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STMicroelectronics SM50T12AY
- Part No.:
- SM50T12AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM50T12AY.pdf
- Description:
- AUTOMOTIVE 5000 W, 10 V TVS IN S
- Quantity:
- Payment:
- Shipping:
Inventory:2,500
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Product details
Overview
SM50T12AY from STMicroelectronics is an AEC-Q101-qualified unidirectional automotive TVS diode in SMC package, designed to clamp transients up to 5000 W (10/1000 µs) with a 12 V nominal breakdown voltage (VBR = 11.1–12.3 V), 17 A peak pulse current (IPP), and 15.9 V clamping voltage (VCL) at 25 °C - deployed in 12 V battery rail protection for e-breaker modules compliant with ISO 7637-2 Pulse 1/2a/3a/3b and ISO 16750.
For engineers reviewing the SM50T12AY datasheet, SM50T12AY pinout, SM50T12AY application, or SM50T12AY equivalent, key selection criteria include its 175 °C junction temperature rating, 0.2 µA leakage at 25 °C, 295 mΩ dynamic resistance, and SMC package compatibility with high-reliability automotive PCB layouts requiring IEC 61000-4-2 ±30 kV ESD immunity.
Technical Context
This unidirectional TVS diode uses planar silicon technology to achieve low leakage (0.2 µA @ 25 °C) and stable VBR drift (αT = 10 × 10−4/°C) across −55 °C to +175 °C operating range. Its clamping behavior follows VCL = VBR(max) + RD × IPP, enabling predictable overvoltage suppression during load dump and ISO 7637-2 pulses.
The device meets stringent automotive surge standards: IEC 61000-4-4 Level 4 (4 kV), ISO 10605 ±30 kV (330 pF/330 Ω), and ISO 7637-2 Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V), with no derating required below 125 °C junction temperature per Figure 3.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 11.1 / 11.7 / 12.3 V - ensures reliable triggering above 12 V system nominal while avoiding false trips during cold-cranking dips. |
| VCL @ IPP = 17 A | 15.9 V - limits downstream IC voltage stress during 10/1000 µs surges on 12 V power rails. |
| IPP (10/1000 µs) | 17 A - supports robust protection against ISO 7637-2 Pulse 1 (−150 V) with 5000 W peak power dissipation. |
| RD (dynamic resistance) | 295 mΩ - determines VCL rise slope under transient current, critical for maintaining safe clamping margin. |
| IR @ VRM = 10 V | 0.2 µA - enables low standby power loss in always-on automotive modules such as body control units. |
| Tj(max) | 175 °C - allows operation in engine bay environments without thermal derating up to ambient 125 °C. |
| Package | SMC (DO-214AB) - JEDEC-registered outline with 7.75–8.15 mm width, compatible with standard automotive reflow profiles (J-STD-020 MSL 1). |
Pinout & Package
SM50T12AY is housed in an SMC (DO-214AB) surface-mount package with cathode-bar marked polarity. The device has two terminals: anode and cathode - configured for unidirectional clamping from cathode to anode.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference node | Connected to ground or low-impedance return path; defines reverse-biased operation during positive transients. |
| Cathode | Protected line input | Connected to 12 V supply rail; conducts surge current to ground when VIN exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood use with 1000-cycle temperature cycling, mechanical shock, and humidity testing. |
| Planar silicon construction | Enables <0.2 µA leakage at 25 °C and stable VBR drift over lifetime, critical for long-term reliability in e-fuse applications. |
| ISO 7637-2 Pulse 1/2a/3a/3b compliance | Clamps −150 V (Pulse 1), +112 V (Pulse 2a), −220 V (Pulse 3a), and +150 V (Pulse 3b) without failure or parameter shift. |
| IEC 61000-4-2 ±30 kV ESD immunity | Withstands contact and air discharge at full level 4 without degradation - eliminates need for secondary ESD stages. |
| JEDEC-registered SMC footprint | Ensures mechanical compatibility with automated assembly lines and IPC-7531-compliant PCB land patterns. |
Applications
| Engine Control Unit (ECU) Power Input | e-Fuse / Electronic Circuit Breaker |
|---|---|
|
Use Scenario: Protects microcontroller and CAN transceiver power inputs from load dump and alternator-induced surges in gasoline/diesel ECUs. IC Role / Device Role: Primary transient voltage suppressor placed directly at 12 V input connector before DC-DC converter. Use Value: Clamps 150 V ISO 7637-2 Pulse 1 to ≤15.9 V within 1 ns, preventing latch-up or permanent damage to downstream 5 V/3.3 V regulators. |
Use Scenario: Integrated into solid-state relay modules that replace mechanical fuses in battery management systems. IC Role / Device Role: Overvoltage guard for MOSFET gate drivers during fault conditions like short-circuit-induced bus spikes. Use Value: Enables fail-safe shutdown by limiting gate-source voltage excursion to <16 V, preserving driver integrity during 17 A transient events. |
| Body Control Module (BCM) LIN Bus Protection | ADAS Camera Power Rail |
|
Use Scenario: Shields LIN transceivers and microcontrollers from coupled noise and battery reversal events in door modules and lighting controllers. IC Role / Device Role: Unidirectional TVS on 12 V supply line feeding LIN PHY, placed upstream of local LDO. Use Value: Maintains <0.2 µA leakage to avoid quiescent current violation in sleep mode while suppressing 30 kV ESD per ISO 10605. |
Use Scenario: Secures 12 V input to image sensor power supplies in forward-facing ADAS cameras exposed to engine bay thermal and electrical stress. IC Role / Device Role: First-line defense against ISO 7637-2 Pulse 3b (+150 V) induced by ignition switching near camera harnesses. Use Value: Limits clamped voltage to 15.9 V at 17 A, ensuring uninterrupted operation of 12 V-to-2.8 V buck converters powering CMOS image sensors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12A | Lower PPP (400 W), higher VCL (20.1 V @ 19.9 A), SMC package, non-AEC-Q101 rated | Limited to non-automotive industrial use; insufficient for ISO 7637-2 Pulse 1 (−150 V) without series impedance | Select only for cost-sensitive consumer-grade 12 V protection where AEC-Q101 and 5000 W capability are not required. |
| 1.5KE12A | Higher VCL (19.9 V @ 25.2 A), DO-201 package, 1500 W PPP, non-AEC-Q101 | Through-hole mounting incompatible with high-density automotive PCBs; lacks planar leakage performance | Use only in legacy through-hole designs where rework to SMD is impractical and thermal derating is acceptable. |
Compared with SMAJ12A and 1.5KE12A, SM50T12AY delivers 12.5× higher peak pulse power, 25% lower clamping voltage, AEC-Q101 qualification, and SMC packaging - making it the sole choice for modern automotive 12 V rail protection demanding ISO 7637-2 compliance and 175 °C operation.
Availability
SM50T12AY is available at Aetrix Electronics and suitable for engine control units, electronic circuit breakers, body control modules, and ADAS camera power systems requiring stable component supply across automotive production lifecycles.
Supply support for SM50T12AY 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 technologies with vertical manufacturing capabilities.
SM50T12AY belongs to the SM50TY series - a family of AEC-Q101-qualified 5000 W TVS diodes engineered specifically for ISO 7637-2 and ISO 16750-compliant automotive power rail protection in harsh under-hood environments.
FAQ
What is the maximum clamping voltage of SM50T12AY at 17 A?
The maximum clamping voltage (VCL) of SM50T12AY is 15.9 V at 25 °C for a 10/1000 µs waveform with 17 A peak pulse current. This value increases linearly with junction temperature due to the 10 × 10−4/°C temperature coefficient (αT), reaching approximately 17.2 V at 150 °C junction temperature.
Is SM50T12AY suitable for bidirectional transient suppression?
No - SM50T12AY is a unidirectional TVS diode, intended for clamping positive transients on DC power rails. For bidirectional protection (e.g., data lines or AC-coupled signals), ST offers the complementary SM50T12CAY variant, which features symmetrical breakdown in both polarities and identical surge ratings.
How does SM50T12AY differ from standard SMAJ12A in automotive use?
SM50T12AY provides 5000 W peak pulse power (vs. 400 W for SMAJ12A), AEC-Q101 qualification, 175 °C Tj(max), and 0.2 µA leakage - enabling direct integration into engine bay ECUs. SMAJ12A lacks automotive qualification, has higher clamping voltage (20.1 V), and cannot withstand ISO 7637-2 Pulse 1 without external impedance limiting.
What PCB layout recommendations apply to SM50T12AY?
Use the IPC-7531-compliant SMC footprint with 3.14 mm pad width, 5.11 mm pad length, and 8.19 mm center-to-center spacing. Minimize trace inductance by placing the device within 5 mm of the protected connector, and connect cathode directly to a low-impedance ground plane using ≥2 thermal vias per pad to maintain Rth(j-a) ≤ 45 °C/W per Figure 12.
SM50T12AY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 10V (Max)
- Voltage - Breakdown (Min):
- 11.1V
- Voltage - Clamping (Max) @ Ipp:
- 17V
- Current - Peak Pulse (10/1000µs):
- 295A
- Power - Peak Pulse:
- 5000W (5kW)
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMC
SM50T12AY FAQ
1.How can I place an order for SM50T12AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM50T12AY 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 SM50T12AY reliable?
The price and inventory of SM50T12AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM50T12AY is usually 5 days.
3.What payment methods are accepted for SM50T12AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM50T12AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM50T12AY?
SM50T12AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM50T12AY 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 SM50T12AY?
For technical support, including SM50T12AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM50T12AY requirements.
6.How does Aetrix verify that SM50T12AY is sourced from the original manufacturer or authorized distributors?
All SM50T12AY 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 SM50T12AY meets industry standards.
7.What is the process for return or replacement of SM50T12AY?
All SM50T12AY units undergo pre-shipment inspection (PSI). If there is an issue with SM50T12AY, 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 SM50T12AY part is unused and in its original packaging.
Return procedure for SM50T12AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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