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Diodes Incorporated SMF4L43CAQ-7
- Part No.:
- SMF4L43CAQ-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L43CAQ-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:2,653
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Product details
Overview
SMF4L43CAQ-7 from Diodes Incorporated is a bi-directional transient voltage suppressor (TVS) diode in DO-219AA package, designed for automotive-grade overvoltage protection. It features a 43 V working peak reverse voltage (VRWM), 47.8–52.8 V breakdown voltage (VBR), 69.4 V maximum clamping voltage (VC) at 5.7 A surge current, and 400 W peak pulse power dissipation (10/1000 µs waveform). It is AEC-Q101 qualified and used to protect CAN bus interfaces, battery management systems, and infotainment power rails.
For engineers reviewing the SMF4L43CAQ-7 datasheet, SMF4L43CAQ-7 pinout, SMF4L43CAQ-7 application, or SMF4L43CAQ-7 equivalent, key selection criteria include clamping voltage margin vs. protected IC's absolute maximum rating, IEC 61000-4-2 ±30 kV ESD capability, bi-directional symmetry for AC-coupled lines, and thermal resistance (RθJA = 96 °C/W) under 1"×1" FR-4 layout conditions.
Technical Context
This bi-directional TVS operates symmetrically across both polarities, enabling robust protection of differential or AC signal paths without polarity dependency. Its sub-5 ns response time ensures suppression before sensitive downstream circuitry sustains damage during fast transients like ISO 7637-2 pulse 1/2a or ESD events.
The device leverages avalanche breakdown physics with tightly controlled VBR tolerance (±5% typical), low leakage (<0.5 µA at VRWM), and stable clamping performance up to +175°C junction temperature-critical for under-hood automotive environments where thermal derating must be validated per Figure 1 derating curve.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 43 V - Maximum continuous reverse voltage before significant leakage; sets upper limit for safe operation on 36 V nominal battery systems. |
| VBR (min/max) | 47.8 V / 52.8 V - Breakdown occurs within this band at 1 mA test current; defines minimum overvoltage threshold for clamping activation. |
| VC @ IRSM | 69.4 V at 5.7 A - Clamped voltage during 10/1000 µs surge; must remain below protected IC's absolute max rating (e.g., <75 V for 48 V automotive MCUs). |
| PPK | 400 W - Peak pulse power handling (10/1000 µs); enables survival of high-energy transients like load dump spikes in 12/24 V architectures. |
| IEC61000-4-2 ESD | ±30 kV air / ±30 kV contact - Full compliance with automotive ESD immunity standard; eliminates need for external ESD staging in most body control modules. |
| RθJA | 96 °C/W - Junction-to-ambient thermal resistance on 1"×1", 2 oz Cu FR-4; determines steady-state power derating above +25°C ambient (see Fig. 3). |
Pinout & Package
Package: DO-219AA - Surface-mount, flat lead, green molded plastic case (UL 94V-0), 0.016 g weight, moisture sensitivity level 1. Cathode band omitted to indicate bi-directional configuration.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Bi-directional avalanche terminals | No polarity marking; either terminal serves as anode or cathode depending on transient polarity-enables placement across differential pairs or AC-coupled signals without orientation check. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive use including temperature cycling, HTRB, and ESD stress-supports PPAP submission and IATF 16949 production release. |
| Bi-directional symmetry | Matched VBR and VC in both directions (±0.5 V typical spread) ensures consistent protection on RS-485, LIN, or CAN FD data lines without polarity-sensitive routing. |
| Low clamping ratio (VC/VBR) | 1.31 typical (69.4 V / 52.8 V) - Minimizes voltage overshoot during surge, reducing risk of latch-up or gate oxide damage in protected FETs or transceivers. |
| Halogen- and antimony-free | <900 ppm Br, <900 ppm Cl, <1000 ppm Sb - Meets automotive "Green" material requirements and RoHS 3 (2015/863/EU) compliance without exemptions. |
Applications
| Automotive Body Control Module (BCM) | Infotainment Power Rail Protection |
|---|---|
Use Scenario: Protects 12 V supply inputs of BCM microcontrollers and driver ICs against load dump (ISO 7637-2 Pulse 5a) and jump-start surges. IC Role / Device Role / Timing Role: Primary clamping device placed immediately after fuse and before DC-DC input filter; responds within <5 ns to limit transient voltage before bulk capacitance charges. Use Value: Withstands 400 W pulses while maintaining VC ≤ 69.4 V-ensuring MCU VDD stays below 75 V absolute maximum rating even during worst-case 120 V/50 ms load dump events. |
Use Scenario: Shields USB-C PD and HDMI power delivery circuits in head units from hot-plug transients and ESD coupling via shared ground planes. IC Role / Device Role / Timing Role: Bi-directional clamp across VBUS and GND; suppresses ±30 kV ESD strikes and 100 V/1 µs ringing induced by cable insertion/removal. Use Value: Symmetric clamping prevents reverse-bias stress on USB PD controllers during negative transients, eliminating need for dual unidirectional devices and saving PCB area. |
| CAN FD Transceiver Interface | Battery Management System (BMS) Cell Monitoring |
Use Scenario: Installed across CAN_H and CAN_L lines to absorb ESD and fast transients induced by motor switching noise in electric power steering or HVAC actuators. IC Role / Device Role / Timing Role: Low-capacitance (typ. 100 pF @ 1 MHz) bi-directional TVS placed directly at connector entry point; clamps before transceiver input pins. Use Value: Sub-5 ns response preserves CAN FD bit timing integrity up to 5 Mbps; clamping voltage margin avoids false dominant/recessive state errors during surge events. |
Use Scenario: Protects analog front-end inputs of BMS monitor ICs (e.g., TI BQ769x0) connected to individual Li-ion cell taps exposed to assembly ESD and board-level transients. IC Role / Device Role / Timing Role: Low-leakage (<0.5 µA) clamp between cell voltage sense line and ground; maintains measurement accuracy while blocking >43 V faults. Use Value: Enables direct connection to 4.2 V cell taps without voltage divider attenuation-preserving 1 mV ADC resolution while surviving ±30 kV ESD without calibration drift. |
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 |
|---|---|---|---|
| SMAJ43CA | DO-214AC package; higher RθJA (120 °C/W); same VRWM/VBR/VC specs. | Larger footprint (4.5 × 2.7 mm vs. 2.0 × 1.9 mm); less suitable for dense automotive PCBs. | Prefer SMF4L43CAQ-7 when board space is constrained or thermal performance on small pads is critical. |
| TPSMD43CA | Same DO-219AA package; 400 W rating; but only AEC-Q200 (passive component grade), not AEC-Q101. | Not qualified for semiconductor-level automotive reliability testing (e.g., HTRB, ESD HBM/MM). | Choose SMF4L43CAQ-7 for safety-critical modules requiring full AEC-Q101 validation and PPAP support. |
Compared with SMAJ43CA and TPSMD43CA, SMF4L43CAQ-7 delivers identical electrical protection in a smaller, thermally superior package with full AEC-Q101 qualification-making it optimal for next-generation compact, high-reliability automotive ECUs where footprint, thermal margin, and process compliance are jointly constrained.
Availability
SMF4L43CAQ-7 is available at Aetrix Electronics and suitable for automotive body control modules, infotainment power rails, CAN FD transceiver interfaces, and battery management system cell monitoring requiring stable component supply and full AEC-Q101 traceability.
Supply support for SMF4L43CAQ-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, specializing in high-reliability components for automotive, industrial, and computing markets.
The SMF4L series belongs to Diodes' AEC-Q101-qualified TVS portfolio, engineered specifically for automotive power and signal line protection with emphasis on low clamping ratio, bi-directional symmetry, and green material compliance.
FAQ
Is SMF4L43CAQ-7 unidirectional or bidirectional?
SMF4L43CAQ-7 is a bi-directional TVS diode, confirmed by its part number suffix "CAQ" (C = bi-directional), absence of cathode band marking, and symmetric electrical characteristics in both polarities per DS43393 Rev. 3-2 Table on page 4. Its VBR min/max and VC values are identical regardless of voltage polarity applied.
What is the maximum operating temperature for SMF4L43CAQ-7?
The maximum junction temperature is +175°C, and the operating temperature range is –55°C to +175°C, as specified in the "Maximum Ratings" table on page 2 of DS43393. This rating is validated under AEC-Q101 stress tests and supports under-hood deployment in engine control units and transmission control modules.
Does SMF4L43CAQ-7 meet automotive ESD standards?
Yes-SMF4L43CAQ-7 provides IEC 61000-4-2 ESD protection rated at ±30 kV air discharge and ±30 kV contact discharge, explicitly stated in the "Features" section on page 1 of DS43393. This exceeds the ±25 kV requirement for most automotive subsystems per ISO 10605.
How does the DO-219AA package improve thermal performance over DO-214AC?
The DO-219AA package achieves RθJA = 96 °C/W versus ~120 °C/W for DO-214AC due to its shorter thermal path from die to solder joint (RθJS = 70 °C/W), lower profile, and optimized copper leadframe geometry. This allows 18% higher steady-state power dissipation on identical PCB layouts per Figure 3 derating curve.
SMF4L43CAQ-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):
- 43V
- Voltage - Breakdown (Min):
- 47.8V
- Voltage - Clamping (Max) @ Ipp:
- 69.4V
- Current - Peak Pulse (10/1000µs):
- 5.7A
- 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
SMF4L43CAQ-7 FAQ
1.How can I place an order for SMF4L43CAQ-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L43CAQ-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 SMF4L43CAQ-7 reliable?
The price and inventory of SMF4L43CAQ-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L43CAQ-7 is usually 5 days.
3.What payment methods are accepted for SMF4L43CAQ-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L43CAQ-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L43CAQ-7?
SMF4L43CAQ-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L43CAQ-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 SMF4L43CAQ-7?
For technical support, including SMF4L43CAQ-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L43CAQ-7 requirements.
6.How does Aetrix verify that SMF4L43CAQ-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L43CAQ-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 SMF4L43CAQ-7 meets industry standards.
7.What is the process for return or replacement of SMF4L43CAQ-7?
All SMF4L43CAQ-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L43CAQ-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 SMF4L43CAQ-7 part is unused and in its original packaging.
Return procedure for SMF4L43CAQ-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L43CAQ-7 Tags
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