, VCL = 33.2 V).
SM15T12AY 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:
- 1
- Bidirectional Channels:
- -
- 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
SM15T12AY FAQ
1.How can I place an order for SM15T12AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM15T12AY 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 SM15T12AY reliable?
The price and inventory of SM15T12AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM15T12AY is usually 5 days.
3.What payment methods are accepted for SM15T12AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM15T12AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM15T12AY?
SM15T12AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM15T12AY 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 SM15T12AY?
For technical support, including SM15T12AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM15T12AY requirements.
6.How does Aetrix verify that SM15T12AY is sourced from the original manufacturer or authorized distributors?
All SM15T12AY 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 SM15T12AY meets industry standards.
7.What is the process for return or replacement of SM15T12AY?
All SM15T12AY units undergo pre-shipment inspection (PSI). If there is an issue with SM15T12AY, 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 SM15T12AY part is unused and in its original packaging.
Return procedure for SM15T12AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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