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Diodes Incorporated SMF4L120A-7
- Part No.:
- SMF4L120A-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L120A-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:9,363
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Product details
Overview
SMF4L120A-7 from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode with a 120V working peak reverse voltage (VRWM), 133V minimum breakdown voltage (VBR), and 193V maximum clamping voltage (VC) at 1A surge current. It delivers fast response (<1.0ns), ±30kV ESD protection per IEC61000-4-2, and is packaged in DO-219AA for space-constrained power rail protection in automotive battery interfaces.
For engineers reviewing the SMF4L120A-7 datasheet, SMF4L120A-7 pinout, SMF4L120A-7 application, or SMF4L120A-7 equivalent, key selection criteria include clamping voltage margin relative to system rail, 10/1000µs pulse power handling, unidirectional polarity marking, JEDEC-compliant reliability, and DO-219AA thermal performance on FR-4 PCBs.
Technical Context
This TVS operates as a unidirectional avalanche clamp, triggered when reverse voltage exceeds 133V (min), limiting transient energy by shunting surge current to ground while maintaining <193V across protected circuitry. Its junction capacitance is low enough to avoid signal integrity impact in DC power lines.
The device uses silicon planar construction with a cathode band marking, optimized for high-reliability automotive and industrial environments. Thermal resistance from junction to solder point is 70°C/W, enabling stable operation up to +175°C junction temperature under defined derating conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 120V - Maximum continuous reverse operating voltage before clamping begins |
| VBR (min) | 133V - Minimum breakdown voltage at 1mA test current; defines turn-on threshold |
| VC (max) | 193V - Maximum clamped voltage at 1A peak pulse current; determines worst-case overvoltage seen by downstream ICs |
| PPK | 400W - Peak pulse power dissipation (10/1000µs waveform); quantifies transient energy absorption capability |
| ESD Rating | ±30kV contact/air - Complies with IEC61000-4-2 Level 4; eliminates need for external ESD staging in many designs |
| TJ Range | −55°C to +175°C - Enables deployment in under-hood automotive and industrial power systems without thermal derating loss |
Pinout & Package
Package: DO-219AA - Surface-mount, flat lead, molded plastic package with matte tin finish on copper alloy lead frame; 0.016g weight; UL 94V-0 rated; moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input side of unidirectional clamp | Connected to protected line (e.g., 12V battery rail); conducts only during forward-biased transients or faults |
| Cathode | Clamp output / ground reference | Connected to system ground; carries full surge current during reverse overvoltage events; marked with cathode band |
Key Features
| Feature | Design Value |
|---|---|
| 400W peak pulse power | Enables robust suppression of ISO 7637-2 Pulse 1/2a/5a surges in 12V automotive systems without derating |
| 193V max clamping at 1A | Provides ≥27% margin above 120V VRWM, ensuring safe operation even with 10% tolerance stack-up in high-voltage rails |
| Sub-1ns response time | Protects sensitive microcontrollers and PMICs before transient energy couples into IC pins |
| RoHS-compliant & halogen-free | Meets automotive OEM environmental requirements (Br+Cl <1500ppm, Sb <1000ppm) without compromising surge performance |
Applications
| Battery Management System Protection | Automotive Infotainment Power Rail |
|---|---|
Use Scenario: Protecting BMS monitoring ICs and cell-balancing circuits from load dump and jump-start transients on 12V/24V battery inputs. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery input and primary DC-DC converter input stage. Use Value: Clamps 120V-rated rail to ≤193V during 100V–150V transients, preserving 200V-rated input capacitors and preventing PMIC latch-up. | Use Scenario: Safeguarding USB-C PD controllers and display power supplies against ESD and ignition noise in head unit power distribution. IC Role / Device Role / Timing Role: Primary clamping device on 5V/12V VBUS lines upstream of LDOs and USB switch ICs. Use Value: Delivers ±30kV ESD immunity without adding series impedance, maintaining signal integrity for high-speed USB 2.0 data paths. |
| Industrial PLC Input Module | EV Charging Station Control Board |
Use Scenario: Shielding isolated analog front-ends and digital I/O supervisors from field-induced surges on 24V control bus wiring. IC Role / Device Role / Timing Role: First-line transient suppressor on DIN-rail power entry before DC-DC isolation stage. Use Value: Withstands repeated 400W pulses per IEC 61000-4-5 Combination Wave (1.2/50μs + 8/20μs), extending module MTBF in factory environments. | Use Scenario: Protecting CAN FD communication isolators and MCU reset lines from conducted noise during AC/DC conversion switching in Level 2 chargers. IC Role / Device Role / Timing Role: Localized clamping on 3.3V/5V auxiliary rails feeding communication ICs near high-power gate drivers. Use Value: Maintains <193V clamping under 1A surge, preventing false resets and CAN bus lockup during high-dV/dt events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ120A | Same VRWM (120V), but lower PPK (400W vs. SMAJ's 400W), larger SMA package (DO-214AC), higher RθJA (110°C/W) | Less suitable for ultra-thin modules due to 2.3mm height vs. DO-219AA's 1.2mm profile | Select SMAJ120A only if legacy board layout requires SMA footprint compatibility |
| SMCJ120A | Higher PPK (1500W), same VRWM, larger SMC package (DO-214AB), slower response (~1.5ns), higher VC (199V) | Over-specified for 120V rail protection where space and cost are constrained | Choose SMCJ120A only when system-level testing confirms need for >400W surge margin |
Compared with SMAJ120A and SMCJ120A, SMF4L120A-7 offers identical 120V standoff and 400W rating in a 40% smaller footprint and 37% lower thermal resistance-making it optimal for next-gen compact automotive and industrial power modules requiring high-density layout and thermal efficiency.
Availability
SMF4L120A-7 is available at Aetrix Electronics and suitable for automotive battery management, infotainment power conditioning, and industrial PLC input protection requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SMF4L120A-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' high-power TVS portfolio designed specifically for AEC-Q200-compliant transient suppression in harsh-environment 12V/24V/48V power systems, emphasizing low-profile packaging, tight parameter tolerances, and JEDEC-qualified reliability.
FAQ
What is the polarity configuration of SMF4L120A-7?
SMF4L120A-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 and blocks forward current up to its 3V VF rating at 16A. This configuration is intended for DC power line protection where polarity is fixed and reverse conduction must be prevented.
Does SMF4L120A-7 meet AEC-Q200 requirements?
SMF4L120A-7 is not AEC-Q200 qualified; however, Diodes offers the automotive-grade Q-suffix variant SMF4L120AQ-7, which is AEC-Q200 qualified, PPAP-capable, and manufactured in IATF 16949-certified facilities. The standard SMF4L120A-7 meets JEDEC high-reliability standards referenced in AEC-Q documents but lacks formal automotive qualification documentation.
How does the DO-219AA package affect thermal performance?
The DO-219AA package provides a junction-to-solder-point thermal resistance (RθJS) of 70°C/W, significantly lower than SMA (110°C/W) or SMC (100°C/W) packages. This enables higher sustained surge duty cycles on compact PCBs with minimal copper area, especially when mounted on 2 oz. copper pads per Diodes' recommended layout.
Can SMF4L120A-7 be used in bidirectional signal lines?
No-SMF4L120A-7 is unidirectional and unsuitable for bidirectional signal lines like RS-485 or CAN. For such applications, the bi-directional variant SMF4L120CA-7 must be used, which has symmetric clamping in both polarities and no cathode band marking. Using the unidirectional version on AC-coupled or bidirectional lines risks forward conduction and failure.
SMF4L120A-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):
- 120V
- Voltage - Breakdown (Min):
- 133V
- Voltage - Clamping (Max) @ Ipp:
- 193V
- Current - Peak Pulse (10/1000µs):
- 2A
- 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
SMF4L120A-7 FAQ
1.How can I place an order for SMF4L120A-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L120A-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 SMF4L120A-7 reliable?
The price and inventory of SMF4L120A-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L120A-7 is usually 5 days.
3.What payment methods are accepted for SMF4L120A-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L120A-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L120A-7?
SMF4L120A-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L120A-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 SMF4L120A-7?
For technical support, including SMF4L120A-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L120A-7 requirements.
6.How does Aetrix verify that SMF4L120A-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L120A-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 SMF4L120A-7 meets industry standards.
7.What is the process for return or replacement of SMF4L120A-7?
All SMF4L120A-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L120A-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 SMF4L120A-7 part is unused and in its original packaging.
Return procedure for SMF4L120A-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L120A-7 Tags
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ESD9B5.0ST5G
onsemi
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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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Diodes Incorporated
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