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Diodes Incorporated SMF4L20A-7
- Part No.:
- SMF4L20A-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L20A-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:8,920
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Product details
Overview
SMF4L20A-7 from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) with a 20V working peak reverse voltage (VRWM), 22.2–24.5V breakdown voltage (VBR), and 32.4V maximum clamping voltage (VC) at 12.3A peak pulse current. It delivers ±30kV ESD protection per IEC61000-4-2 and is used for overvoltage protection on automotive battery contacts and power management rails.
For engineers reviewing the SMF4L20A-7 datasheet, SMF4L20A-7 pinout, SMF4L20A-7 application, or SMF4L20A-7 equivalent, key selection criteria include clamping voltage margin relative to protected IC VDD, unidirectional polarity confirmation via cathode band marking, JEDEC-qualified reliability for high-reliability industrial use, and DO-219AA package thermal performance under pulsed surge conditions.
Technical Context
This TVS diode operates in avalanche breakdown mode to clamp transient surges within nanoseconds-unidirectional response time is typically <1.0ns from 0V to VBR(min). Its junction-to-ambient thermal resistance is 96°C/W on standard FR-4 PCB, enabling sustained 1.0W DC dissipation.
The device is rated for 400W peak pulse power (10/1000µs waveform), supports 40A non-repetitive forward surge current (8.3ms half-sine), and exhibits only 0.5µA reverse leakage at VRWM-critical for low-power always-on circuits like automotive body control modules.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 20V - Maximum continuous reverse operating voltage before clamping begins; sets upper limit for protected line voltage. |
| VBR (min/max) | 22.2V / 24.5V @ 1mA - Confirmed avalanche onset range; ensures reliable triggering above normal operating voltage. |
| VC @ IPP | 32.4V @ 12.3A - Clamped voltage during 10/1000µs surge; defines worst-case stress on downstream ICs. |
| PPK | 400W - Peak pulse power handling capacity; determines survivability against ISO 7637-2 Pulse 1/2/5a transients. |
| ESD Rating | ±30kV air / ±30kV contact (IEC61000-4-2) - Full-system ESD immunity without external spark gaps or RC filters. |
| Leakage Current | 0.5µA @ VRWM - Negligible standby power loss; suitable for battery-backed systems and low-IQ applications. |
| Package | DO-219AA - 2.8mm × 1.9mm surface-mount outline with 0.6mm lead length; optimized for automated placement and thermal relief. |
Pinout & Package
DO-219AA package: ultra-compact molded plastic case (UL 94V-0), matte tin-plated copper alloy leads, cathode band denotes unidirectional polarity. Weight: 0.016g. Moisture sensitivity level: MSL1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side connection to protected circuit ground | Current path during reverse-biased clamping; must be routed with minimal inductance to avoid voltage overshoot. |
| Cathode | High-side connection to protected line (e.g., battery rail) | Marked by visible band; carries full surge current into ground during transient events. |
Key Features
| Feature | Design Value |
|---|---|
| 400W peak pulse power (10/1000µs) | Withstands automotive load-dump and ISO 7637-2 Pulse 5a surges without degradation. |
| 0.5µA max reverse leakage @ VRWM | Enables direct integration on always-on 20V supply rails without measurable battery drain. |
| <1.0ns response time (unidirectional) | Clamps transients before sensitive logic or analog circuitry experiences overvoltage stress. |
| RoHS-compliant, halogen-free "Green" construction | Meets automotive OEM environmental requirements (e.g., Ford WSS-M99P9999-A1, GM GP-10B). |
| JEDEC-qualified high-reliability grade | Validated for extended temperature operation (-55°C to +175°C) in engine bay and powertrain modules. |
Applications
| Automotive Battery Protection | Industrial Power Supply Input |
|---|---|
|
Use Scenario: Protecting 12V/24V battery-fed ECUs from load dump and jump-start transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and system input capacitor. Use Value: Limits clamped voltage to 32.4V, ensuring downstream DC-DC converters (e.g., TPS543B20) remain within absolute maximum ratings. |
Use Scenario: Safeguarding AC-DC adapter outputs against induced surges in factory automation PLCs. IC Role / Device Role / Timing Role: Secondary-side transient suppression on regulated 20V auxiliary supply lines. Use Value: 0.5µA leakage preserves efficiency in energy-sensitive 24/7 control systems with tight thermal budgets. |
| USB-C Power Delivery Line | Smart Meter Battery Backup Circuit |
|
Use Scenario: Overvoltage protection on USB-C VBUS lines exposed to hot-plug and cable ESD events. IC Role / Device Role / Timing Role: Primary ESD clamp on 20V PD negotiation path prior to buck controller. Use Value: ±30kV contact ESD rating eliminates need for additional polymer TVS or multi-stage filtering. |
Use Scenario: Guarding lithium-thionyl chloride backup cells in AMI smart meters against field-induced surges. IC Role / Device Role / Timing Role: Low-leakage TVS across cell terminals to prevent false discharge triggers. Use Value: Sub-microamp leakage extends 10+ year battery life while maintaining 32.4V clamping safety margin. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ20A | DO-214AC package; 38.9V VC @ 10.3A; 400W rating; higher RθJA (110°C/W) | Larger footprint (4.5mm × 2.7mm); less suitable for dense automotive PCBs | Prefer when legacy layout compatibility outweighs space constraints |
| SMF4L20CA | Bidirectional variant; same DO-219AA package; identical VBR/VC specs but symmetric clamping | Required where bidirectional signal lines (e.g., CAN FD, LIN) need symmetrical surge suppression | Select only if polarity-agnostic protection is mandated by interface standard |
Compared with SMAJ20A, SMF4L20A-7 saves >50% board area and improves thermal coupling; versus SMF4L20CA, it provides lower leakage and avoids unnecessary bidirectional conduction in DC power rails.
Availability
SMF4L20A-7 is available at Aetrix Electronics and suitable for automotive battery protection, industrial power supply input, USB-C power delivery line, and smart meter battery backup circuit applications requiring stable component supply across extended product lifecycles.
Supply support for SMF4L20A-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 semiconductor company specializing in discrete, analog, and mixed-signal solutions, with manufacturing certified to IATF 16949 and quality systems aligned with AEC-Q200.
The SMF4L series belongs to Diodes' high-reliability TVS portfolio, engineered specifically for automotive and industrial environments demanding robust transient immunity, low leakage, and compact surface-mount form factors.
FAQ
What is the polarity configuration of SMF4L20A-7?
SMF4L20A-7 is a unidirectional TVS diode, indicated by a visible cathode band on the DO-219AA package. It conducts only during reverse-biased overvoltage events and blocks forward current up to 3V at 16A, making it suitable for DC power rail protection where polarity is fixed.
Does SMF4L20A-7 meet AEC-Q200 requirements?
SMF4L20A-7 is qualified to JEDEC standards referenced in AEC-Q200 for high-reliability operation and is manufactured in IATF 16949-certified facilities. While not marked with a Q-suffix, its qualification path aligns with AEC-Q200 stress test profiles for passive components including temperature cycling and surge endurance.
How does the DO-219AA package affect thermal performance?
The DO-219AA package achieves 96°C/W junction-to-ambient thermal resistance on standard FR-4 with 2 oz. copper pads. Its low profile (0.6mm lead length) and direct cathode tab soldering enable efficient heat transfer to the PCB, supporting 1.0W DC power dissipation and stable 400W pulse handling without derating below +125°C ambient.
Can SMF4L20A-7 replace SMAJ20A in existing designs?
Yes, with layout revision: SMF4L20A-7 uses DO-219AA (2.8mm × 1.9mm) versus SMAJ20A's DO-214AC (4.5mm × 2.7mm). Electrical specs are closely matched (VBR 22.2–24.5V vs. 22.2–24.5V; VC 32.4V vs. 38.9V), but the lower clamping voltage and smaller footprint require updated pad geometry and may improve surge margin in space-constrained applications.
SMF4L20A-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):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 32.4V
- Current - Peak Pulse (10/1000µs):
- 12.3A
- 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
SMF4L20A-7 FAQ
1.How can I place an order for SMF4L20A-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L20A-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 SMF4L20A-7 reliable?
The price and inventory of SMF4L20A-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L20A-7 is usually 5 days.
3.What payment methods are accepted for SMF4L20A-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L20A-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L20A-7?
SMF4L20A-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L20A-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 SMF4L20A-7?
For technical support, including SMF4L20A-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L20A-7 requirements.
6.How does Aetrix verify that SMF4L20A-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L20A-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 SMF4L20A-7 meets industry standards.
7.What is the process for return or replacement of SMF4L20A-7?
All SMF4L20A-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L20A-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 SMF4L20A-7 part is unused and in its original packaging.
Return procedure for SMF4L20A-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L20A-7 Tags
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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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Diodes Incorporated
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