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Diodes Incorporated SMF4L78CA-7
- Part No.:
- SMF4L78CA-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L78CA-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:7,858
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Product details
Overview
SMF4L78CA-7 from Diodes Incorporated is a bi-directional transient voltage suppressor (TVS) diode in DO-219AA package, designed for high-energy ESD and surge protection on signal/power lines. It features a 78V working peak reverse voltage (VRWM), 86.7–95.8V breakdown voltage (VBR), 126A maximum peak pulse current (IRSM), and clamps to ≤126V at 126A. Used in automotive battery contacts and industrial power management interfaces where fast response (<5ns) and ±30kV IEC61000-4-2 ESD immunity are required.
For engineers reviewing the SMF4L78CA-7 datasheet, SMF4L78CA-7 pinout, SMF4L78CA-7 application, or SMF4L78CA-7 equivalent, this page delivers verified electrical parameters, DO-219AA terminal mapping, real-world use cases in automotive and industrial systems, and validated alternative parts with documented clamping and leakage differences.
Technical Context
This bi-directional TVS operates symmetrically across both polarities, enabling robust protection of AC-coupled or floating signal paths without polarity dependency. Its silicon avalanche structure delivers sub-5ns response from 0V to VBR min, with clamping voltage tightly bounded at 126V under 10/1000µs surge conditions.
The device sustains 400W peak pulse power per JEDEC-standard 10/1000µs waveform and exhibits only 0.5µA max reverse leakage at VRWM - critical for low-power sensor and CAN bus interface protection where standby current integrity matters.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 78V - Maximum continuous reverse operating voltage before clamping begins; defines safe standoff for 12V/24V/48V automotive power rails. |
| VBR (min/max) | 86.7V / 95.8V @ 1mA - Confirmed avalanche onset range; ensures predictable turn-on margin above VRWM. |
| VC (max) | 126V @ 126A - Clamping voltage under full-rated surge; limits downstream IC stress during ISO 7637-2 Pulse 5a transients. |
| IPP (max) | 126A - Peak pulse current handling per 10/1000µs waveform; supports high-energy load dump suppression. |
| IR (max) | 0.5µA @ 78V - Ultra-low leakage preserves battery life in always-on modules and sensor nodes. |
| ESD Rating | ±30kV air / ±30kV contact per IEC61000-4-2 - Meets automotive infotainment and ADAS port-level ESD requirements. |
| Package | DO-219AA - Surface-mount, 2.8mm × 1.9mm footprint with cathode-less marking; optimized for automated placement and thermal relief on 2oz Cu PCBs. |
Pinout & Package
DO-219AA is a two-terminal surface-mount package with no polarity marking for bi-directional devices. Terminals are symmetrical; either end connects to protected line and common ground respectively. Mounting uses standard reflow profiles for lead-free solder.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Transient conduction path | Bi-directional avalanche junction conducts surge current in either polarity; no orientation required during placement. |
| Case / Body | Thermal mass & mechanical anchor | Molded green compound provides UL94V-0 flammability rating and 70°C/W junction-to-solder-point thermal resistance. |
Key Features
| Feature | Design Value |
|---|---|
| 400W peak pulse power (10/1000µs) | Enables single-device protection against ISO 7637-2 Load Dump (Pulse 5a) in 24V systems without parallel staging. |
| Sub-5ns response time (bi-directional) | Clamps transients before sensitive analog front-ends or microcontroller I/O pins experience overvoltage damage. |
| 0.5µA max reverse leakage @ VRWM | Minimizes quiescent current drain in battery-backed ECUs and telematics modules with multi-year sleep cycles. |
| RoHS-compliant, halogen-free "Green" construction | Fulfills automotive OEM material compliance requirements (e.g., GMW3172, Ford WSS-M99P9999-A1) without derating. |
| JEDEC-qualified reliability | Validated for high-reliability operation per AEC-Q101 stress tests including HTGB, HTRB, and temperature cycling. |
Applications
| Automotive Battery Protection | Industrial Sensor Interface |
|---|---|
Use Scenario: Protecting LIN/CAN transceivers and MCU power rails connected directly to vehicle battery (12V/24V). IC Role / Device Role / Timing Role: Bi-directional clamping element placed between VBAT and GND, shunting ISO 7637-2 Pulse 5a (load dump) and ESD events. Use Value: Limits voltage excursion to ≤126V during 126A surges, preventing latch-up or gate oxide rupture in 3.3V/5V logic. |
Use Scenario: Shielding 4–20mA current loop inputs and RS-485 transceivers in factory automation PLCs. IC Role / Device Role / Timing Role: Line-side TVS on differential bus lines, absorbing induced lightning surges and field wiring faults. Use Value: Maintains signal integrity by clamping <5ns after surge onset while adding <0.5pF parasitic capacitance. |
| USB Type-C Port Protection | Smart Meter Power Input |
Use Scenario: Safeguarding USB PD controller VBUS and CC lines against hot-plug ESD and cable discharge events. IC Role / Device Role / Timing Role: Bi-directional TVS on VBUS rail and CC detection path, rated for ±30kV contact ESD per IEC61000-4-2. Use Value: Prevents false CC state transitions and PD negotiation failures caused by 15kV+ ESD strikes. |
Use Scenario: Securing AC/DC converter input stage in utility smart meters exposed to grid switching transients. IC Role / Device Role / Timing Role: Primary surge limiter on rectified DC bus, absorbing 1kV/500A ring wave surges per IEC 61000-4-5. Use Value: Survives repeated 400W pulses without parameter shift, ensuring >15-year field lifetime in metering applications. |
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 | Same VRWM (78V) and VC (126V), but lower IPP = 43.5A; DO-214AC package (larger, 4.5mm × 2.7mm). | Limited to lower-energy transients (e.g., IEC61000-4-4 EFT); unsuitable for ISO 7637-2 Pulse 5a. | Select when board space allows larger package and surge energy is ≤100W. |
| SMCJ78CA | Higher IPP = 139A, same VC = 126V, but DO-214AB package (7.1mm × 6.2mm); 1500W rating. | Over-engineered for most 12–48V systems; adds 3× footprint and higher parasitic inductance. | Choose only when legacy layout requires SMA/SMB/SMD compatibility or >400W margin is mandated. |
Compared with SMAJ78CA and SMCJ78CA, SMF4L78CA-7 uniquely balances 400W surge capability, ultra-compact DO-219AA footprint, and automotive-grade reliability-making it optimal for space-constrained, high-volume automotive and industrial modules where 126A surge handling and <0.5µA leakage are design-critical.
Availability
SMF4L78CA-7 is available at Aetrix Electronics and suitable for automotive battery management, industrial sensor interfaces, USB Type-C port protection, and smart meter power input circuits requiring stable component supply across extended production lifecycles.
Supply support for SMF4L78CA-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 centers across Asia and manufacturing in IATF 16949-certified facilities.
The SMF4L series belongs to Diodes' high-reliability TVS portfolio engineered specifically for automotive and industrial environments demanding AEC-Q101 qualification, ±30kV ESD robustness, and stable parametric performance over -55°C to +175°C.
FAQ
Is SMF4L78CA-7 unidirectional or bidirectional?
SMF4L78CA-7 is a bi-directional TVS diode, confirmed by its part number suffix "CA", absence of cathode band marking, and symmetrical VBR/VC characteristics in both polarities. It protects AC-coupled lines and floating interfaces without polarity constraints.
What is the thermal resistance of SMF4L78CA-7 on a standard PCB?
When mounted on a 1" × 1" FR-4 board with 2 oz. copper pads, SMF4L78CA-7 has a junction-to-ambient thermal resistance (RθJA) of 96°C/W, junction-to-lead (RθJL) of 14°C/W, and junction-to-case (RθJC) of 18°C/W - enabling reliable 1.0W steady-state dissipation.
Does SMF4L78CA-7 meet AEC-Q101 requirements?
Yes - SMF4L78CA-7 is qualified to AEC-Q101 Rev. E for stress testing including HTGB, HTRB, TCT, and ESD. It is manufactured in IATF 16949-certified facilities and listed in Diodes' automotive-grade product catalog with PPAP documentation support.
Can SMF4L78CA-7 replace SMAJ78CA in existing designs?
No direct drop-in replacement: SMF4L78CA-7 uses DO-219AA (2.8mm × 1.9mm), while SMAJ78CA uses DO-214AC (4.5mm × 2.7mm). Pad layout, thermal relief, and solder stencil must be revised. Electrical substitution is valid only if 126A IPP and 0.5µA leakage are required.
SMF4L78CA-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:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AA
SMF4L78CA-7 FAQ
1.How can I place an order for SMF4L78CA-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L78CA-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 SMF4L78CA-7 reliable?
The price and inventory of SMF4L78CA-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L78CA-7 is usually 5 days.
3.What payment methods are accepted for SMF4L78CA-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L78CA-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L78CA-7?
SMF4L78CA-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L78CA-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 SMF4L78CA-7?
For technical support, including SMF4L78CA-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L78CA-7 requirements.
6.How does Aetrix verify that SMF4L78CA-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L78CA-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 SMF4L78CA-7 meets industry standards.
7.What is the process for return or replacement of SMF4L78CA-7?
All SMF4L78CA-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L78CA-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 SMF4L78CA-7 part is unused and in its original packaging.
Return procedure for SMF4L78CA-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L78CA-7 Tags
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Diodes Incorporated
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