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STMicroelectronics SM15T39CAY
- Part No.:
- SM15T39CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM15T39CAY.pdf
- Description:
- TVS DIODE 33.3VWM 69.7VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:10,216
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Product details
Overview
SM15T39CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppression diode in SMC package, designed for ISO 7637-2 pulse protection (Pulse 1: −150 V; Pulse 2a: +112 V; Pulse 3a: −220 V; Pulse 3b: +150 V) and ESD immunity per ISO 10605 (±30 kV air/contact). It delivers 1500 W peak pulse power (10/1000 µs), clamps at 53.9 V (max) under 28 A surge, and operates up to 150 °C junction temperature.
For engineers reviewing the SM15T39CAY datasheet, SM15T39CAY pinout, SM15T39CAY application, or SM15T39CAY equivalent, this device is selected for high-reliability 12 V/24 V automotive power line protection where low leakage (0.2 µA @ 25 °C), tight VBR tolerance (33.3–41.0 V), and AEC-Q101 qualification are mandatory.
Technical Context
This bidirectional TVS uses planar silicon technology to achieve stable breakdown voltage (VBR = 33.3–41.0 V at IBR = 1 mA), low dynamic resistance (RD = 0.461 Ω), and minimal capacitance (<1000 pF at 1 MHz). Its thermal design supports continuous operation at Tj = 150 °C with derated power up to 1250 W.
The device meets IEC 61000-4-4 Level 4 (±4 kV), exceeds ISO 10605 Level 4 (±30 kV), and complies with UL94 V0, J-STD-020 MSL Level 1, and JEDEC registered SMC outline - enabling robust placement on FR4 PCBs with 70 µm copper.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power (10/1000 µs) | 1500 W - sustains automotive load dump surges without failure |
| Clamping Voltage (VCL) | 53.9 V max at 28 A - limits downstream IC voltage stress during ISO 7637-2 Pulse 1/2a/3a/3b events |
| Breakdown Voltage (VBR) | 33.3–41.0 V at 1 mA - ensures reliable triggering before protected circuit damage |
| Leakage Current (IR) | 0.2 µA @ 25 °C, 1 µA @ 85 °C - prevents battery drain in always-on automotive modules |
| Junction Temperature Range | −55 to +150 °C - supports under-hood deployment in engine control units and body controllers |
| ESD Withstand (ISO 10605) | ±30 kV air/contact (C = 330 pF/R = 330 Ω) - exceeds automotive ESD immunity requirements |
| Package | SMC (DO-214AB) - industry-standard surface-mount footprint with IPC7531-compliant land pattern |
Pinout & Package
SM15T39CAY is housed in an SMC (DO-214AB) plastic package with two terminals: Cathode and Anode. The bidirectional configuration means both terminals function symmetrically as surge current paths - no polarity-sensitive mounting required.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Surge current entry (negative transients) | Accepts reverse-polarity surges (e.g., ISO 7637-2 Pulse 1: −150 V) and routes energy to cathode via internal PN junction |
| Cathode | Surge current entry (positive transients) | Accepts positive transients (e.g., ISO 7637-2 Pulse 2a: +112 V) and routes energy to anode via internal PN junction |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive use across temperature, humidity, and mechanical shock stress profiles |
| Low dynamic resistance (RD) | 0.461 Ω - minimizes clamping voltage rise under high-current transients |
| Matte tin lead finish | Complies with JESD 22-B102 E3 and MIL-STD-750 Method 2026 - ensures solderability and whisker resistance |
| High-temperature reliability | Rated for 150 °C Tj with 1250 W pulse capability - enables compact placement near heat sources |
Applications
| Engine Control Unit (ECU) Power Input | Body Control Module (BCM) LIN Bus Line |
|---|---|
Use Scenario: Protects 12 V supply rail of gasoline/diesel ECUs against load dump, jump-start, and alternator ripple. IC Role / Device Role / Timing Role: Bidirectional clamping device placed between battery input and DC-DC converter input stage. Use Value: Limits transient voltage to ≤53.9 V during ISO 7637-2 Pulse 1 (−150 V), preventing MOSFET gate oxide rupture and regulator latch-up. | Use Scenario: Shields LIN transceiver PHY layer from ESD events and coupled noise on vehicle body wiring harnesses. IC Role / Device Role / Timing Role: Low-capacitance bidirectional TVS mounted directly at LIN connector interface. Use Value: Maintains signal integrity with <1000 pF capacitance while surviving ±30 kV contact discharge per ISO 10605. |
| Advanced Driver Assistance System (ADAS) Camera Power | Electric Power Steering (EPS) Motor Driver Supply |
Use Scenario: Safeguards 12 V input of rear-view/front-facing cameras exposed to long cable runs and chassis coupling. IC Role / Device Role / Timing Role: Primary overvoltage clamp on camera module power entry point, upstream of LDOs and image sensors. Use Value: Enables uninterrupted operation during ISO 7637-2 Pulse 3b (+150 V) by clamping within 1 ns and dissipating 1500 W peak power. | Use Scenario: Protects H-bridge driver ICs and gate drivers from inductive kickback during EPS motor commutation. IC Role / Device Role / Timing Role: Bidirectional TVS placed across motor supply rails (VBAT–GND) to absorb flyback energy. Use Value: Survives repeated 8/20 µs surges up to 69.7 A (per IEC 61000-4-5) without parameter shift or degradation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional automotive TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ39CA | Lower peak power (400 W), higher VCL (67.0 V at 6.0 A), SMA package | Not AEC-Q101 qualified; unsuitable for under-hood or safety-critical systems | Select only for non-automotive, low-energy board-level ESD protection |
| 1.5KE39CA | Higher VCL (63.0 V at 23.7 A), axial DO-201 package, no AEC-Q101 rating | Lacks SMC surface-mount compatibility and automotive thermal cycling validation | Use only in legacy through-hole designs with manual assembly and no automotive qualification requirement |
Compared with SMAJ39CA and 1.5KE39CA, SM15T39CAY provides 3.75× higher surge power handling, 10.1 V lower clamping at rated current, and full AEC-Q101 compliance - making it the sole choice for modern automotive power rail protection where space, reliability, and regulatory alignment are critical.
Availability
SM15T39CAY is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS camera systems, and electric power steering systems requiring stable component supply across extended temperature ranges and automotive lifecycle demands.
Supply support for SM15T39CAY 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 belongs to ST's automotive-qualified TVS portfolio, engineered specifically for ISO 7637-2 and ISO 10605 compliance in 12 V/24 V vehicle electrical architectures.
FAQ
Is SM15T39CAY unidirectional or bidirectional?
SM15T39CAY is a bidirectional TVS diode, indicated by the "CA" suffix in its order code. It protects against both positive and negative transients symmetrically, with identical VBR (33.3–41.0 V) and VCL (53.9 V) specifications for either polarity - essential for AC-coupled lines or floating power domains in automotive networks.
What is the maximum clamping voltage at 28 A surge current?
The maximum clamping voltage (VCL) for SM15T39CAY at 28 A (10/1000 µs waveform) is 53.9 V, measured at Tamb = 25 °C. This value increases with junction temperature at a coefficient of 10 × 10−4/°C, reaching ~56.7 V at Tj = 125 °C per the αT coefficient in Table 2.
Does SM15T39CAY meet AEC-Q101 requirements?
Yes, SM15T39CAY is explicitly AEC-Q101 qualified per the manufacturer's datasheet DS6928 Rev 6. It has passed stress tests including temperature cycling, high-temperature operating life, and unbiased highly accelerated stress testing - confirming suitability for automotive under-hood and chassis-mounted applications.
What is the recommended PCB footprint for SM15T39CAY?
The recommended footprint follows IPC7531 and matches the JEDEC DO-214AB (SMC) outline: pad length 5.11 mm, pad width 3.14 mm, center-to-center spacing 8.19 mm, with 1.54 mm solder mask clearance. Thermal performance improves with ≥2 cm² copper area per lead, reducing Rth(j-a) to ≤60 °C/W per Figure 12.
SM15T39CAY 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):
- 33.3V
- Voltage - Breakdown (Min):
- 37.1V
- Voltage - Clamping (Max) @ Ipp:
- 69.7V
- Current - Peak Pulse (10/1000µs):
- 143A (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
SM15T39CAY FAQ
1.How can I place an order for SM15T39CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM15T39CAY 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 SM15T39CAY reliable?
The price and inventory of SM15T39CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM15T39CAY is usually 5 days.
3.What payment methods are accepted for SM15T39CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM15T39CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM15T39CAY?
SM15T39CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM15T39CAY 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 SM15T39CAY?
For technical support, including SM15T39CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM15T39CAY requirements.
6.How does Aetrix verify that SM15T39CAY is sourced from the original manufacturer or authorized distributors?
All SM15T39CAY 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 SM15T39CAY meets industry standards.
7.What is the process for return or replacement of SM15T39CAY?
All SM15T39CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM15T39CAY, 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 SM15T39CAY part is unused and in its original packaging.
Return procedure for SM15T39CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM15T39CAY Tags
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