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STMicroelectronics SM30T15CAY
- Part No.:
- SM30T15CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM30T15CAY.pdf
- Description:
- TVS DIODE 13VWM 21.5VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:831
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Product details
Overview
SM30T15CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppression (TVS) diode in SMC package, designed for ISO 7637-2 pulse protection and IEC/ISO ESD robustness. It features 15 V breakdown voltage (VBR = 14.2–15.8 V), 21.5 V clamping voltage (VCL) at 140 A (10/1000 µs), 3000 W peak pulse power, 0.2 µA leakage at 25 °C, and 175 °C maximum junction temperature - deployed in 12 V battery rail protection for engine control units and body electronics.
For engineers reviewing the SM30T15CAY datasheet, SM30T15CAY pinout, SM30T15CAY application, or SM30T15CAY equivalent, key selection criteria include bidirectional surge clamping capability, ISO 7637-2 Pulse 1/2a/3a/3b compliance, low dynamic resistance (11.5 mΩ), and AEC-Q101 qualification for under-hood deployment.
Technical Context
This bidirectional TVS uses planar silicon technology to achieve stable VBR temperature coefficient (αT = 10 × 10−4/°C) and low leakage across −55 °C to +175 °C operating range. Its symmetrical avalanche structure enables equal clamping in both polarities, critical for protecting differential bus lines like LIN or sensor interfaces against reverse-polarity transients and load dump coupling.
The device meets stringent automotive immunity requirements: ±30 kV ESD (ISO 10605, 150 pF/330 Ω), 4 kV EFT (IEC 61000-4-4 Level 4), and full ISO 7637-2 compliance including Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V) - all validated with Tj up to 175 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 14.2 / 15.0 / 15.8 V - Ensures reliable turn-on before downstream IC damage during 12 V system overvoltage events |
| VCL @ 140 A (10/1000 µs) | 21.5 V - Limits voltage seen by protected circuit during worst-case ISO 7637-2 Pulse 1 (−150 V) |
| IPP (10/1000 µs) | 140 A - Supports 3000 W surge dissipation without thermal runaway at Tj ≤ 175 °C |
| RD (dynamic resistance) | 11.5 mΩ - Minimizes clamping voltage rise under high-current transients, improving protection margin |
| IR @ VRM = 13 V | 0.2 µA at 25 °C - Prevents signal distortion and power loss in always-on automotive modules |
| Tjmax | +175 °C - Enables placement near heat sources (e.g., powertrain ECUs) without derating |
| AEC-Q101 qualified | Validated for automotive use per stress test conditions including HTOL, TC, UHAST, and ESD HBM/MM |
Pinout & Package
SM30T15CAY is housed in an industry-standard SMC (DO-214AB) surface-mount package with JEDEC registered outline, matte tin lead finish, and IPC7531-compliant footprint. The bidirectional configuration has no polarity marking; both terminals are electrically symmetric.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Transient current path (bidirectional) | Conducts surge current equally in either direction; connects across protected line and ground or between differential lines |
| Cathode/Anode (symmetrical) | Transient current return path | Completes low-inductance clamping loop; requires short PCB traces to minimize VL = L·di/dt overshoot |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating automotive signals (e.g., LIN, CAN stubs, sensor bridges) without polarity concerns |
| Low dynamic resistance (11.5 mΩ) | Reduces clamping voltage rise under fast-rising transients (e.g., ISO 7637-2 Pulse 3b), preserving safe operating area for downstream FETs |
| AEC-Q101 qualification | Confirms reliability for 15-year automotive service life under thermal cycling, humidity, and mechanical vibration stress |
| JEDEC SMC package | Ensures compatibility with standard SMT assembly processes and thermal management practices used in Tier-1 ECU manufacturing |
| UL94 V0 flammability rating | Meets automotive interior material safety requirements for under-dash and cabin-mounted electronics |
Applications
| Engine Control Unit (ECU) Power Input | LIN Bus Transceiver Protection |
|---|---|
|
Use Scenario: Protects 12 V supply rail of gasoline/diesel engine ECUs against load dump (ISO 7637-2 Pulse 5b) and alternator switching transients. IC Role / Device Role / Timing Role: Bidirectional TVS placed between battery input and DC-DC converter input, clamping surges within 1 ns response time. Use Value: Maintains VIN ≤ 21.5 V during 140 A transients, preventing latch-up or burnout of upstream PMICs rated for 28 V absolute max. |
Use Scenario: Shields LIN physical layer transceivers from ESD and coupled noise on shared vehicle harnesses. IC Role / Device Role / Timing Role: Placed across LIN bus (LIN-H/L) and chassis ground, absorbing ±30 kV contact discharge per ISO 10605. Use Value: Limits bus voltage excursion to ≤21.5 V during ESD event, ensuring transceiver remains functional without reset or data corruption. |
| Body Control Module (BCM) Sensor Interface | Electric Power Steering (EPS) Motor Driver |
|
Use Scenario: Guards analog inputs (e.g., ambient temperature, rain sensor) in BCMs exposed to harness-level transients. IC Role / Device Role / Timing Role: Connected between sensor signal line and ground, with low 0.2 µA leakage preserving ADC accuracy. Use Value: Prevents false triggers or offset drift in precision sensor circuits while surviving repeated ISO 7637-2 Pulse 3a (−220 V) events. |
Use Scenario: Protects gate drivers and current sense amplifiers in EPS motor control boards from inductive kickback and battery reversal. IC Role / Device Role / Timing Role: Mounted across H-bridge high-side driver supply and ground, rated for 175 °C junction operation near MOSFETs. Use Value: Withstands continuous 150 °C board temperatures and clamps 112 V Pulse 2a spikes without parameter shift or failure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ15CA (Bourns) | Same VBR range (14.3–15.8 V) but lower PPP = 400 W; higher VCL = 24.4 V at 16.3 A | Rated only for non-automotive industrial use; lacks AEC-Q101, ISO 7637-2, and 175 °C Tj validation | Select when cost sensitivity outweighs automotive qualification and surge robustness requirements |
| TPSMB15CA (Texas Instruments) | VBR = 14.3–15.8 V, VCL = 24.4 V at 16.3 A, PPP = 600 W; AEC-Q101 qualified but not ISO 7637-2 tested | Validated for automotive ambient but not certified for Pulse 1/2a/3a/3b; limited to lower-energy ESD-only scenarios | Choose for infotainment or ADAS camera modules where ESD dominates and load dump risk is mitigated elsewhere |
Compared with SMAJ15CA and TPSMB15CA, SM30T15CAY delivers 5× higher peak pulse power (3000 W vs. ≤600 W), 3.3× lower clamping voltage at rated current (21.5 V vs. ≥24.4 V), and full ISO 7637-2 certification - making it the only option qualified for direct battery rail protection in powertrain and chassis systems.
Availability
SM30T15CAY is available at Aetrix Electronics and suitable for engine control units, body control modules, electric power steering systems, and LIN bus networks requiring stable component supply across extended automotive production lifecycles.
Supply support for SM30T15CAY 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 management solutions with vertical manufacturing and application-specific design expertise.
The SM30Txx series belongs to ST's automotive-grade TVS portfolio, engineered specifically for ISO 7637-2 and ISO 10605 compliance in harsh-temperature vehicle environments - targeting powertrain, chassis, and body electronics where reliability under electrical stress is non-negotiable.
FAQ
What is the difference between SM30T15AY and SM30T15CAY?
SM30T15AY is unidirectional (anode-to-cathode conduction only), suited for DC power rail protection where polarity is fixed. SM30T15CAY is bidirectional, with symmetrical clamping in both directions - required for AC-coupled buses like LIN or differential sensor interfaces where voltage polarity reverses. Their VBR, VCL, and surge ratings are identical, but pin assignment and application context differ fundamentally.
Does SM30T15CAY require a heatsink for 3000 W surge handling?
No external heatsink is needed for single-event surge handling. The 3000 W rating applies to a single 10/1000 µs pulse with Tj initial = 25 °C. Thermal impedance (Zth(j-a)) is 100 °C/W on standard FR4 with 1 cm² copper per lead, allowing safe junction temperature rise to ≤175 °C during transient. Continuous power dissipation remains negligible due to sub-µA leakage.
Can SM30T15CAY be used in 24 V commercial vehicle systems?
No - SM30T15CAY is specified for 12 V nominal systems. Its 15 V VBR and 21.5 V VCL provide insufficient margin above 24 V system peaks (up to 28 V). For 24 V applications, ST recommends SM30T28CAY (VBR = 26.7–29.5 V, VCL = 38.9 V) or SM30T33CAY (VBR = 31.1–34.3 V, VCL = 45.4 V), both validated for ISO 7637-2 in 24 V architectures.
How does the 10 × 10−4/°C temperature coefficient affect clamping performance?
The αT = 10 × 10−4/°C means VBR increases by 0.1% per °C rise above 25 °C. At 150 °C, VBR rises ~12.5%, to ~16.9 V - still well below VCL of 21.5 V. This positive TC ensures clamping remains effective at high ambient temperatures, unlike negative-TC Zener-based TVS that degrade with heating.
SM30T15CAY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- SM30TY, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 13V
- Voltage - Breakdown (Min):
- 14.3V
- Voltage - Clamping (Max) @ Ipp:
- 21.5V
- Current - Peak Pulse (10/1000µs):
- 140A
- Power - Peak Pulse:
- 3000W (3kW)
- 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
SM30T15CAY FAQ
1.How can I place an order for SM30T15CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM30T15CAY 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 SM30T15CAY reliable?
The price and inventory of SM30T15CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM30T15CAY is usually 5 days.
3.What payment methods are accepted for SM30T15CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM30T15CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM30T15CAY?
SM30T15CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM30T15CAY 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 SM30T15CAY?
For technical support, including SM30T15CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM30T15CAY requirements.
6.How does Aetrix verify that SM30T15CAY is sourced from the original manufacturer or authorized distributors?
All SM30T15CAY 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 SM30T15CAY meets industry standards.
7.What is the process for return or replacement of SM30T15CAY?
All SM30T15CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM30T15CAY, 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 SM30T15CAY part is unused and in its original packaging.
Return procedure for SM30T15CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM30T15CAY Tags
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