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Diodes Incorporated SMF4L8.5AQ-7
- Part No.:
- SMF4L8.5AQ-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L8.5AQ-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:3,611
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Product details
Overview
SMF4L8.5AQ from Diodes Incorporated is a unidirectional transient voltage suppressor (TVS) diode designed for robust overvoltage protection in automotive and industrial power rails. It features a 8.5V working peak reverse voltage (VRWM), 9.44V minimum breakdown voltage (VBR), 14.4V maximum clamping voltage (VC) at 27.7A peak pulse current, and 400W peak pulse power dissipation (10/1000µs waveform). It is AEC-Q101 qualified and used on battery contacts and 12V supply lines.
For engineers reviewing the SMF4L8.5AQ datasheet, SMF4L8.5AQ pinout, SMF4L8.5AQ application, or SMF4L8.5AQ equivalent, key selection criteria include clamping performance under 27.7A surge, unidirectional polarity for DC rail protection, DO-219AA package compatibility with high-density layouts, and compliance with IEC61000-4-2 ±30kV ESD requirements.
Technical Context
This TVS operates as a unidirectional clamp, conducting only during negative transients relative to its anode–cathode orientation. Its fast response time (<1.0ns from 0V to VBR) ensures suppression before downstream ICs experience overstress. The device uses silicon avalanche junction technology optimized for low dynamic impedance and stable clamping across temperature.
It is rated for 400W peak pulse power per the 10µs × 1000µs standard waveform, with thermal resistance RθJA = 96°C/W on a 1"×1" FR-4 board. Its 1.0W steady-state power rating and -55°C to +175°C operating range support under-hood automotive deployment.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 8.5V - Maximum continuous reverse voltage before leakage exceeds 10μA; sets upper limit for protected DC rail. |
| VBR (min) | 9.44V @ 1mA - Ensures reliable turn-on above normal operating voltage, preventing false triggering. |
| VC (max) | 14.4V @ 27.7A - Clamped voltage seen by downstream circuitry during worst-case surge; defines safe margin for 12V systems. |
| PPK | 400W (10/1000µs) - Sustains high-energy transients such as ISO 7637-2 Pulse 1/2a without degradation. |
| ESD Rating | ±30kV contact & air (IEC61000-4-2) - Protects against human-body-model and system-level electrostatic discharge events. |
| Package | DO-219AA - Surface-mount, 2.8mm × 1.9mm footprint with 0.6mm lead length; enables compact, automated assembly. |
| AEC-Q101 | Qualified - Validated for automotive use including temperature cycling, HTRB, and ESD stress per AEC specification. |
Pinout & Package
Package: DO-219AA - molded plastic, halogen-free, RoHS-compliant surface-mount package with matte tin-plated copper alloy leads. Cathode band denotes unidirectional polarity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry point during reverse-biased clamping | Connected to protected line (e.g., battery+); conducts surge current toward ground when VC exceeded. |
| Cathode | Current exit point during clamping; marked with band | Connected to ground reference; establishes fixed polarity for DC rail protection; prevents forward conduction in normal operation. |
Key Features
| Feature | Design Value |
|---|---|
| 400W Peak Pulse Power | Withstands ISO 7637-2 Pulse 5a (load dump) surges up to 14.4V clamping at 27.7A without failure. |
| Ultra-Fast Response Time | <1.0ns turn-on delay ensures clamping initiates before sensitive microcontrollers or CAN transceivers are exposed to overvoltage. |
| AEC-Q101 Qualification | Validated for automotive under-hood environments including 1000hr HTOL, temperature cycling (-55°C to +175°C), and mechanical shock. |
| Low Capacitance | Typical junction capacitance <100pF at 0V (per family data) - avoids signal integrity issues on medium-speed lines like LIN or analog sensors. |
| Green Construction | Halogen- and antimony-free molding compound (Br+Cl <1500ppm, Sb <1000ppm) meets automotive OEM environmental mandates. |
Applications
| Automotive Body Control Module (BCM) | Industrial 24V PLC Input Stage |
|---|---|
Use Scenario: Protecting 12V power input of BCM from load dump and jump-start transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery+ and ground, clamping surges before they reach PMIC and MCU power rails. Use Value: Limits voltage to ≤14.4V during 27.7A transients, preserving 12V-rated regulators and ensuring system reset-free operation. | Use Scenario: Safeguarding digital input terminals of programmable logic controllers against field-wiring induced surges. IC Role / Device Role / Timing Role: Primary overvoltage clamp on 24V optocoupler input side, absorbing energy from inductive load switching. Use Value: Maintains input logic threshold integrity by clamping transients within 1ns, preventing false triggering or latch-up in isolation circuitry. |
| Automotive Infotainment Power Supply | Smart Sensor Node Battery Interface |
Use Scenario: Shielding USB-C PD controller and display power path from battery-line transients during vehicle ignition. IC Role / Device Role / Timing Role: First-line TVS on main 12V input rail upstream of buck converters and LDOs feeding SoC and audio codecs. Use Value: Delivers 400W surge handling with minimal PCB area (DO-219AA), enabling compact front-end protection without derating. | Use Scenario: Protecting lithium-ion battery monitoring ICs from ESD events during connector mating/unmating. IC Role / Device Role / Timing Role: Bidirectional-capable variant not used; this unidirectional part guards battery+ to system ground path against contact ESD. Use Value: Provides ±30kV IEC61000-4-2 immunity while maintaining <10μA leakage at 8.5V, minimizing battery drain in always-on nodes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ8.5A | DO-214AC package; higher RθJA (110°C/W); 400W rating same; VRWM = 8.5V, VC = 14.4V @ 27.7A | Larger footprint (4.5mm × 2.7mm vs. 2.8mm × 1.9mm); less suitable for ultra-dense automotive modules | Select SMAJ8.5A only if legacy layout or thermal mass allows larger package; SMF4L8.5AQ preferred for space-constrained designs. |
| TPSMA6L8.5A | DO-214AC; lower leakage (IR = 1μA max @ VRWM); identical VRWM/VC/PPK; AEC-Q101 qualified | Same package size as SMAJ8.5A; slightly tighter leakage spec but no advantage in clamping speed or thermal performance | Choose TPSMA6L8.5A only when sub-1μA leakage is mandatory; SMF4L8.5AQ offers better board-area efficiency and equivalent surge capability. |
Compared with SMAJ8.5A and TPSMA6L8.5A, SMF4L8.5AQ delivers identical electrical protection specs in a 45% smaller footprint (DO-219AA), enabling higher routing density and improved thermal coupling to PCB copper, critical for automotive ECU miniaturization.
Availability
SMF4L8.5AQ is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC input protection, and smart sensor battery interfaces requiring stable component supply across extended production lifecycles.
Supply support for SMF4L8.5AQ 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and the Americas.
The SMF4L series belongs to Diodes' AEC-Q101-qualified TVS portfolio, engineered specifically for automotive power rail protection where small size, high surge capability, and long-term reliability under thermal stress are mandatory.
FAQ
What is the maximum clamping voltage of SMF4L8.5AQ at its rated peak pulse current?
The maximum clamping voltage (VC) is 14.4V at 27.7A peak pulse current (10/1000µs waveform), measured per JEDEC standards. This value guarantees that downstream components see no more than 14.4V during worst-case surge events, making it suitable for protecting 12V-rated ICs with adequate voltage margin.
Is SMF4L8.5AQ suitable for bidirectional signal line protection?
No - SMF4L8.5AQ is unidirectional, with cathode band marking indicating polarity-sensitive installation. For bidirectional protection (e.g., data lines), the bi-directional variant SMF4L8.5CAQ must be used. Using SMF4L8.5AQ on AC or symmetrical signal paths risks forward conduction and failure.
How does the DO-219AA package improve thermal performance over DO-214AC?
The DO-219AA package has lower thermal resistance: RθJA = 96°C/W versus ~110°C/W for DO-214AC, due to shorter internal leads and optimized die attach. On a standard 1"×1" FR-4 board, this enables ~15% higher sustained power handling and faster heat dissipation during repetitive surge events.
Does SMF4L8.5AQ require derating at elevated ambient temperatures?
Yes - peak pulse power must be linearly derated above +25°C per Figure 1 in DS43393. At +85°C ambient, maximum PPK drops to ~280W (70% of 400W). Designers must apply this derating when specifying protection for under-hood applications where ambient may exceed 70°C.
SMF4L8.5AQ-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- DO-219AA
- Series:
- SMF4L
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 8.5V
- Voltage - Breakdown (Min):
- 9.44V
- Voltage - Clamping (Max) @ Ipp:
- 14.4V
- Current - Peak Pulse (10/1000µs):
- 27.7A
- Power - Peak Pulse:
- 400W
- 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:
- DO-219AA
SMF4L8.5AQ-7 FAQ
1.How can I place an order for SMF4L8.5AQ-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L8.5AQ-7 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 SMF4L8.5AQ-7 reliable?
The price and inventory of SMF4L8.5AQ-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L8.5AQ-7 is usually 5 days.
3.What payment methods are accepted for SMF4L8.5AQ-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L8.5AQ-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L8.5AQ-7?
SMF4L8.5AQ-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L8.5AQ-7 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 SMF4L8.5AQ-7?
For technical support, including SMF4L8.5AQ-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L8.5AQ-7 requirements.
6.How does Aetrix verify that SMF4L8.5AQ-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L8.5AQ-7 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 SMF4L8.5AQ-7 meets industry standards.
7.What is the process for return or replacement of SMF4L8.5AQ-7?
All SMF4L8.5AQ-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L8.5AQ-7, 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 SMF4L8.5AQ-7 part is unused and in its original packaging.
Return procedure for SMF4L8.5AQ-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L8.5AQ-7 Tags
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