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Diodes Incorporated SMF4L40CA-7
- Part No.:
- SMF4L40CA-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L40CA-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:5,193
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Product details
Overview
SMF4L40CA-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 40V working peak reverse voltage (VRWM), 44.4–49.1V breakdown voltage (VBR), 64.5V maximum clamping voltage (VC) at 6.2A peak pulse current, and 400W peak pulse power dissipation (10/1000µs waveform). It is used in automotive battery contacts and industrial I/O interfaces requiring robust ±30kV IEC61000-4-2 ESD immunity.
For engineers reviewing the SMF4L40CA-7 datasheet, SMF4L40CA-7 pinout, SMF4L40CA-7 application, or SMF4L40CA-7 equivalent, key selection criteria include clamping voltage margin vs. protected IC VCC, bidirectional symmetry for AC-coupled lines, DO-219AA thermal performance under PCB trace constraints, and AEC-Q200 readiness for automotive deployment.
Technical Context
This bi-directional TVS operates symmetrically across both polarities, with identical breakdown and clamping behavior in forward and reverse directions-critical for protecting differential buses (e.g., CAN, RS-485) and ungrounded sensor inputs. Its sub-5ns response time ensures suppression before downstream ICs experience overstress.
The device leverages silicon avalanche structure optimized for low dynamic impedance and tight VBR tolerance (±5% typical), enabling predictable clamping under fast-rising transients. Its 1.0W DC power rating and 96°C/W junction-to-ambient thermal resistance require minimal copper area for sustained surge handling in compact layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Device Type | Bi-directional TVS diode - provides symmetrical overvoltage clamping on AC or floating lines without polarity dependency. |
| VRWM | 40V - maximum continuous reverse voltage before significant leakage; sets upper limit for safe operation in 36V automotive systems. |
| VBR (min/max) | 44.4V / 49.1V @ 1mA - defines guaranteed conduction onset window; ensures reliable triggering above system operating voltage. |
| VC @ IPP = 6.2A | 64.5V max - clamping voltage during 10/1000µs surge; determines maximum stress imposed on protected circuitry. |
| PPK | 400W - peak pulse power handling per JEDEC standard; supports repeated 6.2A surges without degradation. |
| ESD Rating | ±30kV contact & air per IEC61000-4-2 - qualifies for direct user-interface port protection without external shielding. |
| Operating Temp | −55°C to +175°C - enables placement near hot components (e.g., power converters, engine control units) without derating. |
Pinout & Package
Package: DO-219AA - ultra-compact surface-mount outline (2.80mm × 1.90mm × 0.60mm height), molded green compound (UL 94V-0), matte tin terminals on copper alloy lead frame. Moisture sensitivity level 1 (J-STD-020).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode | Bi-directional terminals | No cathode band marking - confirms symmetrical construction; either terminal serves as anode or cathode depending on transient polarity. |
Key Features
| Feature | Design Value |
|---|---|
| 400W Peak Pulse Power | Enables single-device protection against ISO 7637-2 Pulse 1/2a/3a surges in 12V automotive systems without parallel staging. |
| ±30kV ESD Immunity | Eliminates need for secondary ESD filters on USB, HDMI, or display interface connectors in consumer and industrial equipment. |
| DO-219AA Thermal Performance | 96°C/W RθJA allows >1W steady-state dissipation on minimal 1"×1" FR-4 pad - ideal for space-constrained modules. |
| Halogen & Antimony Free | Meets IPC-1752A "Green" requirements (<900ppm Br/Cl, <1000ppm Sb); supports RoHS 3 and automotive ELV compliance. |
Applications
| Automotive Battery Line Protection | Industrial Sensor Interface |
|---|---|
|
Use Scenario: Protecting microcontroller GPIOs and LIN transceivers connected directly to vehicle battery rail subject to load dump and jump-start transients. IC Role / Device Role: Primary clamping element placed between battery feed and protected IC power input. Use Value: Withstands 64.5V clamping at 6.2A, limiting stress on 48V-tolerant automotive MCUs while surviving repeated 400W pulses. |
Use Scenario: Shielding analog outputs of pressure/temperature sensors in factory automation PLC modules exposed to cable-induced surges. IC Role / Device Role: Bidirectional shunt clamp on 0–10V or 4–20mA output lines. Use Value: Symmetric clamping prevents signal inversion during negative-going transients; 1.2µA IR at 40V ensures negligible offset error in precision analog paths. |
| USB-C Port ESD Protection | RS-485 Transceiver I/O Protection |
|
Use Scenario: Front-line ESD guard on USB-C CC, D+/D−, and VBUS pins in portable docking stations. IC Role / Device Role: First-stage transient absorber before integrated ESD diodes in USB controller or PMIC. Use Value: ±30kV IEC61000-4-2 rating meets USB-IF compliance; DO-219AA footprint fits within 2.0mm board edge clearance limits. |
Use Scenario: Protecting half-duplex RS-485 transceivers (e.g., MAX13487) in building management systems with long field wiring. IC Role / Device Role: Line-to-ground TVS on A/B differential pair and common-mode node. Use Value: 64.5V VC ensures transceiver survival during 1kV/500Ω surge tests; bidirectional operation maintains differential integrity during polarity-reversal events. |
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 |
|---|---|---|---|
| SMAJ40CA | Same VRWM/VBR/VC specs but in larger SMA (DO-214AC) package; 100°C/W RθJA vs. 96°C/W. | Requires ~2.5× more PCB area; better suited for manual assembly or high-volume wave-solder processes. | Select when legacy layout compatibility or higher hand-solder thermal margin is prioritized over miniaturization. |
| TPSMD40CA | 400W rating, same DO-219AA package, but lower 62V VC at 6.2A and tighter 44.4–46.5V VBR range. | Better clamping margin for 3.3V/5V logic rails; slightly reduced surge energy headroom due to lower PPK derating curve. | Prefer for cost-sensitive consumer designs where 2.5V lower VC enables use with 36V-rated interface ICs. |
Compared with SMAJ40CA and TPSMD40CA, SMF4L40CA-7 delivers optimal balance of ultra-small DO-219AA footprint, industry-leading 64.5V clamping ceiling, and full AEC-Q200 qualification path-making it the preferred choice for next-gen automotive ECUs and space-constrained industrial gateways.
Availability
SMF4L40CA-7 is available at Aetrix Electronics and suitable for automotive battery line protection, industrial sensor interface design, USB-C port hardening, and RS-485 transceiver I/O protection requiring stable component supply across multi-year production cycles.
Supply support for SMF4L40CA-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 distribution operations across Asia, Europe, and North America.
The SMF4L series belongs to Diodes' high-reliability transient suppression portfolio, engineered specifically for AEC-Q200-compliant automotive subsystems and industrial environments demanding extended temperature operation and robust ESD immunity.
FAQ
What is the polarity configuration of SMF4L40CA-7?
SMF4L40CA-7 is a bi-directional TVS diode with no cathode band marking-its terminals are functionally identical and provide symmetrical clamping in both forward and reverse bias directions. This eliminates orientation concerns during placement and supports AC-coupled or floating signal lines.
Does SMF4L40CA-7 meet automotive qualification standards?
While the base SMF4L40CA-7 is not AEC-Q200 certified, Diodes offers the automotive-grade Q-suffix variant SMF4L40CAQ-7, which undergoes full AEC-Q200 stress testing, PPAP documentation, and is manufactured in IATF 16949-certified facilities-required for safety-critical vehicle subsystems.
How does the DO-219AA package affect thermal performance compared to SMA?
DO-219AA delivers 96°C/W junction-to-ambient thermal resistance-4% lower than SMA's typical 100°C/W-due to its shorter thermal path and optimized copper lead frame. This enables 5–7% higher sustained power handling on identical PCB copper area, critical for compact automotive modules.
Can SMF4L40CA-7 be used in place of unidirectional TVS diodes?
No-it is strictly bi-directional and lacks polarity marking. Substituting it for a unidirectional part (e.g., SMF4L40A) would expose protected circuits to forward conduction during normal operation, causing excessive leakage and potential latch-up. Always match device directionality to circuit topology.
SMF4L40CA-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):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 6.2A
- 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
SMF4L40CA-7 FAQ
1.How can I place an order for SMF4L40CA-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L40CA-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 SMF4L40CA-7 reliable?
The price and inventory of SMF4L40CA-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L40CA-7 is usually 5 days.
3.What payment methods are accepted for SMF4L40CA-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L40CA-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L40CA-7?
SMF4L40CA-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L40CA-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 SMF4L40CA-7?
For technical support, including SMF4L40CA-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L40CA-7 requirements.
6.How does Aetrix verify that SMF4L40CA-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L40CA-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 SMF4L40CA-7 meets industry standards.
7.What is the process for return or replacement of SMF4L40CA-7?
All SMF4L40CA-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L40CA-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 SMF4L40CA-7 part is unused and in its original packaging.
Return procedure for SMF4L40CA-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L40CA-7 Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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ESD5Z5.0T1G
onsemi
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DESD5V0U1BB-7
Diodes Incorporated
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Diodes Incorporated
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PESD2V0Y1BSFYL
Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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