My Inquiry
My Account
STMicroelectronics SM6F8.5AY
- Part No.:
- SM6F8.5AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- SOD-128
- Datasheet:
-
SM6F8.5AY.pdf
- Description:
- TVS DIODE 8.5VWM 19.5V SOD128FLT
- Quantity:
- Payment:
- Shipping:
Inventory:6,000
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SM6F8.5AY from STMicroelectronics is an AEC-Q101-qualified unidirectional automotive TVS diode in SOD128 Flat package, designed to clamp transient surges up to 14.4 V at 41.7 A (10/1000 µs), with 8.5 V stand-off voltage, 0.2 µA leakage at 25 °C, and 175 °C maximum junction temperature - deployed for ISO 7637-2 pulse protection on 12 V battery lines.
For engineers reviewing the SM6F8.5AY datasheet, SM6F8.5AY pinout, SM6F8.5AY application, or SM6F8.5AY equivalent, key selection criteria include clamping voltage (14.4 V @ 41.7 A), dynamic resistance (0.096 Ω), high-temperature power derating (240 W @ 175 °C), and compliance with ISO 10605 ±30 kV ESD and ISO 7637-2 Pulse 1/2a/3a/3b.
Technical Context
This TVS diode uses planar silicon technology to achieve low leakage (<1 µA at 85 °C) and stable breakdown behavior across -55 °C to +175 °C operating range. Its unidirectional configuration enables reverse-biased surge suppression on positive-rail automotive circuits without forward conduction during normal operation.
Clamping performance is defined by VCL = VBR + RD × IPP, where measured dynamic resistance (0.096 Ω at 10/1000 µs) directly determines voltage overshoot under surge current. The device meets IEC 61000-4-4 Level 4 (±4 kV) and exceeds ISO 10605 Level 4 for both air and contact discharge.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRWM) | 8.5 V - Maximum continuous reverse voltage before significant leakage; sets minimum system operating margin. |
| Breakdown Voltage (VBR) | 9.4–10.4 V @ 1 mA - Confirmed avalanche onset range; ensures reliable triggering before downstream IC damage. |
| Clamping Voltage (VCL) | 14.4 V @ 41.7 A (10/1000 µs) - Peak voltage seen by protected circuit during worst-case surge; critical for 12 V rail compatibility. |
| Peak Pulse Power (PPP) | 600 W @ 10/1000 µs, 240 W @ 175 °C - Thermal capability limit defining safe single-pulse energy absorption at max junction temperature. |
| Leakage Current (IRM) | 0.2 µA @ 25 °C, 1 µA @ 85 °C - Low reverse leakage preserves battery life and avoids false triggers in always-on modules. |
| Dynamic Resistance (RD) | 0.096 Ω @ 10/1000 µs - Quantifies voltage rise per amp of surge current; enables precise clamping prediction. |
| ESD Withstand (ISO 10605) | ±30 kV (air & contact, C = 330 pF/R = 330 Ω) - Exceeds automotive ESD immunity requirements for infotainment and body control units. |
Pinout & Package
SOD128 Flat package: surface-mount, 2-terminal, lead-free matte tin-plated leads, JEDEC-registered outline, IPC7531 footprint compliant. Dimensions: 4.7 mm × 2.4 mm × 1.0 mm (L × W × H), 28 mg weight.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked end) | Surge current sink node | Connected to protected line (e.g., CAN_H, LIN, or 12 V supply); conducts avalanche current to ground during overvoltage. |
| Anode | Reference / ground return | Typically tied to chassis or system ground; completes low-inductance path for transient energy dissipation. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood and cabin applications including temperature cycling, humidity bias, and mechanical shock. |
| 175 °C junction rating | Enables placement near heat sources (e.g., engine control units) without derating loss; supports extended lifetime in harsh environments. |
| Low dynamic resistance (0.096 Ω) | Minimizes clamping voltage overshoot under fast transients, improving protection margin for 5 V or 3.3 V downstream logic. |
| ISO 7637-2 Pulse 1/2a/3a/3b compliance | Rated for -150 V (Pulse 1), +112 V (Pulse 2a), -220 V (Pulse 3a), +150 V (Pulse 3b) on 12 V systems - covers all major automotive load dump and inductive switching events. |
| Matte tin lead finish | Ensures solderability per J-STD-002/E3 and whisker resistance per JESD201 Class 2 - critical for long-term reliability in automated assembly. |
Applications
| Automotive Body Control Module (BCM) | Infotainment Power Input Protection |
|---|---|
Use Scenario: Protects 12 V input rails feeding microcontrollers and CAN transceivers against load dump and alternator ripple. IC Role / Device Role: Unidirectional TVS clamping device placed between battery feed and DC-DC converter input. Use Value: Limits transient voltage to ≤14.4 V, preventing latch-up or gate oxide damage in 16 V-rated input regulators. |
Use Scenario: Shields USB-C PD and display power supplies from ESD and ignition noise in center-stack head units. IC Role / Device Role: Primary ESD suppressor on 12 V auxiliary input, upstream of buck converters and LDOs. Use Value: Absorbs ±30 kV contact discharge per ISO 10605 without degradation, maintaining signal integrity for audio/video interfaces. |
| Electric Power Steering (EPS) Sensor Interface | Telematics Control Unit (TCU) CAN Bus Line |
Use Scenario: Guards analog sensor supply lines (e.g., torque sensor VREF) against coupled transients from motor drivers. IC Role / Device Role: Low-leakage TVS on precision 5 V reference rail, minimizing offset drift at 85 °C. Use Value: Delivers <1 µA leakage at 85 °C, preserving ADC accuracy and reducing calibration drift over vehicle lifetime. |
Use Scenario: Protects CAN_H/CAN_L differential pair against ESD and battery disconnection spikes in cellular-connected TCUs. IC Role / Device Role: Unidirectional TVS on CAN_H line referenced to chassis ground, with matched layout to preserve common-mode rejection. Use Value: Clamps to 14.4 V within 1 ns, preventing CAN transceiver saturation and bus lockup during ±30 kV ESD events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional automotive TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ8.5A | Higher VCL = 15.0 V @ 38.2 A; lower PPP = 400 W; SMA package (larger footprint, higher thermal resistance). | Limited to ambient-temp-only applications; not rated for 175 °C operation or ISO 7637-2 Pulse 3b. | Choose only if cost sensitivity outweighs thermal and automotive compliance requirements. |
| TPSMD8.5A | VCL = 14.5 V @ 41.0 A; same SOD128 footprint; but only AEC-Q200 qualified (not Q101), no ISO 7637-2 Pulse 1/3a validation. | Acceptable for non-safety-critical interior modules but excluded from powertrain and ADAS domains. | Select when full AEC-Q101 and ISO 7637-2 certification is not mandated by OEM specification. |
Compared with SMAJ8.5A and TPSMD8.5A, SM6F8.5AY uniquely combines 175 °C operation, 600 W peak power, and full ISO 7637-2 Pulse 1/2a/3a/3b validation in a compact SOD128 package - making it the only option qualified for under-hood engine control and safety-critical EPS systems.
Availability
SM6F8.5AY is available at Aetrix Electronics and suitable for automotive body control modules, telematics units, electric power steering systems, and infotainment power inputs requiring stable component supply across multi-year production cycles.
Supply support for SM6F8.5AY 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.
The SM6FY series belongs to ST's automotive protection portfolio, engineered specifically for robust transient suppression in 12 V and 24 V vehicle electrical architectures - targeting design-in for powertrain, chassis, and ADAS subsystems.
FAQ
What is the maximum clamping voltage of SM6F8.5AY under a 10/1000 µs surge?
The maximum clamping voltage is 14.4 V at 41.7 A for a 10/1000 µs waveform, measured at Tj = 25 °C. This value increases with junction temperature per the coefficient αT = 7.3 × 10−4/°C, reaching ~15.1 V at 175 °C using the formula VCL(Tj) = VCL(25 °C) × [1 + αT × (Tj − 25)].
Can SM6F8.5AY be used in bidirectional configurations?
No - SM6F8.5AY is strictly unidirectional and must be installed with cathode toward the protected line. Bidirectional protection requires separate devices like SMBJ8.5CA or dual-diode arrays; using this part in reverse orientation risks permanent breakdown due to lack of forward surge rating.
Does SM6F8.5AY meet lead-free soldering standards?
Yes - it features matte tin-plated leads compliant with J-STD-020 MSL Level 1, J-STD-002 Class 3 solderability, and JEDEC reflow profile up to 245 °C peak. The recommended profile includes ramp rates ≤3 °C/s and 60–90 s above 217 °C, matching standard lead-free PCB assembly processes.
How does SM6F8.5AY compare to SM6F10AY in terms of system-level protection margin?
SM6F8.5AY provides tighter clamping (14.4 V vs. 17.0 V) and lower stand-off voltage (8.5 V vs. 10 V), making it better suited for protecting 12 V systems with narrow voltage tolerances - such as those powering 16 V-input DC-DCs or CAN transceivers with 15 V absolute max ratings. Its lower VRWM also reduces risk of false triggering during cold-crank dips.
SM6F8.5AY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- SOD-128
- Series:
- SM6F
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 8.5V (Max)
- Voltage - Breakdown (Min):
- 9.4V
- Voltage - Clamping (Max) @ Ipp:
- 19.5V
- Current - Peak Pulse (10/1000µs):
- 205A (8/20µs)
- 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:
- SOD128Flat
SM6F8.5AY FAQ
1.How can I place an order for SM6F8.5AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM6F8.5AY 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 SM6F8.5AY reliable?
The price and inventory of SM6F8.5AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM6F8.5AY is usually 5 days.
3.What payment methods are accepted for SM6F8.5AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM6F8.5AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM6F8.5AY?
SM6F8.5AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM6F8.5AY 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 SM6F8.5AY?
For technical support, including SM6F8.5AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM6F8.5AY requirements.
6.How does Aetrix verify that SM6F8.5AY is sourced from the original manufacturer or authorized distributors?
All SM6F8.5AY 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 SM6F8.5AY meets industry standards.
7.What is the process for return or replacement of SM6F8.5AY?
All SM6F8.5AY units undergo pre-shipment inspection (PSI). If there is an issue with SM6F8.5AY, 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 SM6F8.5AY part is unused and in its original packaging.
Return procedure for SM6F8.5AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM6F8.5AY Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
