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STMicroelectronics SMA6T28CAY
- Part No.:
- SMA6T28CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMA6T28CAY.pdf
- Description:
- TVS DIODE 24VWM 44.3VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:4,977
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Product details
Overview
SMA6T28CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppression (TVS) diode in SMA (DO-214AC) package, designed to protect 24 V automotive electronics against ISO 7637-2 pulses (Pulse 1: −150 V; Pulse 2a: +112 V; Pulse 3a: −220 V; Pulse 3b: +150 V) and ESD per ISO 10605 (±30 kV air/contact). It delivers 600 W peak pulse power (10/1000 µs), clamps at 37.8 V (max) under 16 A surge, and operates up to 150 °C junction temperature.
For engineers reviewing the SMA6T28CAY datasheet, SMA6T28CAY pinout, SMA6T28CAY application, or SMA6T28CAY equivalent, key selection criteria include bidirectional clamping capability, low leakage (0.2 µA @ 25 °C), AEC-Q101 qualification, ISO 7637-2 compliance for 24 V systems, and thermal stability across −55 °C to +150 °C operating range.
Technical Context
This TVS diode uses planar silicon technology to achieve low dynamic resistance (0.516 Ω at 10/1000 µs), high junction temperature tolerance (Tj max = 150 °C), and stable clamping performance over temperature. Its bidirectional configuration enables symmetrical protection of differential or floating signal lines without polarity constraints.
It meets stringent automotive immunity standards: IEC 61000-4-4 Level 4 (4 kV), ISO 10605 (±30 kV with both 150 pF/330 Ω and 330 pF/330 Ω models), and ISO 7637-2 Pulse 1–3b waveforms - critical for CAN, LIN, sensor interfaces, and body control modules in 24 V commercial vehicle systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power (10/1000 µs) | 600 W - sustains 16 A surge current at 37.8 V clamping without failure |
| Clamping Voltage (IPP = 16 A, 10/1000 µs) | 37.8 V max - limits downstream IC voltage stress during ISO 7637-2 Pulse 1/3a transients |
| Breakdown Voltage (VBR) | 26.7–29.5 V @ IBR = 1 mA - ensures reliable turn-on before system overvoltage damage |
| Leakage Current (IR) | 0.2 µA @ 25 °C, 1 µA @ 85 °C - minimizes standby power loss in always-on automotive circuits |
| Operating Junction Temp. | −55 °C to +150 °C - supports under-hood placement near engines or powertrain ECUs |
| ESD Withstand (ISO 10605) | ±30 kV air & contact discharge - exceeds automotive ESD immunity requirements for exposed connectors |
| Package | SMA (DO-214AC) - JEDEC-registered surface-mount outline compatible with standard FR4 PCB footprints |
Pinout & Package
SMA6T28CAY is housed in a two-terminal SMA (DO-214AC) package with cathode band marking. The device has no polarity-sensitive pins - both terminals are electrically symmetric due to its bidirectional construction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Transient current path | Both terminals conduct equally during positive or negative surges - enables placement across any two points requiring bidirectional clamping |
| Cathode band (marking) | Orientation indicator | Visible band identifies terminal 1 per DO-214AC standard; irrelevant for function but required for automated assembly alignment |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive use including temperature cycling, humidity bias, and mechanical shock per JESD22 standards |
| Low dynamic resistance (RD) | 0.516 Ω - reduces clamping voltage overshoot during fast 8/20 µs surges (e.g., ISO 7637-2 Pulse 3b) |
| Junction capacitance | <100 pF @ 0 V (typ.) - preserves signal integrity on high-speed lines like CAN FD or LIN bus |
| Thermal robustness | Rth(j-a) = ~40 °C/W on 1 cm² copper - enables reliable operation without heatsinking in space-constrained modules |
| Lead finish | Matte tin plating - ensures solderability compatibility with lead-free reflow profiles (MSL Level 1, J-STD-020) |
Applications
| Automotive CAN Bus Protection | 24 V Sensor Interface Protection |
|---|---|
Use Scenario: Protecting CAN_H/CAN_L lines in commercial vehicle telematics modules exposed to load dump and ESD events. IC Role / Device Role / Timing Role: Bidirectional voltage clamp placed across differential pair to limit transient excursions below transceiver absolute maximum ratings. Use Value: Prevents CAN transceiver latch-up or permanent damage during ISO 7637-2 Pulse 2a (+112 V) and ISO 10605 ±30 kV discharges. |
Use Scenario: Safeguarding analog outputs of pressure/temperature sensors in engine control units subject to battery reversal and inductive switching noise. IC Role / Device Role / Timing Role: Low-leakage TVS shunting surge energy away from precision ADC inputs and op-amp front-ends. Use Value: Maintains sensor accuracy by limiting clamping voltage to 37.8 V while contributing only 0.2 µA leakage at 25 °C. |
| Body Control Module (BCM) Power Input | ADAS Camera Power Line Protection |
Use Scenario: Input-stage protection for BCMs powered from 24 V battery rail, where load dump and jump-start transients occur. IC Role / Device Role / Timing Role: Primary clamping device placed upstream of DC-DC converters to absorb ISO 7637-2 Pulse 1 (−150 V) and Pulse 3a (−220 V). Use Value: Enables single-device protection with 600 W rating - eliminates need for series resistors or additional TVS stages in compact designs. |
Use Scenario: Protecting 12 V/24 V power input of surround-view camera modules mounted externally on trucks or buses. IC Role / Device Role / Timing Role: Robust front-end clamp handling repeated ESD events and long-duration transients during vehicle wash or maintenance. Use Value: Sustains 150 °C junction temperature and passes ISO 10605 ±30 kV tests - ensures reliability in harsh environmental exposure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMA6T28AY | Unidirectional; VBR min = 24.0 V; same clamping (37.8 V) and power rating | Requires correct polarity placement; unsuitable for floating/differential lines | Select when protecting grounded single-ended signals (e.g., microcontroller GPIO) where polarity is fixed |
| SMBJ28CA | SMB package (DO-214AA); higher 600 W rating but larger footprint; VCL = 45.4 V @ 13.1 A | Lower power density; less suitable for dense PCB layouts in modern ADAS modules | Choose when existing SMB footprint is standardized and higher clamping voltage is acceptable |
Compared with SMA6T28AY and SMBJ28CA, SMA6T28CAY offers true bidirectional symmetry for differential signaling, lower clamping voltage (37.8 V vs. 45.4 V), and SMA's smaller footprint - making it optimal for space-constrained 24 V automotive data links requiring polarity-agnostic surge immunity.
Availability
SMA6T28CAY is available at Aetrix Electronics and suitable for automotive electronic control units, ADAS camera power supplies, commercial vehicle CAN networks, and body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SMA6T28CAY 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.
SMA6T28CAY belongs to the SMA6TY Transil™ series - engineered specifically for AEC-Q101-compliant transient suppression in 12 V/24 V automotive subsystems, emphasizing low leakage, high Tj, and full ISO 7637-2/ISO 10605 compliance.
FAQ
Is SMA6T28CAY suitable for 12 V automotive systems?
No - SMA6T28CAY is optimized for 24 V nominal systems. Its 28.1 V minimum breakdown voltage provides adequate margin above 24 V battery rails while avoiding false triggering during normal operation. For 12 V systems, SMA6T15CAY (VBR = 12.8–15.8 V) is recommended to ensure proper clamping headroom and avoid leakage-induced power loss.
What is the maximum surge current SMA6T28CAY can handle at 8/20 µs waveform?
At 8/20 µs, SMA6T28CAY supports up to 80 A peak pulse current (derived from 4 kW peak power rating and 44.3 V clamping voltage). This exceeds ISO 7637-2 Pulse 3b requirements and supports robust protection against lightning-induced surges in vehicle external harnesses.
Does SMA6T28CAY require derating at elevated ambient temperatures?
Yes - peak pulse power must be derated linearly above 25 °C ambient. At 85 °C, maximum 10/1000 µs power drops to ~420 W (70% of 600 W), per Figure 3 in DS6931. Designers must verify clamping voltage remains below protected IC limits using VCL(Tj) = VCL(25 °C) × [1 + αT × (Tj − 25)], where αT = 9.6 × 10−4/°C.
Can SMA6T28CAY be used in parallel for higher power handling?
No - paralleling TVS diodes is not recommended due to mismatched VBR tolerances (±5%) causing uneven current sharing and premature failure of the lower-breakdown unit. For >600 W requirements, select a single higher-rated device such as SMA6T33CAY or consider staged protection with series impedance.
SMA6T28CAY 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:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 24V
- Voltage - Breakdown (Min):
- 26.7V
- Voltage - Clamping (Max) @ Ipp:
- 44.3V
- Current - Peak Pulse (10/1000µs):
- 80A (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)
SMA6T28CAY FAQ
1.How can I place an order for SMA6T28CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA6T28CAY 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 SMA6T28CAY reliable?
The price and inventory of SMA6T28CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA6T28CAY is usually 5 days.
3.What payment methods are accepted for SMA6T28CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA6T28CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA6T28CAY?
SMA6T28CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA6T28CAY 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 SMA6T28CAY?
For technical support, including SMA6T28CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA6T28CAY requirements.
6.How does Aetrix verify that SMA6T28CAY is sourced from the original manufacturer or authorized distributors?
All SMA6T28CAY 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 SMA6T28CAY meets industry standards.
7.What is the process for return or replacement of SMA6T28CAY?
All SMA6T28CAY units undergo pre-shipment inspection (PSI). If there is an issue with SMA6T28CAY, 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 SMA6T28CAY part is unused and in its original packaging.
Return procedure for SMA6T28CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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