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STMicroelectronics SMB6F28AY
- Part No.:
- SMB6F28AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-221AA, SMB Flat Leads
- Datasheet:
-
SMB6F28AY.pdf
- Description:
- TVS DIODE 28VWM 45.4VC SMBFLAT
- Quantity:
- Payment:
- Shipping:
Inventory:2,112
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Product details
Overview
SMB6F28AY from STMicroelectronics is an AEC-Q101-qualified unidirectional automotive TVS diode in SMB Flat package, designed to clamp transient overvoltages up to 45.4 V (10/1000 µs) at 13.8 A peak pulse current while maintaining low leakage (0.2 µA @ 25 °C), enabling robust protection of 24 V automotive power rails against ISO 7637-2 pulses and IEC 61000-4-2 ESD events.
For engineers reviewing the SMB6F28AY datasheet, SMB6F28AY pinout, SMB6F28AY application, or SMB6F28AY equivalent, this device serves as a high-reliability surge suppressor for battery-supplied ECUs, body control modules, and infotainment power inputs where junction temperature stability up to 175 °C and flat 1 mm profile are critical.
Technical Context
This TVS diode employs planar silicon technology to achieve low dynamic resistance (0.804 Ω at 25 °C) and stable clamping voltage across temperature - VCL increases with junction temperature at αT = 9.8 × 10−4/°C. Its unidirectional configuration provides reverse-biased surge suppression only, requiring correct polarity placement on DC lines.
It meets stringent automotive transient immunity standards: ISO 7637-2 Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V), and exceeds IEC 61000-4-2 Level 4 ESD (±30 kV contact/air) with C = 150 pF/R = 330 Ω and C = 330 pF/R = 330 Ω configurations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 28 V - Maximum continuous reverse operating voltage before breakdown; sets minimum system working voltage margin. |
| Breakdown Voltage (VBR) | 31.1–34.3 V @ IBR = 1 mA - Confirmed voltage range where device enters avalanche conduction; ensures reliable triggering above nominal rail. |
| Clamping Voltage (VCL) | 45.4 V @ IPP = 13.8 A (10/1000 µs) - Peak voltage seen by protected circuit during worst-case surge; defines maximum stress on downstream ICs. |
| Peak Pulse Power (PPP) | 600 W @ Tj = 25 °C (10/1000 µs); 470 W @ Tj = 175 °C - Sustained surge energy handling capability degrades predictably with junction temperature. |
| Leakage Current (IR) | 0.2 µA @ 25 °C, 1 µA @ 85 °C - Ultra-low reverse leakage preserves battery life in always-on automotive modules. |
| Junction Temperature Range | −55 to +175 °C - Enables operation in under-hood environments without derating or thermal shutdown. |
| Package | SMB Flat (JEDEC DO-214AA), 3.3–3.95 mm × 5.2–5.6 mm × 1.1 mm max - Low-profile surface-mount footprint compatible with automated assembly and space-constrained PCB layouts. |
Pinout & Package
SMB6F28AY uses the standard SMB Flat (DO-214AA) two-terminal package: Cathode (marked end) and Anode. The flat, low-profile design (1 mm height) supports high-density routing and thermal management via copper pads per JEDEC footprint recommendation (5.84 mm × 2.07 mm pad pitch).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Marked End) | Surge Current Sink | Connected to protected line; conducts avalanche current to ground during overvoltage events; polarity must match DC rail orientation. |
| Anode | Reference / Ground Return | Typically tied to chassis or power ground; completes surge path; requires low-inductance layout to minimize VCL overshoot. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive-grade reliability including temperature cycling, humidity bias, and mechanical shock - required for ECU front-end protection. |
| Low dynamic resistance (RD) | 0.804 Ω @ 25 °C - Minimizes clamping voltage rise under high-current transients, improving protection margin for 24 V systems. |
| High-temperature operation | Rated up to Tj = 175 °C - Supports placement near heat sources (e.g., power converters) without performance loss or lifetime degradation. |
| Flat 1 mm profile | Height ≤ 1.1 mm - Enables use in ultra-thin modules (e.g., ADAS cameras, LED drivers) where Z-axis clearance is constrained. |
| ESD robustness | ±30 kV contact/air discharge (IEC 61000-4-2, ISO 10605) - Eliminates need for secondary ESD protection in CAN/LIN bus interfaces and sensor inputs. |
Applications
| Body Control Module (BCM) | Infotainment Power Input |
|---|---|
|
Use Scenario: Protecting 24 V supply input of BCM against load dump and alternator transients during vehicle start-stop cycles. IC Role / Device Role / Timing Role: Unidirectional TVS clamps reverse-polarity surges and ISO 7637-2 Pulse 1 (−150 V) to safe levels before they reach MCU and power management ICs. Use Value: Prevents latch-up or permanent damage to 3.3 V/5 V LDOs and microcontrollers during cold-crank conditions where battery voltage dips then spikes. |
Use Scenario: Safeguarding USB-C and HDMI power rails in head unit against ESD events from user interface and cable hot-plug. IC Role / Device Role / Timing Role: Fast-response TVS absorbs ±30 kV ESD strikes (IEC 61000-4-2) within nanoseconds, limiting voltage to <45.4 V at 13.8 A peak. Use Value: Maintains signal integrity and prevents reset or corruption of audio/video processors during field deployment without adding series impedance. |
| ADAS Camera Module | Electric Power Steering (EPS) ECU |
|
Use Scenario: Shielding 12 V imaging sensor supply from ignition noise and ISO 7637-2 Pulse 3b (+150 V) induced by motor actuation. IC Role / Device Role / Timing Role: Stand-off voltage of 28 V allows operation across full automotive battery range (9–16 V) while clamping transients before image sensor analog front-end. Use Value: Ensures zero frame drop or pixel corruption during aggressive steering maneuvers by limiting transient-induced supply droop. |
Use Scenario: Protecting H-bridge gate drivers and current-sense amplifiers in EPS from inductive kickback during motor commutation. IC Role / Device Role / Timing Role: Absorbs repetitive 8/20 µs surges up to 59 A (VCL = 45.4 V) generated by brushed/BLDC motor switching. Use Value: Extends lifetime of MOSFET drivers and eliminates false torque sensor readings caused by voltage spikes coupling into analog sensing paths. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional automotive TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ28A | Same SMB package, but rated for 600 W (10/1000 µs) with VBR = 31.1–34.4 V and VCL = 45.7 V @ 13.7 A - slightly higher clamping and lower leakage (1 µA @ 85 °C vs. 1 µA). | Not AEC-Q101 qualified; intended for industrial/commercial use only - unsuitable for safety-critical automotive modules. | Select SMBJ28A only for non-automotive 24 V systems where qualification is not mandated and cost sensitivity outweighs long-term reliability requirements. |
| 1.5SMC28A | Higher power rating (1500 W), larger SMC package (7.11 mm × 6.22 mm × 2.62 mm), VCL = 43.0 V @ 35 A - lower clamping but incompatible footprint and thermal mass. | Used in heavy-duty truck electronics with higher surge budgets; cannot replace SMB6F28AY without PCB redesign due to size and pad layout mismatch. | Choose 1.5SMC28A only when system-level testing confirms >1 kW surge exposure and board space permits larger package; not a drop-in replacement. |
Compared with SMBJ28A and 1.5SMC28A, SMB6F28AY uniquely combines AEC-Q101 compliance, SMB Flat form factor, and precise 28 V stand-off in a single solution - making it the only choice for volume automotive production where qualification, footprint, and thermal performance are jointly constrained.
Availability
SMB6F28AY is available at Aetrix Electronics and suitable for body control modules, ADAS camera power supplies, infotainment head units, and electric power steering ECUs requiring stable component supply across automotive production lifecycles.
Supply support for SMB6F28AY 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 discrete technologies with vertical manufacturing and broad IP portfolio.
SMB6F28AY belongs to the SMB6FxxAY series - a family of AEC-Q101-qualified unidirectional TVS diodes engineered specifically for ISO 7637-2 and ISO 10605 compliance in 12 V/24 V automotive power networks.
FAQ
What is the maximum clamping voltage of SMB6F28AY under a 10/1000 µs surge?
The maximum clamping voltage is 45.4 V at 13.8 A peak pulse current (10/1000 µs waveform, Tj = 25 °C). This value increases linearly with junction temperature at a coefficient of 9.8 × 10−4/°C, reaching approximately 47.2 V at Tj = 125 °C.
Can SMB6F28AY be used in bidirectional protection circuits?
No - SMB6F28AY is strictly unidirectional and only protects against reverse-polarity transients on positive DC rails. For bidirectional protection (e.g., data lines or AC-coupled signals), a symmetric TVS like SMB6F28CA or SMAJ28CA is required; using SMB6F28AY in reverse bias risks permanent failure.
How does SMB6F28AY's leakage current compare to standard industrial TVS diodes?
At 25 °C, SMB6F28AY exhibits only 0.2 µA leakage - significantly lower than typical industrial SMBJ devices (e.g., SMBJ28A: 1 µA). This ultra-low leakage is achieved via planar process optimization and enables use in always-on automotive modules without measurable battery drain over time.
Is SMB6F28AY compatible with lead-free reflow soldering processes?
Yes - it is qualified for lead-free reflow per J-STD-020 MSL Level 1, with a maximum peak temperature of 245 °C and 60-second dwell time. The matte tin-plated leads meet JESD 22-B102 E3 and MIL-STD-750 Method 2026, ensuring reliable wetting and intermetallic formation without whisker growth.
SMB6F28AY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-221AA, SMB Flat Leads
- Series:
- SMB6FxxAY
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 28V (Max)
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.4V
- Current - Peak Pulse (10/1000µs):
- 13.8A
- Power - Peak Pulse:
- 600W
- 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:
- SMBflat
SMB6F28AY FAQ
1.How can I place an order for SMB6F28AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB6F28AY 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 SMB6F28AY reliable?
The price and inventory of SMB6F28AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMB6F28AY is usually 5 days.
3.What payment methods are accepted for SMB6F28AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB6F28AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB6F28AY?
SMB6F28AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB6F28AY 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 SMB6F28AY?
For technical support, including SMB6F28AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB6F28AY requirements.
6.How does Aetrix verify that SMB6F28AY is sourced from the original manufacturer or authorized distributors?
All SMB6F28AY 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 SMB6F28AY meets industry standards.
7.What is the process for return or replacement of SMB6F28AY?
All SMB6F28AY units undergo pre-shipment inspection (PSI). If there is an issue with SMB6F28AY, 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 SMB6F28AY part is unused and in its original packaging.
Return procedure for SMB6F28AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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