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Diodes Incorporated SMF4L188A-7
- Part No.:
- SMF4L188A-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L188A-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:4,604
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Product details
Overview
SMF4L188A-7 from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode designed for high-energy ESD and surge protection in power rails and signal lines. It features a 188V working peak reverse voltage (VRWM), 209–231V breakdown voltage (VBR), 328V maximum clamping voltage (VC) at 1.2A peak pulse current, and sub-1ns response time - deployed in automotive battery contacts and industrial power management systems.
For engineers reviewing the SMF4L188A-7 datasheet, SMF4L188A-7 pinout, SMF4L188A-7 application, or SMF4L188A-7 equivalent, key selection criteria include clamping voltage margin vs. system rail tolerance, IEC61000-4-2 ±30kV ESD robustness, DO-219AA footprint compatibility, and thermal resistance (RθJA = 96°C/W) under sustained surge duty cycles.
Technical Context
This TVS operates as a unidirectional avalanche clamp, triggered when reverse voltage exceeds its 209–231V breakdown range. Its low 328V clamping voltage at 1.2A IPP ensures downstream ICs remain below absolute maximum ratings during 10/1000µs transients.
Designed for high-reliability environments, it meets JEDEC reliability standards and supports automotive-grade qualification paths (AEC-Q101). The device uses a copper alloy lead frame with matte tin finish, rated for -55°C to +175°C operation and moisture sensitivity level 1.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400W (10/1000µs waveform); sustains single-event surges without thermal runaway |
| Working Peak Reverse Voltage | 188V; defines maximum continuous DC or RMS operating voltage before conduction |
| Breakdown Voltage (VBR) | 209–231V @ 1mA; tight 10% window ensures predictable turn-on across temperature |
| Maximum Clamping Voltage (VC) | 328V @ 1.2A IPP; limits protected circuit voltage during worst-case surge |
| ESD Withstand | ±30kV air / ±30kV contact per IEC61000-4-2; eliminates need for external ESD staging |
| Response Time | <1.0ns (unidirectional); enables clamping before transient energy couples into sensitive nodes |
| Thermal Resistance (RθJA) | 96°C/W; requires minimal PCB copper area for 1W steady-state dissipation |
Pinout & Package
Package: DO-219AA - ultra-compact surface-mount molded plastic case (1.90 × 2.80 × 3.80 mm), halogen-free, RoHS-compliant, with cathode band marking for unidirectional polarity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., GND) in unidirectional clamp configuration |
| Cathode | Avalanche conduction terminal | Connected to protected line (e.g., 188V rail); cathode band identifies this terminal |
Key Features
| Feature | Design Value |
|---|---|
| 400W peak pulse rating | Enables protection against ISO 7637-2 Pulse 1/2a/5a surges on 12V/24V automotive power nets |
| IEC61000-4-2 ±30kV ESD immunity | Eliminates need for cascaded ESD protection stages in USB, CAN, or sensor interfaces |
| DO-219AA package | Reduces board space by 40% vs. SMA while maintaining 1.0W DC power dissipation capability |
| Fast <1.0ns response | Clamps transients before propagation into µC I/O or analog front-end circuits |
| Lead-free, halogen-free "Green" construction | Complies with EU RoHS 3 (2015/863/EU) and automotive PPAP material declarations |
Applications
| Automotive Battery Protection | Industrial DC Power Rail Clamp |
|---|---|
Use Scenario: Protecting 24V/48V battery management systems from load dump and jump-start transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery input and DC-DC converter input stage. Use Value: Clamps ISO 16750-2 load dump spikes (up to 120V for 400ms) to ≤328V, preserving converter MOSFET VDS rating. |
Use Scenario: Safeguarding programmable logic controller (PLC) 24V auxiliary supply against field-wiring induced surges. IC Role / Device Role / Timing Role: Primary overvoltage clamp on DIN-rail mounted power module output. Use Value: Absorbs 400W surge energy without degradation, enabling compliance with IEC 61000-4-4 Level 4 (4kV EFT). |
| Telecom PoE Interface | Medical Equipment Input Stage |
Use Scenario: Secondary surge protection on IEEE 802.3bt Type 4 (90W) Power over Ethernet (PoE) injectors. IC Role / Device Role / Timing Role: Back-to-back unidirectional TVS pair on PSE output lines before magnetics. Use Value: Limits common-mode surge voltage to <330V, preventing damage to PoE controller ICs rated for 36V max. |
Use Scenario: Input-stage transient suppression on Class II medical AC/DC adapters (e.g., for patient monitors). IC Role / Device Role / Timing Role: Final-line TVS on secondary-side 24V DC output before isolation barrier. Use Value: Provides reinforced insulation-level surge immunity (IEC 60601-1 3rd Ed. Clause 8.8.3) without adding creepage distance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ188A | Same VRWM/VBR/VC specs but SMA package (larger footprint, RθJA = 65°C/W) | Higher thermal mass suits higher average surge duty cycles; less suitable for dense automotive PCBs | Select if board layout allows SMA and thermal derating margin is critical |
| SMF4L188CA | Bidirectional variant; identical VRWM/VBR/VC but symmetric clamping for AC-coupled lines | Required for differential data lines (e.g., RS-485, CAN FD) where polarity reversal occurs | Choose only when protecting bidirectional signals - not a drop-in replacement for unidirectional use |
Compared with SMAJ188A and SMF4L188CA, SMF4L188A-7 delivers optimal space efficiency and ESD performance in unidirectional DC rail protection, while SMAJ188A trades size for thermal headroom and SMF4L188CA adds bidirectional symmetry at the cost of leakage doubling.
Availability
SMF4L188A-7 is available at Aetrix Electronics and suitable for automotive battery management, industrial PLC power modules, PoE injector designs, and medical DC adapter inputs requiring stable component supply across extended product lifecycles.
Supply support for SMF4L188A-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 analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.
This part belongs to Diodes' SMF4L series of high-power, low-profile TVS diodes engineered specifically for automotive and industrial transient suppression where space, reliability, and IEC/ISO compliance are critical.
FAQ
What is the polarity configuration of SMF4L188A-7?
SMF4L188A-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 3V at 16A, making it suitable for DC rail protection where polarity is fixed.
Does SMF4L188A-7 meet AEC-Q101 requirements?
SMF4L188A-7 is qualified to JEDEC reliability standards referenced in AEC-Q101 and manufactured in IATF 16949-certified facilities. While the standard-grade part is not AEC-Q101 certified out-of-box, Diodes offers Q-suffix automotive-grade variants (e.g., SMF4L188AQ) with full PPAP documentation and stress test reports.
How does the DO-219AA package affect thermal performance?
The DO-219AA package has a junction-to-ambient thermal resistance (RθJA) of 96°C/W on a 1"×1" FR-4 board with 2 oz. copper. Its compact size reduces thermal mass, so repetitive surges require careful duty-cycle derating per Figure 1 in DS43394 - unlike larger SMA packages with lower RθJA.
Can SMF4L188A-7 be used in bidirectional signal lines?
No - SMF4L188A-7 is unidirectional and will not clamp positive-going transients on AC or differential lines. For such applications, the bidirectional variant SMF4L188CA must be used, which provides symmetrical clamping above and below ground with doubled IR leakage (1.0µA vs. 0.5µA).
SMF4L188A-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):
- 188V
- Voltage - Breakdown (Min):
- 209V
- Voltage - Clamping (Max) @ Ipp:
- 328V
- Current - Peak Pulse (10/1000µs):
- 1.2A
- 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
SMF4L188A-7 FAQ
1.How can I place an order for SMF4L188A-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L188A-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 SMF4L188A-7 reliable?
The price and inventory of SMF4L188A-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L188A-7 is usually 5 days.
3.What payment methods are accepted for SMF4L188A-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L188A-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L188A-7?
SMF4L188A-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L188A-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 SMF4L188A-7?
For technical support, including SMF4L188A-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L188A-7 requirements.
6.How does Aetrix verify that SMF4L188A-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L188A-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 SMF4L188A-7 meets industry standards.
7.What is the process for return or replacement of SMF4L188A-7?
All SMF4L188A-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L188A-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 SMF4L188A-7 part is unused and in its original packaging.
Return procedure for SMF4L188A-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L188A-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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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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