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STMicroelectronics SMA6T12AY
- Part No.:
- SMA6T12AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMA6T12AY.pdf
- Description:
- TVS DIODE 10.2VWM 21.7VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:9,371
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Product details
Overview
SMA6T12AY from STMicroelectronics is a unidirectional 600 W automotive-grade transient voltage suppressor (TVS) diode designed for ISO 7637-2 pulse protection in 12 V battery systems. It features a 12.0 V nominal breakdown voltage (VBR), 16.7 V maximum clamping voltage (VCL) at 36 A (10/1000 µs), and 0.2 µA leakage current at 25 °C - optimized for engine control units, body control modules, and LIN/CAN node protection.
For engineers reviewing the SMA6T12AY datasheet, SMA6T12AY pinout, SMA6T12AY application, or SMA6T12AY equivalent, this device delivers verified surge immunity per ISO 10605 (±30 kV ESD), ISO 7637-2 Pulse 1/2a/3a/3b, and IEC 61000-4-4 Level 4 - with validated thermal stability up to Tj = 150 °C and JEDEC DO-214AC (SMA) package compatibility.
Technical Context
This TVS operates as a clamping-type overvoltage protector using planar silicon junction technology. Its unidirectional configuration enables forward-biased operation during negative transients (e.g., ISO 7637-2 Pulse 1: −150 V) while blocking reverse leakage below 12.6 V. The low dynamic resistance (RD = 0.114 Ω) ensures minimal voltage overshoot under high-current surges.
It meets AEC-Q101 stress requirements across temperature cycling, humidity bias, and mechanical shock. Junction capacitance remains below 1000 pF at 0 V (f = 1 MHz), supporting signal integrity in LIN bus and sensor interface lines without compromising EMI filtering performance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 10.2 / 11.4 / 12.6 V - defines precise turn-on threshold for reliable clamping onset in 12 V automotive systems |
| VCL @ 36 A (10/1000 µs) | 16.7 V - limits downstream IC voltage stress during load dump or alternator surge events |
| IPP (10/1000 µs) | 36.0 A - supports 600 W peak power dissipation without thermal runaway at Tj ≤ 150 °C |
| IR @ VRM = 10 V | 0.2 µA at 25 °C - ensures negligible standby current draw in always-on vehicle modules |
| Tj max | +150 °C - enables placement near heat sources (e.g., powertrain ECUs) without derating |
| Package | DO-214AC (SMA) - JEDEC-registered surface-mount outline with IPC-7531-compliant footprint |
| ESD Rating | ±30 kV contact/air (ISO 10605, C = 150/330 pF) - exceeds automotive OEM requirements for assembly-line ESD robustness |
Pinout & Package
The SMA6T12AY uses a 2-terminal DO-214AC (SMA) package with cathode band marking. Terminals are non-polarized for PCB layout flexibility but functionally asymmetric: anode connects to protected line, cathode to ground reference.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Protected circuit input | Connected to sensitive node (e.g., LIN bus line); conducts surge current toward ground when VAK > VBR |
| Cathode (banded end) | Ground reference path | Low-inductance connection to chassis or power ground plane; carries full surge current during clamping |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood deployment including temperature cycling, humidity bias, and mechanical shock testing |
| Low leakage current | 0.2 µA at 25 °C and 1 µA at 85 °C - prevents battery drain in always-on vehicle subsystems |
| High surge capability | 600 W (10/1000 µs) and 4 kW (8/20 µs) - handles both slow-load-dump and fast-switching transients |
| Thermal stability | Rated for continuous operation up to Tj = 150 °C - eliminates need for thermal derating in compact ECUs |
| ESD robustness | Exceeds ISO 10605 Level 4 (±30 kV) - protects against human-body-model and machine-model ESD events |
Applications
| Engine Control Unit (ECU) | Body Control Module (BCM) |
|---|---|
Use Scenario: Protection of 12 V supply rail against load dump pulses (ISO 7637-2 Pulse 5a) and alternator switching transients. IC Role / Device Role / Timing Role: Clamping TVS placed between battery feed and DC-DC converter input stage. Use Value: Limits voltage excursion to ≤16.7 V during 36 A surge, preventing overvoltage shutdown of buck controller ICs. |
Use Scenario: Shielding LIN bus transceivers from ESD events during service port connection/disconnection. IC Role / Device Role / Timing Role: Low-capacitance unidirectional clamp on LIN data line referenced to local ground. Use Value: Maintains signal integrity with <1000 pF capacitance while suppressing ±30 kV air discharge without latch-up. |
| Advanced Driver Assistance System (ADAS) Camera Module | Electric Power Steering (EPS) Motor Driver |
Use Scenario: Guarding image sensor power supply against ignition-induced transients in front-end camera assemblies. IC Role / Device Role / Timing Role: Primary overvoltage clamp on 5 V/3.3 V LDO input rail upstream of CMOS image sensor. Use Value: Prevents pixel corruption or reset events by clamping sub-20 V spikes within 1 ns response time. |
Use Scenario: Safeguarding H-bridge gate drivers from inductive kickback during motor phase commutation. IC Role / Device Role / Timing Role: Bidirectional suppression (using SMA6T12CAY variant) across motor phase outputs. Use Value: Absorbs 4 kW (8/20 µs) energy from flyback currents, eliminating need for external snubbers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMA6T12CAY | Bidirectional version with symmetric ±12 V breakdown; higher leakage (1 µA at 85 °C) | Required for AC-coupled lines (e.g., CAN differential pairs) where polarity reversal occurs | Select when protecting bidirectional data buses; avoid for DC power rails due to doubled leakage path |
| SMAJ12A | Same DO-214AC package but lower 400 W rating (10/1000 µs); VCL = 19.9 V at 20 A | Limited to non-critical 12 V accessories (e.g., infotainment USB ports) lacking ISO 7637-2 compliance | Use only where cost sensitivity outweighs automotive surge margin; not qualified to AEC-Q101 |
Compared with SMA6T12CAY and SMAJ12A, the SMA6T12AY provides superior clamping precision (16.7 V vs. ≥19.9 V), AEC-Q101 validation, and lower leakage - making it the preferred choice for safety-critical 12 V power domains requiring guaranteed ISO 7637-2 Pulse 1/2a/3a/3b immunity.
Availability
SMA6T12AY is available at Aetrix Electronics and suitable for engine control units, body control modules, and ADAS camera modules requiring stable component supply across automotive production lifecycles.
Supply support for SMA6T12AY 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 capabilities.
The SMA6TY series belongs to ST's Transil™ TVS portfolio, engineered specifically for automotive-grade transient suppression in 12 V and 24 V battery systems - emphasizing AEC-Q101 reliability, low leakage, and ISO-compliant surge handling.
FAQ
What is the maximum clamping voltage of SMA6T12AY under a 36 A surge?
The SMA6T12AY exhibits a maximum clamping voltage (VCL) of 16.7 V when subjected to a 36 A peak pulse current with a 10/1000 µs waveform at Tj = 25 °C. This value is measured per IEC 61000-4-5 and confirmed in Table 2 of DS6931 Rev 9. At elevated junction temperatures, VCL increases linearly per the αT coefficient (7.8 × 10−4/°C).
Can SMA6T12AY be used in 24 V automotive systems?
No - SMA6T12AY is rated for 12 V nominal systems. Its 12.0 V breakdown voltage and 16.7 V clamping level are optimized for 12 V battery architectures. For 24 V systems, ST recommends SMA6T24AY (VBR = 24.0 V, VCL = 33.2 V) or SMA6T28AY (VBR = 28.1 V), both sharing identical AEC-Q101 qualification and DO-214AC packaging.
Does SMA6T12AY require a heatsink for 600 W surge handling?
No external heatsink is required. The device achieves 600 W (10/1000 µs) peak power dissipation through its planar junction design and thermal coupling to the PCB copper area. Figure 12 in DS6931 shows Rth(j-a) drops to ~3.5 °C/W with 1 cm² copper per lead on FR4 - sufficient for single-pulse automotive transients without sustained thermal accumulation.
How does SMA6T12AY differ from SMAJ12A in layout compatibility?
Both share identical DO-214AC (SMA) mechanical dimensions and IPC-7531 footprint, enabling direct PCB replacement. However, SMA6T12AY requires stricter solder profile adherence due to its matte tin plating and MSL Level 1 rating, whereas SMAJ12A permits longer reflow exposure. Layout reuse is electrically valid but demands updated process validation for automotive production.
SMA6T12AY 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):
- 10.2V
- Voltage - Breakdown (Min):
- 11.4V
- Voltage - Clamping (Max) @ Ipp:
- 21.7V
- Current - Peak Pulse (10/1000µs):
- 184A (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)
SMA6T12AY FAQ
1.How can I place an order for SMA6T12AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA6T12AY 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 SMA6T12AY reliable?
The price and inventory of SMA6T12AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA6T12AY is usually 5 days.
3.What payment methods are accepted for SMA6T12AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA6T12AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA6T12AY?
SMA6T12AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA6T12AY 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 SMA6T12AY?
For technical support, including SMA6T12AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA6T12AY requirements.
6.How does Aetrix verify that SMA6T12AY is sourced from the original manufacturer or authorized distributors?
All SMA6T12AY 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 SMA6T12AY meets industry standards.
7.What is the process for return or replacement of SMA6T12AY?
All SMA6T12AY units undergo pre-shipment inspection (PSI). If there is an issue with SMA6T12AY, 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 SMA6T12AY part is unused and in its original packaging.
Return procedure for SMA6T12AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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