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Diodes Incorporated SMF4L18CAQ-7
- Part No.:
- SMF4L18CAQ-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L18CAQ-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:9,972
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Product details
Overview
SMF4L18CAQ-7 from Diodes Incorporated is a bi-directional transient voltage suppressor (TVS) diode in DO-219AA package, rated for 400W peak pulse power (10/1000µs), 18V working peak reverse voltage (VRWM), 29.2V maximum clamping voltage (VC) at 13.7A surge current, and AEC-Q101 qualified for automotive battery contact and power line protection.
For engineers reviewing the SMF4L18CAQ-7 datasheet, SMF4L18CAQ-7 pinout, SMF4L18CAQ-7 application, or SMF4L18CAQ-7 equivalent, key selection criteria include clamping voltage margin vs. system rail, bi-directional ESD robustness (±30kV IEC61000-4-2), thermal resistance (RθJA = 96°C/W), and IATF 16949 manufacturing compliance for automotive-grade supply chain traceability.
Technical Context
This bi-directional TVS operates symmetrically across both polarities with a breakdown voltage range of 20.0–22.1V at 1mA test current, enabling robust overvoltage suppression on AC-coupled or floating signal/power lines. Its sub-5ns response time ensures clamping before downstream IC damage thresholds are exceeded during fast transients like ISO 7637-2 pulse 1/2a/3a.
Designed for surface-mount automotive applications, it delivers 13.7A maximum peak pulse current (IRSM) at 29.2V clamping while maintaining <0.5μA reverse leakage at 18V VRWM - critical for low-quiescent-power battery-connected modules where leakage directly impacts shelf life.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400W (10/1000µs waveform); sustains high-energy surges without thermal runaway in automotive load-dump scenarios. |
| Working Peak Reverse Voltage | 18V; sets maximum continuous DC or RMS AC voltage the device blocks without conduction. |
| Clamping Voltage | 29.2V at 13.7A; defines worst-case voltage seen by protected circuit during full-rated surge event. |
| ESD Rating | ±30kV air / ±30kV contact per IEC61000-4-2; eliminates need for external ESD diodes in infotainment and body control modules. |
| Thermal Resistance | RθJA = 96°C/W; enables 1.0W steady-state dissipation on standard 1"×1" FR-4 PCB with 2 oz copper. |
| AEC-Q101 Qualified | Validated for automotive underhood and cabin environments (-55°C to +175°C TJ). |
Pinout & Package
Package: DO-219AA - ultra-compact surface-mount molded plastic case (2.80mm × 1.90mm × 0.60mm height), halogen/antimony-free, matte tin-plated copper alloy leadframe, moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry point during negative transient | Connected to line being protected; forms symmetrical clamping path with cathode during bidirectional surges. |
| Cathode | Current entry point during positive transient | Typically tied to ground or common reference; completes low-impedance path for both polarity transients. |
Key Features
| Feature | Design Value |
|---|---|
| Bi-directional clamping architecture | Enables single-device protection of AC signals, differential buses (e.g., LIN, CAN FD stubs), and ungrounded power rails without polarity concerns. |
| Sub-5ns response time | Activates before 5ns from 0V to VBR min, limiting transient energy delivered to sensitive MCU I/O or analog front-ends. |
| Green molding compound (UL 94V-0) | Meets automotive flammability requirements and supports RoHS 3 / REACH compliance in final assembly. |
| Low clamping ratio (VC/VRWM = 1.62) | Minimizes overvoltage margin required between protected IC's absolute maximum rating and VRWM, improving design headroom. |
Applications
| Automotive Body Control Module (BCM) | Infotainment System Power Input |
|---|---|
Use Scenario: Protects 12V supply input of BCM microcontroller and CAN transceivers against load dump (ISO 7637-2 pulse 5a) and jump-start transients. IC Role / Device Role: Primary clamping element placed upstream of LDO regulators and ESD-sensitive communication ICs. Use Value: Limits voltage to ≤29.2V during 13.7A surge, preventing latch-up or gate oxide rupture in 3.3V/5V logic domains. |
Use Scenario: Shields USB-C PD controller and audio codec power rails from hot-plug ESD and battery reversal events. IC Role / Device Role: First-line bi-directional transient suppressor on VBUS and auxiliary power paths. Use Value: Withstands ±30kV contact ESD without degradation, eliminating secondary protection stages and reducing BOM count. |
| Electric Power Steering (EPS) Sensor Interface | ADAS Camera Module Power Line |
Use Scenario: Guards analog sensor signal conditioning circuitry (e.g., torque sensor bridge outputs) against coupled transients from motor drive switching noise. IC Role / Device Role: Low-capacitance (<50pF typical at 1MHz) bi-directional clamp on differential analog lines. Use Value: Maintains signal integrity with <0.5μA leakage at 18V, avoiding DC offset errors in precision ratiometric measurements. |
Use Scenario: Secures 5V/12V camera module power input against ignition transients and electrostatic discharge during lens actuation. IC Role / Device Role: Compact footprint TVS mounted adjacent to connector to minimize inductance in clamping path. Use Value: DO-219AA package (2.8mm × 1.9mm) fits tight space constraints near FAKRA connectors while delivering full 400W surge capability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bi-directional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18CA | DO-214AC package; 400W rating; higher RθJA (125°C/W); 29.2V VC same, but 10% larger footprint. | Less suitable for space-constrained automotive modules requiring minimal board area. | Select when legacy DO-214AC layout exists and thermal derating margin allows. |
| TPSMD18CA | DO-214AB package; 600W rating; 32.4V VC at 12.3A; higher clamping voltage reduces protected IC margin. | Better for higher-energy surges but risks exceeding 3.3V/5V IC absolute max ratings during clamping. | Prefer only if system-level testing confirms 32.4V clamping remains within downstream IC tolerance. |
Compared with SMAJ18CA and TPSMD18CA, SMF4L18CAQ-7 provides optimal balance of ultra-compact DO-219AA footprint, low 29.2V clamping, and AEC-Q101 qualification - making it the preferred choice for next-generation automotive ECUs where board space, thermal performance, and supply-chain compliance are jointly constrained.
Availability
SMF4L18CAQ-7 is available at Aetrix Electronics and suitable for automotive body control modules, infotainment power inputs, ADAS camera modules, and electric power steering sensor interfaces requiring stable component supply with full AEC-Q101 traceability.
Supply support for SMF4L18CAQ-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 manufacturer specializing in discrete, analog, and mixed-signal solutions, with operations certified to IATF 16949 and ISO 9001 standards.
The SMF4L series belongs to Diodes' AEC-Q101-qualified TVS portfolio, engineered specifically for automotive power line and interface protection where reliability, compactness, and ESD immunity are non-negotiable.
FAQ
What is the maximum operating temperature for SMF4L18CAQ-7?
The SMF4L18CAQ-7 has an operating junction temperature range of –55°C to +175°C, validated per AEC-Q101 stress testing. Its RθJA of 96°C/W allows safe operation at up to +125°C ambient when dissipating 0.5W continuously on a standard 1"×1" FR-4 PCB with 2 oz copper.
Is SMF4L18CAQ-7 unidirectional or bidirectional?
SMF4L18CAQ-7 is a bi-directional TVS diode, indicated by the "C" in its part number and absence of cathode band marking. It clamps transients of either polarity symmetrically, making it suitable for AC-coupled lines, differential buses, and floating power rails.
How does SMF4L18CAQ-7 compare to SMF4L18AQ?
SMF4L18AQ is the unidirectional version (cathode-banded), while SMF4L18CAQ-7 is bi-directional (no band). Both share identical VRWM (18V), VBR (20–22.1V), and VC (29.2V), but the unidirectional variant conducts only during positive transients and requires correct polarity installation.
Does SMF4L18CAQ-7 require derating at elevated ambient temperatures?
Yes - its peak pulse power must be linearly derated above +25°C ambient, per Figure 1 in DS43393 Rev. 3-2. At +85°C, maximum PPK drops to ~280W (70% of 400W); at +125°C, it falls to ~160W (40%). Steady-state power must also follow Figure 3, limiting PD to ~0.4W at +125°C.
SMF4L18CAQ-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:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 29.2V
- Current - Peak Pulse (10/1000µs):
- 13.7A
- 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
SMF4L18CAQ-7 FAQ
1.How can I place an order for SMF4L18CAQ-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L18CAQ-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 SMF4L18CAQ-7 reliable?
The price and inventory of SMF4L18CAQ-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L18CAQ-7 is usually 5 days.
3.What payment methods are accepted for SMF4L18CAQ-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L18CAQ-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L18CAQ-7?
SMF4L18CAQ-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L18CAQ-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 SMF4L18CAQ-7?
For technical support, including SMF4L18CAQ-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L18CAQ-7 requirements.
6.How does Aetrix verify that SMF4L18CAQ-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L18CAQ-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 SMF4L18CAQ-7 meets industry standards.
7.What is the process for return or replacement of SMF4L18CAQ-7?
All SMF4L18CAQ-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L18CAQ-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 SMF4L18CAQ-7 part is unused and in its original packaging.
Return procedure for SMF4L18CAQ-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L18CAQ-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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Diodes Incorporated
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