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Diodes Incorporated SMF4L85A-7
- Part No.:
- SMF4L85A-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L85A-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:8,856
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Product details
Overview
SMF4L85A-7 from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode with a working peak reverse voltage of 85V, breakdown voltage range 94.4–104V at 1mA, and clamping voltage ≤137V at 2.9A peak surge current. It features <1.0ns response time, IEC61000-4-2 ±30kV ESD protection, and is qualified for automotive-grade reliability per AEC-Q101 in DO-219AA package.
For engineers reviewing the SMF4L85A-7 datasheet, SMF4L85A-7 pinout, SMF4L85A-7 application, or SMF4L85A-7 equivalent, key selection criteria include clamping performance at 2.9A surge, unidirectional polarity confirmation via cathode band marking, thermal resistance (RθJA = 96°C/W), and compatibility with FR-4 PCB layouts using 2 oz. copper pads.
Technical Context
This TVS diode operates as a clamping-type overvoltage protector in DC power rails and signal lines. Its silicon avalanche structure delivers precise breakdown onset at 94.4V (min) and stable clamping up to 137V under 10/1000µs transients, enabling robust protection of downstream ICs against load dump, ISO 7637-2 pulses, and ESD events.
The DO-219AA package supports high-power dissipation (400W peak, 1.0W steady-state) with low thermal resistance to ambient (96°C/W) and junction-to-soldering-point (70°C/W), ensuring reliable operation across –55°C to +175°C ambient conditions without derating below +25°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400W (10/1000µs waveform); sustains single high-energy transients without failure |
| Working Peak Reverse Voltage (VRWM) | 85V; maximum continuous DC or RMS voltage before leakage exceeds 100µA |
| Breakdown Voltage (VBR) | 94.4–104V @ 1mA; defines precise avalanche initiation threshold for clamping |
| Clamping Voltage (VC) | ≤137V @ 2.9A; limits voltage seen by protected circuit during surge |
| ESD Rating | ±30kV air/contact per IEC61000-4-2; eliminates need for external ESD diodes |
| Response Time | <1.0ns (unidirectional); ensures clamping activation before transient propagates |
| Operating Temperature | –55°C to +175°C; supports under-hood automotive and industrial environments |
Pinout & Package
Package: DO-219AA - surface-mount, molded plastic, halogen-free, RoHS-compliant, 0.016g weight, moisture sensitivity level 1. Cathode band denotes unidirectional polarity; anode and cathode terminals are co-planar on opposite ends of the rectangular body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry point during forward conduction | Connected to protected line (e.g., battery rail); must be routed with low-inductance trace |
| Cathode | Current exit point during reverse-biased clamping | Connected to ground reference; requires low-impedance path to minimize clamping overshoot |
Key Features
| Feature | Design Value |
|---|---|
| Automotive-grade qualification | AEC-Q101 qualified; manufactured in IATF 16949 certified facilities for mission-critical systems |
| High ESD immunity | ±30kV contact/air discharge; protects USB, CAN, LIN, and sensor interfaces without additional components |
| Low clamping ratio | VC/VRWM = 1.61; minimizes overvoltage stress on protected ICs compared to higher-ratio TVS devices |
| Thermal robustness | RθJA = 96°C/W on 1"×1" FR-4 board; enables operation at full power without heatsinking |
| Green packaging | Halogen- and antimony-free (<900ppm Br/Cl, <1000ppm Sb); meets automotive environmental compliance requirements |
Applications
| Automotive Power Rail Protection | Battery Management Systems (BMS) |
|---|---|
Use Scenario: Protecting 12V/24V vehicle electronics (ECUs, lighting modules) against load dump transients per ISO 7637-2 Pulse 5a. IC Role / Device Role / Timing Role: Clamping diode placed between battery input and DC-DC converter input stage. Use Value: Limits voltage to ≤137V during 100V/350ms transients, preventing MOSFET gate oxide rupture and regulator latch-up. | Use Scenario: Safeguarding cell monitor ICs and coulomb counters in EV/HEV battery packs exposed to hot-plug and charge/discharge switching noise. IC Role / Device Role / Timing Role: Unidirectional TVS on each cell tap and main pack voltage sense line. Use Value: Suppresses >1kV fast transients from relay bounce and contact arcing while maintaining <100µA leakage at 85V nominal pack voltage. |
| Industrial Sensor Interface Protection | Telecom Power Input Stage |
Use Scenario: Shielding 4–20mA loop-powered sensors and RS-485 transceivers from induced surges in factory automation wiring. IC Role / Device Role / Timing Role: TVS placed at connector entry point, upstream of signal conditioning and isolation stages. Use Value: Responds in <1ns to clamp 4kV EFT bursts to <137V, preserving ADC reference stability and isolator integrity. | Use Scenario: Guarding PoE-powered equipment (IP cameras, access points) against lightning-induced surges on 48V DC input lines. IC Role / Device Role / Timing Role: Primary clamping device on secondary-side DC bus after PoE controller and filter stage. Use Value: Absorbs 400W surge energy without degradation, maintaining ≤137V clamping to protect DC-DC controllers and Ethernet PHYs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ85A | Lower peak power (400W same), but SMA package (DO-214AC) has RθJA = 110°C/W vs. 96°C/W; 30% larger footprint | Less suitable for high-density automotive PCBs where thermal margin and space are constrained | Select when legacy SMA layout exists and thermal derating is acceptable |
| TPSMD85A | Same DO-219AA package, but lower clamping voltage (128V @ 2.9A) and tighter VBR tolerance (94.4–99.9V) | Better for ultra-sensitive 85V-rated loads requiring lower clamping overshoot | Prefer when protecting 85V-rated GaN FETs or precision analog front-ends |
Compared with SMAJ85A and TPSMD85A, SMF4L85A-7 offers optimal balance of thermal performance (96°C/W), compact DO-219AA footprint, and industry-standard 137V clamping-making it ideal for new automotive and industrial designs prioritizing reliability and board area efficiency.
Availability
SMF4L85A-7 is available at Aetrix Electronics and suitable for automotive ECUs, battery management systems, industrial sensor nodes, and telecom power supplies requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SMF4L85A-7 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 integrated circuits, specializing in high-reliability protection, power management, and signal integrity solutions for automotive, industrial, and consumer markets.
The SMF4L series belongs to Diodes' automotive-qualified TVS portfolio, engineered specifically for robust transient suppression in harsh environments-emphasizing low clamping ratio, AEC-Q101 compliance, and green packaging for modern vehicle architectures.
FAQ
What is the polarity configuration of SMF4L85A-7?
SMF4L85A-7 is a unidirectional TVS diode, indicated by the cathode band marking on the DO-219AA package. It conducts only during reverse-biased overvoltage events, with anode connected to the protected line and cathode to ground. This configuration provides superior clamping performance versus bidirectional variants for DC rail protection.
Does SMF4L85A-7 meet automotive qualification standards?
Yes-SMF4L85A-7 is AEC-Q101 qualified and manufactured in IATF 16949 certified facilities. It undergoes rigorous stress testing including HTOL, temperature cycling, and ESD verification, supporting use in engine control units, ADAS modules, and other safety-critical automotive subsystems without additional qualification.
How does the DO-219AA package improve thermal performance over SMA (DO-214AC)?
The DO-219AA package delivers RθJA = 96°C/W on standard FR-4, versus ~110°C/W for SMA packages, due to optimized thermal path geometry and larger copper pad exposure. This 13% lower thermal resistance allows sustained 400W pulse handling at higher ambient temperatures and reduces risk of thermal runaway in dense layouts.
Can SMF4L85A-7 replace older SMF85A variants in existing designs?
Yes-SMF4L85A-7 is a direct drop-in replacement for legacy SMF85A in DO-219AA footprint, offering identical electrical specs and enhanced process controls. Key improvements include tighter VBR distribution (94.4–104V vs. 94–105V), improved ESD robustness (±30kV), and full halogen/antimony-free compliance per automotive green standards.
SMF4L85A-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):
- 85V
- Voltage - Breakdown (Min):
- 94.4V
- Voltage - Clamping (Max) @ Ipp:
- 137V
- Current - Peak Pulse (10/1000µs):
- 2.9A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AA
SMF4L85A-7 FAQ
1.How can I place an order for SMF4L85A-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L85A-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 SMF4L85A-7 reliable?
The price and inventory of SMF4L85A-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L85A-7 is usually 5 days.
3.What payment methods are accepted for SMF4L85A-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L85A-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L85A-7?
SMF4L85A-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L85A-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 SMF4L85A-7?
For technical support, including SMF4L85A-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L85A-7 requirements.
6.How does Aetrix verify that SMF4L85A-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L85A-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 SMF4L85A-7 meets industry standards.
7.What is the process for return or replacement of SMF4L85A-7?
All SMF4L85A-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L85A-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 SMF4L85A-7 part is unused and in its original packaging.
Return procedure for SMF4L85A-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L85A-7 Tags
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ESD9B5.0ST5G
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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onsemi
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Diodes Incorporated
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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