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Diodes Incorporated SMF4L28CAQ-7
- Part No.:
- SMF4L28CAQ-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L28CAQ-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:5,883
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Product details
Overview
SMF4L28CAQ-7 from Diodes Incorporated is a bi-directional transient voltage suppressor (TVS) diode in DO-219AA package, designed for automotive-grade ESD and surge protection. It features a 28 V working peak reverse voltage (VRWM), 31.1–34.4 V breakdown voltage (VBR), 45.4 V maximum clamping voltage (VC) at 8.8 A peak pulse current, and 400 W peak pulse power dissipation (10/1000 µs waveform). It is AEC-Q101 qualified and used in battery contact and power management circuits.
For engineers reviewing the SMF4L28CAQ-7 datasheet, SMF4L28CAQ-7 pinout, SMF4L28CAQ-7 application, or SMF4L28CAQ-7 equivalent, key selection criteria include clamping voltage margin vs. protected IC VDD tolerance, bi-directional symmetry for AC-coupled lines, IEC 61000-4-2 ±30 kV ESD rating, 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 constraints. Its sub-5 ns response time ensures suppression before downstream ICs experience overvoltage stress, and its low leakage (<0.5 µA at VRWM) minimizes standby power impact in always-on automotive modules.
The device uses planar junction technology in a molded green plastic DO-219AA package with matte tin terminals, achieving RθJC = 18 °C/W and RθJS = 70 °C/W. It sustains 40 A non-repetitive forward surge current (8.3 ms half-sine) and maintains stable clamping performance across -55°C to +175°C operating range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 28 V - Maximum continuous reverse voltage before significant leakage; sets upper limit for protected line's steady-state voltage. |
| VBR (min/max) | 31.1 V / 34.4 V - Breakdown occurs within this band at 1 mA test current; defines onset of clamping action. |
| VC @ IRSM | 45.4 V - Clamps transients to ≤45.4 V at 8.8 A peak surge; must be below protected IC's absolute maximum rating. |
| PPK | 400 W - Peak pulse power handling per 10/1000 µs waveform; determines survivability against ISO 7637-2 Pulse 1/2/5a surges. |
| IR @ VRWM | <0.5 µA - Reverse leakage at rated standoff voltage; ensures negligible quiescent current in battery-powered systems. |
| ESD Rating | ±30 kV (air/contact) per IEC 61000-4-2 - Validates immunity to human-body-model discharges in assembly and field environments. |
| Operating Temp | -55°C to +175°C - Supports under-hood automotive placement and industrial high-temp PCB layouts. |
Pinout & Package
Package: DO-219AA - Surface-mount, flat lead, bi-directional symmetrical device with no cathode band marking; dimensions: 1.90 mm × 2.80 mm × 0.60 mm (L × W × H), weight ≈ 0.016 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode (symmetrical) | Bi-directional transient conduction path | Either terminal serves as anode or cathode depending on transient polarity; no polarity-sensitive routing required. |
| Case / Mold Compound | Thermal and mechanical interface | UL 94V-0 rated green molding compound; provides insulation and enables direct PCB heat sinking via soldered terminals. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive applications including engine control units, body electronics, and ADAS sensors. |
| IATF 16949 manufacturing | Ensures consistent lot-to-lot reliability, PPAP documentation support, and change control traceability. |
| Halogen- and antimony-free | Meets RoHS 3 (2015/863/EU); Br+Cl <1500 ppm, Sb <1000 ppm - supports eco-compliance in global OEM supply chains. |
| Fast response time | <5.0 ns (bi-directional) - Limits voltage overshoot during ESD events before protected circuitry latches or fails. |
| Low thermal resistance | RθJS = 70 °C/W - Enables effective heat transfer from die to PCB copper, critical for sustained surge duty cycles. |
Applications
| Automotive Battery Interface | USB 2.0 Data Lines |
|---|---|
Use Scenario: Protection of 12 V battery feed to infotainment head unit power rail against load dump and jump-start transients. IC Role / Device Role / Timing Role: Bi-directional clamping element placed upstream of DC-DC converter input, absorbing energy before it reaches sensitive regulators. Use Value: Withstands 400 W pulses and clamps to 45.4 V, keeping downstream 42 V-rated converters within safe operating area during ISO 7637-2 Pulse 5a events. |
Use Scenario: ESD protection on differential USB D+/D− lines in telematics control units exposed to frequent connector mating cycles. IC Role / Device Role / Timing Role: Low-capacitance bi-directional TVS placed directly at USB connector, shunting fast ESD transients before they propagate into USB PHY. Use Value: ±30 kV IEC 61000-4-2 rating and <5 ns response ensure full compliance with USB-IF ESD requirements while adding <0.5 pF parasitic capacitance per line. |
| Industrial CAN Bus Nodes | Smart Meter Power Input |
Use Scenario: Transient suppression on CAN_H/CAN_L lines in factory automation nodes subjected to inductive switching noise and ground bounce. IC Role / Device Role / Timing Role: Symmetric bi-directional clamp across differential pair, maintaining common-mode integrity while suppressing common- and differential-mode surges. Use Value: Matched VBR and VC characteristics ensure balanced clamping behavior, preserving CAN signal eye diagram integrity during 400 W surge events. |
Use Scenario: Overvoltage protection on AC/DC adapter input of utility smart meters installed in outdoor meter cabinets. IC Role / Device Role / Timing Role: First-line defense against lightning-induced surges entering via mains input, placed before bridge rectifier and bulk capacitor. Use Value: 28 V VRWM allows operation with 24 V nominal input; 45.4 V VC prevents overvoltage stress on downstream 50 V-rated electrolytic capacitors during 10/1000 µs transients. |
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 |
|---|---|---|---|
| SMAJ28CA | DO-214AC package; higher RθJA (125 °C/W); same VRWM/VBR/VC specs but lower IPP (15.3 A). | Larger footprint; less suitable for dense automotive PCBs; lower surge current capacity limits use in high-energy load dump scenarios. | Select when legacy SMA footprint compatibility is required and peak surge current demand is ≤15 A. |
| TPSMD28CA | DO-214AB package; 400 W rating; slightly higher VC (47.7 V); RoHS compliant but not AEC-Q101 qualified. | Lacks automotive qualification; unsuitable for safety-critical or OEM-specified designs requiring PPAP and change control. | Select for cost-sensitive industrial applications where AEC-Q101 is not mandated and 2.3 V higher clamping is acceptable. |
Compared with SMAJ28CA and TPSMD28CA, SMF4L28CAQ-7 delivers superior thermal performance (RθJA = 96 °C/W), automotive qualification, and compact DO-219AA packaging-making it optimal for space-constrained, high-reliability automotive and industrial power interfaces.
Availability
SMF4L28CAQ-7 is available at Aetrix Electronics and suitable for automotive battery protection, USB interface hardening, industrial CAN bus nodes, and smart meter power input circuits requiring stable component supply and long-term lifecycle assurance.
Supply support for SMF4L28CAQ-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.
The SMF4L series belongs to Diodes' AEC-Q101-qualified TVS portfolio, engineered specifically for automotive and industrial transient suppression where high surge capability, low clamping, and environmental compliance are mandatory.
FAQ
What does the "C" in SMF4L28CAQ-7 signify?
The "C" denotes bi-directional configuration, meaning the device provides symmetrical clamping for both positive and negative transients. Unlike uni-directional variants (e.g., SMF4L28AQ), it has no cathode band marking and functions identically regardless of polarity applied across its terminals.
Is SMF4L28CAQ-7 compatible with reflow soldering per J-STD-020?
Yes-it is rated for Moisture Sensitivity Level 1 (MSL-1), allowing unlimited floor life and compatibility with standard Pb-free reflow profiles up to 260°C peak temperature. The matte tin finish on copper alloy leadframe ensures reliable wetting and joint integrity on FR-4 and high-Tg PCBs.
How does its clamping voltage compare to competing 28 V TVS diodes?
At 8.8 A IRSM, SMF4L28CAQ-7 clamps to 45.4 V-lower than SMAJ28CA (47.7 V) and comparable to P6SMB28CA (45.7 V). This 0.3–2.3 V margin directly improves system-level surge margin for 42 V-rated downstream components in automotive power rails.
Can SMF4L28CAQ-7 replace older SMAJ28CA in existing designs?
Yes, with layout adaptation: DO-219AA (1.9 × 2.8 mm) is smaller than DO-214AC (4.3 × 2.6 mm), requiring updated footprints and stencil apertures. Electrical replacement is direct-same VRWM, VBR, and VC-but thermal performance improves due to lower RθJA (96 vs. 125 °C/W).
SMF4L28CAQ-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):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.4V
- Current - Peak Pulse (10/1000µs):
- 8.8A
- 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
SMF4L28CAQ-7 FAQ
1.How can I place an order for SMF4L28CAQ-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L28CAQ-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 SMF4L28CAQ-7 reliable?
The price and inventory of SMF4L28CAQ-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L28CAQ-7 is usually 5 days.
3.What payment methods are accepted for SMF4L28CAQ-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L28CAQ-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L28CAQ-7?
SMF4L28CAQ-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L28CAQ-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 SMF4L28CAQ-7?
For technical support, including SMF4L28CAQ-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L28CAQ-7 requirements.
6.How does Aetrix verify that SMF4L28CAQ-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L28CAQ-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 SMF4L28CAQ-7 meets industry standards.
7.What is the process for return or replacement of SMF4L28CAQ-7?
All SMF4L28CAQ-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L28CAQ-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 SMF4L28CAQ-7 part is unused and in its original packaging.
Return procedure for SMF4L28CAQ-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L28CAQ-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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