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STMicroelectronics SMB6F8.5AY
- Part No.:
- SMB6F8.5AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-221AA, SMB Flat Leads
- Datasheet:
-
SMB6F8.5AY.pdf
- Description:
- TVS DIODE 8.5VWM 14.4VC SMBFLAT
- Quantity:
- Payment:
- Shipping:
Inventory:4,990
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Product details
Overview
SMB6F8.5AY from STMicroelectronics is an AEC-Q101-qualified unidirectional automotive TVS diode in SMB Flat package, designed to clamp transient overvoltages up to 14.4 V (10/1000 µs) at 41.7 A peak pulse current while maintaining low leakage (1 µA @ 85 °C) and operating up to 175 °C junction temperature. It protects 12 V automotive power rails against ISO 7637-2 pulses (Pulse 1: −150 V; Pulse 2a: +112 V) and exceeds ISO 10605 ESD immunity (±30 kV contact/air).
For engineers reviewing the SMB6F8.5AY datasheet, SMB6F8.5AY pinout, SMB6F8.5AY application, or SMB6F8.5AY equivalent, this device is selected for robust front-end surge suppression in automotive body control modules, infotainment power supplies, and ADAS sensor interfaces where flat-profile mounting, high-temperature reliability, and precise 8.5 V stand-off voltage are critical.
Technical Context
This TVS operates as a unidirectional clamping device with a nominal reverse stand-off voltage (VRM) of 8.5 V, breakdown voltage (VBR) of 9.4–10.4 V at 1 mA, and clamping voltage (VCL) of 14.4 V at 41.7 A (10/1000 µs). Its planar silicon construction enables low dynamic resistance (RD = 0.096 Ω) and stable performance across −55 °C to +175 °C junction temperature range.
It complies with ISO 7637-2 (Pulse 1, 2a, 3a, 3b), ISO 10605 (±30 kV), and IEC 61000-4-4 Level 4 (±4 kV), and is rated for 600 W peak pulse power (10/1000 µs) and 4 kW (8/20 µs) - validated under JEDEC-standard test conditions with Tj initial = 25 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 8.5 V - blocks normal 12 V system operation while triggering only during transients ≥9.4 V. |
| Clamping Voltage (VCL) | 14.4 V at 41.7 A (10/1000 µs) - limits downstream IC stress to safe levels during load dump or inductive switching. |
| Peak Pulse Power | 600 W (10/1000 µs) - sustains automotive-level surges without thermal runaway at Tj ≤175 °C. |
| Leakage Current | 1 µA @ 85 °C - minimizes quiescent power loss in always-on vehicle subsystems. |
| Junction Temperature Range | −55 °C to +175 °C - supports under-hood placement near engine control units and transmission ECUs. |
| Package Height | 1.0 mm max - enables low-profile PCB layout in space-constrained automotive modules. |
| ESD Rating | ±30 kV (ISO 10605, C = 330 pF/R = 330 Ω) - protects CAN/LIN transceivers and microcontroller I/O pins from human-body-model events. |
Pinout & Package
SMB6F8.5AY uses the JEDEC-registered SMB Flat package (DO-214AA), measuring 3.95 mm × 5.60 mm × 1.10 mm with matte tin-plated leads compliant with J-STD-002 and IPC7531 footprint standards. The flat profile enables automated optical inspection and reduces board warpage risk during reflow.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Marked Band) | Transient Clamp Output | Connected to protected line (e.g., battery rail); sinks surge current to ground during overvoltage events. |
| Anode | Reference Terminal | Connected to system ground; completes clamping path and defines unidirectional conduction direction. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive use across temperature, humidity, vibration, and lifetime stress tests per JESD47. |
| Low dynamic resistance (RD) | 0.096 Ω - ensures rapid voltage clamping with minimal overshoot during fast transients (e.g., ISO 7637-2 Pulse 3b). |
| High-temperature stability | Specified performance maintained up to Tj = 175 °C - eliminates derating in engine bay applications. |
| Flat SMB package | 1.0 mm height - allows stacking with adjacent components and improves airflow in sealed enclosures. |
| Matte tin lead finish | Complies with JESD22-B102 E3 and MIL-STD-750 Method 2026 - ensures reliable solder wetting and long-term intermetallic integrity. |
Applications
| Body Control Module (BCM) | Infotainment Power Supply |
|---|---|
Use Scenario: Protects 12 V input rail of BCM from load dump and alternator ripple during ignition cycling. IC Role / Device Role / Timing Role: Unidirectional transient voltage suppressor placed between battery feed and DC-DC converter input. Use Value: Clamps ISO 7637-2 Pulse 1 (−150 V) to ≤14.4 V, preventing damage to LDO regulators and microcontrollers. |
Use Scenario: Shields USB-C PD and display power rails in head unit against ESD and hot-swap transients. IC Role / Device Role / Timing Role: Front-end TVS on 12 V auxiliary input before buck converter and USB controller. Use Value: Withstands ±30 kV ISO 10605 discharges without degradation, preserving signal integrity on high-speed data lines. |
| ADAS Camera Module | Electric Power Steering (EPS) |
Use Scenario: Safeguards image sensor and serializer ICs from cable-induced surges in rear-view camera harnesses. IC Role / Device Role / Timing Role: Localized TVS on FAKRA connector input, co-located with filtering capacitors. Use Value: Limits clamping voltage to 14.4 V during 8/20 µs transients, avoiding latch-up in 3.3 V MIPI CSI-2 receivers. |
Use Scenario: Guards motor driver gate drivers and MCU power rails against inductive kickback from steering column motors. IC Role / Device Role / Timing Role: Bidirectional protection not required; unidirectional SMB6F8.5AY used on low-side switch return path. Use Value: Maintains <1 µA leakage at 85 °C, eliminating false fault detection in torque-sensing analog front-ends. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional automotive TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ8.5A | Same VRM (8.5 V), but lower peak power (600 W vs. SMB6F8.5AY's 600 W @ 10/1000 µs; identical rating), higher VCL (15.0 V vs. 14.4 V), same SMB package. | Marginally higher clamping voltage increases stress on downstream 16 V-rated components. | Select when legacy design uses SMBJ series footprint and minor VCL increase is acceptable. |
| TPSMA6L8.5A | Lower leakage (0.5 µA @ 25 °C vs. 20 µA), same VRM, but lower Tj max (150 °C vs. 175 °C) and no AEC-Q101 certification. | Not qualified for under-hood use; limited to cabin-mounted modules with ambient <85 °C. | Choose only for non-automotive industrial applications requiring tighter leakage spec and lower cost. |
Compared with SMBJ8.5A and TPSMA6L8.5A, SMB6F8.5AY delivers superior high-temperature reliability (175 °C), lower clamping voltage, and full AEC-Q101 compliance - making it the preferred choice for safety-critical automotive power rail protection where thermal margin and transient precision are non-negotiable.
Availability
SMB6F8.5AY is available at Aetrix Electronics and suitable for automotive body control modules, infotainment systems, ADAS camera interfaces, and electric power steering ECUs requiring stable component supply with full AEC-Q101 traceability and extended temperature support.
Supply support for SMB6F8.5AY 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, delivering automotive-grade analog, power, and microcontroller solutions since 1987.
SMB6F8.5AY belongs to ST's SMB6FY automotive TVS family, engineered specifically for ISO 7637-2 and ISO 10605 compliance in 12 V vehicle architectures - emphasizing low-profile packaging, high-temperature resilience, and zero derating up to 175 °C.
FAQ
What is the maximum clamping voltage for SMB6F8.5AY under ISO 7637-2 Pulse 1 conditions?
The SMB6F8.5AY clamps to 14.4 V at 41.7 A (10/1000 µs), which directly applies to ISO 7637-2 Pulse 1 (−150 V, 50 Ω source impedance). Its low dynamic resistance (0.096 Ω) ensures consistent clamping performance even at elevated junction temperatures up to 175 °C, verified per DS12412 Rev 1 test methodology.
Does SMB6F8.5AY require derating above 25 °C ambient temperature?
No derating is required for peak pulse power up to 175 °C junction temperature. Figure 3 in DS12412 shows full 600 W capability maintained at Tj = 175 °C for VRM < 100 V devices. Thermal design must ensure Rth(j-a) stays within limits via recommended copper area (Figure 11) and FR4 PCB layout.
Can SMB6F8.5AY be used in bidirectional configurations?
No - SMB6F8.5AY is unidirectional only, with cathode marked band. For bidirectional protection, ST offers the SMB6F8.5CA variant (center-tap configuration). Using two unidirectional devices back-to-back is not recommended due to mismatched VBR and potential failure asymmetry during differential transients.
What is the marking code for SMB6F8.5AY on the package?
The top-side marking is "7APY", as specified in Table 6 of DS12412 Rev 1. This 4-character code uniquely identifies the SMB6F8.5AY variant within the SMB6FY series and is laser-etched on the cathode-end surface of the SMB Flat body.
SMB6F8.5AY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-221AA, SMB Flat Leads
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 8.5V
- Voltage - Breakdown (Min):
- 9.4V
- Voltage - Clamping (Max) @ Ipp:
- 14.4V
- Current - Peak Pulse (10/1000µs):
- 41.7A
- 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
SMB6F8.5AY FAQ
1.How can I place an order for SMB6F8.5AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB6F8.5AY 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 SMB6F8.5AY reliable?
The price and inventory of SMB6F8.5AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMB6F8.5AY is usually 5 days.
3.What payment methods are accepted for SMB6F8.5AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB6F8.5AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB6F8.5AY?
SMB6F8.5AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB6F8.5AY 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 SMB6F8.5AY?
For technical support, including SMB6F8.5AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB6F8.5AY requirements.
6.How does Aetrix verify that SMB6F8.5AY is sourced from the original manufacturer or authorized distributors?
All SMB6F8.5AY 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 SMB6F8.5AY meets industry standards.
7.What is the process for return or replacement of SMB6F8.5AY?
All SMB6F8.5AY units undergo pre-shipment inspection (PSI). If there is an issue with SMB6F8.5AY, 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 SMB6F8.5AY part is unused and in its original packaging.
Return procedure for SMB6F8.5AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB6F8.5AY Tags
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