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STMicroelectronics SMA6T39AY
- Part No.:
- SMA6T39AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMA6T39AY.pdf
- Description:
- TVS DIODE 33.3VWM 69.7VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:2,831
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Product details
Overview
SMA6T39AY from STMicroelectronics is a unidirectional 600 W automotive-grade transient voltage suppression (TVS) diode in SMA package, designed for ISO 7637-2 pulse protection and ISO 10605 ESD immunity. It features 39 V breakdown voltage (VBR = 39.0 V), 53.9 V clamping voltage at 11.1 A (10/1000 µs), and ≤0.2 µA leakage at 25 °C - deployed in power line surge protection for engine control units and body electronics.
For engineers reviewing the SMA6T39AY datasheet, SMA6T39AY pinout, SMA6T39AY application, or SMA6T39AY equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1 (−150 V), junction temperature derating to +150 °C, unidirectional polarity for DC rail protection, and JEDEC DO-214AC-compliant SMA footprint compatibility with automotive PCB layouts.
Technical Context
This TVS diode uses planar silicon technology to achieve low leakage and high thermal stability, enabling reliable operation up to Tj = +150 °C in under-hood environments. Its dynamic resistance (RD = 0.504 Ω) and voltage-temperature coefficient (αT = 100 ppm/°C) are specified to support accurate clamping prediction across automotive temperature ranges.
The device meets AEC-Q101 qualification and exceeds IEC 61000-4-2 Level 4 (±30 kV air/contact discharge) and ISO 10605 (C = 330 pF, R = 330 Ω). It is rated for 4 kW peak pulse power under 8/20 µs waveform, with defined response to ISO 7637-2 transients including Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Breakdown Voltage (VBR) | 39.0 V min at IBR = 1 mA - ensures stable triggering above nominal 36 V battery systems |
| Clamping Voltage (VCL) | 53.9 V max at IPP = 11.1 A (10/1000 µs) - limits downstream IC stress during load dump |
| Peak Pulse Power | 600 W (10/1000 µs), 4 kW (8/20 µs) - supports both slow and fast surge events per ISO standards |
| Leakage Current (IR) | ≤0.2 µA at VRM = 33.3 V, 25 °C - minimizes standby power loss in always-on circuits |
| Junction Temperature Range | −55 °C to +150 °C - validated for under-hood placement near engines and power modules |
| ESD Withstand | ±30 kV (air & contact, ISO 10605, C = 150/330 pF) - exceeds automotive ESD immunity requirements |
| Package | SMA (DO-214AC) - JEDEC-registered surface-mount outline with 5.43 mm × 2.63 mm footprint |
Pinout & Package
SMA6T39AY is housed in a two-terminal SMA (DO-214AC) package with cathode-banded marking. The device has no internal circuitry beyond the PN junction; terminals are anode and cathode, with cathode identified by the band on the body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Ground reference terminal | Connected to system ground or chassis return path; defines current flow direction during surge |
| Cathode | Protected line terminal | Connected to protected supply rail (e.g., 12 V/24 V/36 V); clamps positive transients to ground |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive use with temperature cycling, humidity, and mechanical shock testing per AEC standard |
| Low dynamic resistance | RD = 0.504 Ω enables tighter clamping and lower let-through energy during fast surges |
| High-temperature stability | Specified performance maintained up to Tj = +150 °C - critical for proximity to power converters and ECUs |
| JEDEC DO-214AC compliance | Ensures consistent solder reflow behavior and mechanical reliability in automated SMT assembly |
| Matte tin lead finish | RoHS-compliant plating with J-STD-002 solderability and JESD 22-B102 E3 whisker resistance |
Applications
| Engine Control Unit (ECU) Power Input | Body Control Module (BCM) CAN Bus Protection |
|---|---|
Use Scenario: Protects 12 V/24 V input rails of engine control units against load dump and alternator transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and DC-DC input, clamping pulses within 1 ns response time. Use Value: Limits peak voltage to ≤53.9 V during ISO 7637-2 Pulse 1 (−150 V), preventing damage to LDOs and microcontrollers. | Use Scenario: Shields CAN transceiver power pins from coupled surges induced on adjacent harnesses. IC Role / Device Role / Timing Role: Secondary protection stage after common-mode choke, absorbing differential-mode energy on VCC line. Use Value: Maintains <0.2 µA leakage at 33.3 V reverse bias, avoiding false wake-up or quiescent current violations in sleep mode. |
| Advanced Driver Assistance Systems (ADAS) Camera Power | Electric Power Steering (EPS) Motor Driver Supply |
Use Scenario: Safeguards 5 V or 3.3 V camera module supplies against ESD and board-level coupling during vehicle assembly. IC Role / Device Role / Timing Role: Final-stage TVS on regulated output, triggered only during >30 kV ESD events per ISO 10605. Use Value: Clamps ±30 kV discharges to <53.9 V with sub-1 ns response, preserving image sensor and serializer IC integrity. | Use Scenario: Protects high-current motor driver ICs from inductive kickback and battery reversal transients. IC Role / Device Role / Timing Role: Primary surge suppressor on 12 V/24 V gate driver supply, rated for 4 kW (8/20 µs) pulse handling. Use Value: Withstands ISO 7637-2 Pulse 3b (+150 V) without degradation, ensuring continuous torque control during fault conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMA6T39A | Same electrical specs but non-automotive grade (no AEC-Q101 qualification) | Not suitable for production automotive systems requiring qualification evidence | Select SMA6T39AY when AEC-Q101 documentation and traceable lot data are mandatory |
| SMCJ39A | Higher 1500 W rating (10/1000 µs), larger SMC (DO-214AB) package, same VBR/VCL | Used where higher surge margin is needed and board space allows larger footprint | Choose SMA6T39AY for space-constrained automotive modules needing AEC-Q101 and SMA fit |
Compared with SMA6T39A and SMCJ39A, SMA6T39AY uniquely combines AEC-Q101 validation, SMA package size, and precise 39 V breakdown - making it optimal for compact, production-grade automotive power rail protection where qualification, footprint, and clamping accuracy are jointly critical.
Availability
SMA6T39AY is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS camera systems, and electric power steering designs requiring stable component supply across automotive production lifecycles.
Supply support for SMA6T39AY 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.
SMA6T39AY belongs to the SMA6TY Transil series - engineered specifically for robust, high-reliability transient suppression in automotive electronics subject to ISO 7637-2 and ISO 10605 stress conditions.
FAQ
What is the maximum clamping voltage of SMA6T39AY under a 10/1000 µs surge?
The maximum clamping voltage is 53.9 V at 11.1 A peak pulse current (10/1000 µs), measured at Tamb = 25 °C. This value increases with junction temperature using αT = 100 ppm/°C, reaching ~56.2 V at Tj = 125 °C per datasheet formula VCL(Tj) = VCL(25 °C) × [1 + αT × (Tj − 25)].
Is SMA6T39AY bidirectional or unidirectional?
SMA6T39AY is unidirectional, indicated by the "A" suffix in its order code (vs. "CAY" for bidirectional). It conducts only during positive transients on the cathode side and blocks reverse voltage up to 33.3 V (VRM), making it suitable for DC power rail protection with defined polarity.
Does SMA6T39AY meet AEC-Q101 requirements?
Yes - SMA6T39AY is explicitly AEC-Q101 qualified, with test reports covering temperature cycling, high-temperature operating life, unbiased highly accelerated stress test, and mechanical shock. This qualification is documented in ST's official DS6931 datasheet Rev 9 and supported by ST's automotive product status portal.
What is the recommended PCB footprint for SMA6T39AY?
The recommended footprint matches JEDEC DO-214AC: 5.43 mm × 2.63 mm pad length/width, with 1.40 mm pad spacing and 1.64 mm pad width per side. ST specifies copper area ≥1 cm² per lead for optimal thermal dissipation, and the device must be placed outside keep-out zones for reflow profile compliance per J-STD-020 MSL level 1.
SMA6T39AY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AC, SMA
- Series:
- SMA6TY, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 33.3V
- Voltage - Breakdown (Min):
- 37.1V
- Voltage - Clamping (Max) @ Ipp:
- 69.7V
- Current - Peak Pulse (10/1000µs):
- 57A (8/20µs)
- Power - Peak Pulse:
- 600W
- 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:
- DO-214AC (SMA)
SMA6T39AY FAQ
1.How can I place an order for SMA6T39AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA6T39AY 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 SMA6T39AY reliable?
The price and inventory of SMA6T39AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA6T39AY is usually 5 days.
3.What payment methods are accepted for SMA6T39AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA6T39AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA6T39AY?
SMA6T39AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA6T39AY 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 SMA6T39AY?
For technical support, including SMA6T39AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA6T39AY requirements.
6.How does Aetrix verify that SMA6T39AY is sourced from the original manufacturer or authorized distributors?
All SMA6T39AY 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 SMA6T39AY meets industry standards.
7.What is the process for return or replacement of SMA6T39AY?
All SMA6T39AY units undergo pre-shipment inspection (PSI). If there is an issue with SMA6T39AY, 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 SMA6T39AY part is unused and in its original packaging.
Return procedure for SMA6T39AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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