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Diodes Incorporated SMF4L78CAQ-7
- Part No.:
- SMF4L78CAQ-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L78CAQ-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:6,469
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Product details
Overview
SMF4L78CAQ-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), 78V working peak reverse voltage (VRWM), 86.7–95.8V breakdown voltage (VBR), and 126V maximum clamping voltage (VC) at 3.2A surge current. It delivers ±30kV ESD protection (IEC61000-4-2) and is AEC-Q101 qualified for automotive battery line and power rail protection.
For engineers reviewing the SMF4L78CAQ-7 datasheet, SMF4L78CAQ-7 pinout, SMF4L78CAQ-7 application, or SMF4L78CAQ-7 equivalent, key selection criteria include clamping voltage margin vs. system rail tolerance, bi-directional surge handling for AC-coupled or floating lines, AEC-Q101 compliance for automotive deployment, and DO-219AA footprint compatibility with space-constrained PCB layouts.
Technical Context
This bi-directional TVS operates symmetrically across both polarities, enabling robust protection of differential signal lines or ungrounded DC rails without polarity dependency. Its sub-5ns response time ensures clamping activation before downstream IC damage thresholds are exceeded during fast transients like ISO 7637-2 pulse 1/2a/5a.
Designed for IATF 16949-certified production, it supports automotive-grade reliability with -55°C to +175°C operating range, 1.0W steady-state dissipation on FR-4, and halogen/antimony-free "Green" construction compliant with RoHS 3 and AEC-Q101 stress test requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400W (10/1000µs waveform); sustains high-energy surges without thermal runaway |
| Working Peak Reverse Voltage (VRWM) | 78V; maximum continuous DC or RMS voltage before significant leakage |
| Breakdown Voltage (VBR) | 86.7–95.8V @ 1mA; defines onset of avalanche conduction under transient stress |
| Maximum Clamping Voltage (VC) | 126V @ 3.2A; upper voltage limit seen by protected circuit during specified surge |
| ESD Withstand | ±30kV contact & air (IEC61000-4-2); eliminates need for external ESD staging |
| Operating Temperature | -55°C to +175°C; validated for under-hood and powertrain environments |
| AEC-Q101 Qualified | Yes; passed stress tests including HTGB, HTRB, TCT, and ESD per AEC standard |
Pinout & Package
Package: DO-219AA - surface-mount, flat lead, cathode-bandless bi-directional configuration; 1.90mm width × 2.80mm length × 0.60mm height; 0.016g weight; moisture sensitivity level 1.
| 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 |
| Case / Body | Thermal path & mechanical anchor | Molded plastic body with low RθJA (96°C/W) enables direct PCB heat sinking via copper pads |
Key Features
| Feature | Design Value |
|---|---|
| Bi-directional clamping architecture | Enables single-device protection of floating or AC-coupled nodes without polarity concerns |
| Sub-5ns response time | Activates before 10ns transients propagate into sensitive analog or communication ICs |
| AEC-Q101 qualification & PPAP capability | Meets automotive change control, traceability, and process validation requirements |
| Halogen- and antimony-free "Green" compound | Complies with EU Directive 2015/863/EU; <900ppm Br, <900ppm Cl, <1000ppm Sb |
| DO-219AA footprint | Reduces board area by ~40% vs. SMA while maintaining 400W rating and thermal performance |
Applications
| Battery Management Systems (BMS) | Automotive Infotainment Power Rails |
|---|---|
Use Scenario: Protection of 12V/24V battery input to BMS controller against load dump and jump-start surges. IC Role / Device Role / Timing Role: Primary clamping device placed upstream of DC-DC converters and MCU power supplies. Use Value: 126V clamping limits stress on 36V-rated input capacitors and avoids overvoltage shutdown of PMICs. | Use Scenario: Surge suppression on USB-C PD and HDMI power delivery lines in head units. IC Role / Device Role / Timing Role: Bi-directional transient shunt for bidirectional power/data lines subject to hot-plug and ESD events. Use Value: Symmetric clamping prevents reverse-bias damage during cable insertion/removal transients. |
| Engine Control Unit (ECU) Sensor Inputs | ADAS Camera Module Power Lines |
Use Scenario: Protection of analog sensor inputs (e.g., MAP, O2) exposed to ignition noise and alternator ripple. IC Role / Device Role / Timing Role: Low-leakage (<0.5μA @ 78V) shunt that remains transparent during normal operation. Use Value: Prevents false triggering of ADC references while clamping >100V spikes within nanoseconds. | Use Scenario: Input rail protection for 12V-powered camera modules subjected to ISO 16750-2 pulses. IC Role / Device Role / Timing Role: First-line defense against load dump (pulse 5a) and supply reversal events. Use Value: AEC-Q101 qualification and 175°C junction rating ensure reliability in sealed, thermally isolated housings. |
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 |
|---|---|---|---|
| SMAJ78CA | DO-214AC package; 400W rating; higher RθJA (110°C/W); VRWM = 78V, VC = 127V @ 3.2A | Larger footprint; less suitable for ultra-dense automotive modules | Select when legacy SMA layout reuse is required and thermal margin exceeds 15°C |
| TPSMD78CA | DO-214AB package; 600W rating; VRWM = 78V, VC = 125V @ 4.8A; higher IFSM (100A) | Higher surge capacity but larger size and non-AEC-Q101 qualified | Select for industrial power supplies where AEC-Q101 is not mandated and surge energy exceeds 400W |
Compared with SMAJ78CA and TPSMD78CA, SMF4L78CAQ-7 offers the smallest footprint (DO-219AA), lowest thermal resistance (96°C/W), and full AEC-Q101 qualification-making it optimal for next-generation automotive ECUs where space, thermal performance, and automotive compliance are jointly constrained.
Availability
SMF4L78CAQ-7 is available at Aetrix Electronics and suitable for automotive battery management, infotainment power conditioning, and ADAS camera module designs requiring stable component supply, AEC-Q101 traceability, and high-reliability transient suppression.
Supply support for SMF4L78CAQ-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 protection, power management, and signal integrity solutions for automotive, industrial, and computing markets.
The SMF4L series belongs to Diodes' AEC-Q101-qualified TVS portfolio, engineered specifically for compact, high-power-density automotive transient suppression where DO-219AA's thermal and space advantages outweigh legacy package trade-offs.
FAQ
What does the 'C' in SMF4L78CAQ-7 signify?
The 'C' denotes bi-directional configuration, confirming symmetrical clamping behavior across both polarities-critical for protecting floating or AC-coupled lines such as CAN bus stubs, USB power, or sensor bridges where polarity reversal may occur during transients.
Is SMF4L78CAQ-7 compatible with reflow soldering per J-STD-020?
Yes-it is rated for moisture sensitivity level 1 and qualified for standard Pb-free reflow profiles (peak 260°C), with matte tin finish on copper alloy leadframe ensuring reliable wetting and intermetallic formation without voiding or tombstoning on DO-219AA pads.
How does its 126V clamping voltage impact system design margin?
At 3.2A surge, VC = 126V provides ≥48V headroom above the 78V VRWM, allowing safe operation with 100V-rated downstream capacitors and 130V-maximum input PMICs-enabling direct integration without additional series impedance or voltage derating.
Can SMF4L78CAQ-7 replace older SMAJ78CA in existing designs?
Yes, with layout adaptation: DO-219AA has 1.90mm × 2.80mm footprint vs. SMAJ's 4.5mm × 2.7mm, requiring pad revision. Electrical specs match closely (VC differs by 1V), and AEC-Q101 qualification adds automotive program eligibility not present in SMAJ78CA.
SMF4L78CAQ-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):
- 78V
- Voltage - Breakdown (Min):
- 86.7V
- Voltage - Clamping (Max) @ Ipp:
- 126V
- Current - Peak Pulse (10/1000µs):
- 3.2A
- 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
SMF4L78CAQ-7 FAQ
1.How can I place an order for SMF4L78CAQ-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L78CAQ-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 SMF4L78CAQ-7 reliable?
The price and inventory of SMF4L78CAQ-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L78CAQ-7 is usually 5 days.
3.What payment methods are accepted for SMF4L78CAQ-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L78CAQ-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L78CAQ-7?
SMF4L78CAQ-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L78CAQ-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 SMF4L78CAQ-7?
For technical support, including SMF4L78CAQ-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L78CAQ-7 requirements.
6.How does Aetrix verify that SMF4L78CAQ-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L78CAQ-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 SMF4L78CAQ-7 meets industry standards.
7.What is the process for return or replacement of SMF4L78CAQ-7?
All SMF4L78CAQ-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L78CAQ-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 SMF4L78CAQ-7 part is unused and in its original packaging.
Return procedure for SMF4L78CAQ-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L78CAQ-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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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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