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Diodes Incorporated DFLT40A-7
- Part No.:
- DFLT40A-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- POWERDI®123
- Datasheet:
-
DFLT40A-7.pdf
- Description:
- TVS DIODE 40VWM 64.5VC PWRDI 123
- Quantity:
- Payment:
- Shipping:
Inventory:29,569
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Product details
Overview
DFLT40A-7 from Diodes Incorporated is a unidirectional transient voltage suppressor (TVS) diode in PowerDI123 package, designed for primary overvoltage protection of DC power rails and signal lines. It features a 40V reverse standoff voltage (VRWM), 44.4–49.1V breakdown voltage (VBR), 64.5V clamping voltage (VC) at 3.49A peak pulse current, and 225W peak pulse power dissipation (10/1000µs waveform).
For engineers reviewing the DFLT40A-7 datasheet, DFLT40A-7 pinout, DFLT40A-7 application, or DFLT40A-7 equivalent, this device is selected for robust ESD and surge immunity in automotive infotainment power supplies, industrial sensor interfaces, and USB-C port protection where low clamping voltage and fast response (<1ns) are critical.
Technical Context
This TVS operates in avalanche breakdown mode to clamp transient overvoltages above its standoff threshold while maintaining low leakage (<1.0µA at VRWM). Its unidirectional configuration provides asymmetric protection-blocking forward conduction beyond ~3.5V VF while offering bidirectional surge suppression only on the reverse-biased side.
The device is optimized for surface-mount reliability in high-reliability environments: it meets RoHS 3, halogen- and antimony-free "Green" requirements, has moisture sensitivity level 1, and is qualified for automotive-grade change control (AEC-Q101-ready via DFLT40AQ variant).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reverse Standoff Voltage (VRWM) | 40 V - Maximum continuous DC operating voltage before significant leakage begins. |
| Breakdown Voltage (VBR) | 44.4–49.1 V @ 1.0 mA - Voltage at which avalanche conduction initiates; defines turn-on threshold under transient stress. |
| Clamping Voltage (VC) | 64.5 V @ 3.49 A - Maximum voltage seen by protected circuit during 10/1000µs surge; determines system-level overvoltage margin. |
| Peak Pulse Power (PPK) | 225 W (10/1000µs) - Sustained surge energy handling capability without failure; derates linearly above +25°C ambient. |
| Thermal Resistance (RθJA) | 125 °C/W - Junction-to-ambient thermal impedance on FR-4 with 1-inch² 2oz copper pad; governs steady-state power derating. |
| Capacitance (CT) | ~25 pF @ 0 V - Low parasitic capacitance enables use on high-speed data lines (e.g., CAN, RS-485) without signal integrity degradation. |
Pinout & Package
Package: PowerDI123 - surface-mount, single-ended, cathode-band marked plastic package with matte tin annealed terminals; 0.01 g mass; UL 94V-0 rated molding compound.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input/Line-side connection | Connected to protected line (e.g., VBUS, CAN_H); conducts forward current during fault if polarity permits. |
| Cathode | Output/Ground-side connection | Connected to system ground or return path; carries full surge current during clamping; tab is electrically tied to cathode. |
| Cathode Band | Polarity indicator | Visible marking on package top surface identifying cathode terminal; essential for correct PCB layout orientation. |
Key Features
| Feature | Design Value |
|---|---|
| 225W peak pulse power rating | Enables protection against IEC 61000-4-5 Level 4 surges (4kV/2Ω) on 12–48V DC rails without derating or parallel devices. |
| Low clamping ratio (VC/VBR ≈ 1.35) | Minimizes overvoltage stress on downstream ICs-critical for 3.3V/5V logic supply rail protection. |
| PowerDI123 footprint | Reduces PCB area vs. SMA/SMB; supports automated placement; thermal performance exceeds SOD-123 by 3× lower RθJA. |
| RoHS 3 / Halogen-free compliance | Meets automotive and industrial environmental mandates without compromising surge robustness or solderability. |
Applications
| Automotive Infotainment Power Rail | Industrial RS-485 Interface |
|---|---|
Use Scenario: Protecting 12V supply input to head unit MCU and display driver ICs against load dump and alternator transients. IC Role / Device Role: Primary unidirectional TVS placed between fuse output and DC-DC input capacitor. Use Value: Clamps 12V rail to ≤64.5V during 100A/100ms load dump events, preventing latch-up or burnout of downstream regulators. | Use Scenario: Shielding RS-485 transceiver pins (A/B) from ESD and lightning-induced surges in factory automation nodes. IC Role / Device Role: Point-of-entry TVS on differential bus lines, mounted adjacent to connector. Use Value: 25pF capacitance avoids signal distortion at 10 Mbps; 64.5V clamping preserves transceiver common-mode range (−7V to +12V). |
| USB-C Port VBUS Protection | Smart Meter Battery Backup Circuit |
Use Scenario: Safeguarding 5–20V VBUS line in USB-C PD sink applications against hot-plug overshoot and cable ESD. IC Role / Device Role: Unidirectional TVS between VBUS and GND, upstream of buck converter. Use Value: 40V VRWM allows compatibility with USB-C PD 20V profiles; 3.49A IPP handles 8kV contact ESD per IEC 61000-4-2. | Use Scenario: Overvoltage protection of supercapacitor backup rail (36–42V) in AMI smart meters exposed to grid switching transients. IC Role / Device Role: Standoff-rated TVS across backup capacitor bank to prevent overcharge during AC mains coupling events. Use Value: 40V VRWM matches nominal 36V rail; 225W rating absorbs 100ms 500V transients without degradation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40A | Same VRWM (40V), higher VC (69.4V), lower PPK (400W but in larger SMA package), RθJA = 150°C/W | Requires more PCB area; less effective thermal management on dense boards | Choose when legacy SMA footprint is fixed and higher clamping voltage is acceptable. |
| DFLT40AQ | Identical electrical specs; AEC-Q101 qualified, PPAP-capable, manufactured in IATF 16949 facility | Mandatory for automotive production; not required for industrial prototypes | Specify DFLT40AQ for Tier-1 automotive programs; DFLT40A-7 suffices for non-automotive volume production. |
Compared with SMAJ40A, DFLT40A-7 delivers tighter clamping (−4.9V), better thermal performance (−25°C/W RθJA), and 30% smaller footprint; versus DFLT40AQ, it offers identical protection performance at lower cost and lead time for non-automotive use cases.
Availability
DFLT40A-7 is available at Aetrix Electronics and suitable for automotive infotainment power rail protection, industrial RS-485 interface hardening, and USB-C VBUS surge suppression requiring stable component supply across design-in, prototyping, and volume manufacturing phases.
Supply support for DFLT40A-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 DFLT series targets high-reliability transient suppression in automotive, industrial, and communications systems, emphasizing low clamping, compact packaging, and environmental compliance without sacrificing surge robustness.
FAQ
What is the maximum operating temperature for DFLT40A-7?
The DFLT40A-7 has an operating junction temperature range of −65°C to +150°C. Its thermal resistance (RθJA = 125°C/W) means that at 1.0W steady-state dissipation on a standard FR-4 board, junction temperature rises ~125°C above ambient-so maximum safe ambient is +25°C for full-power DC operation. Derating applies per Figure 1 in DS30581.
Is DFLT40A-7 bidirectional or unidirectional?
DFLT40A-7 is unidirectional. It functions as a reverse-biased avalanche diode for surge clamping, with forward conduction limited to ~3.5V (VF @ 12A). It does not provide symmetrical protection like a bidirectional TVS; for AC or differential-line protection, two unidirectional devices or a dedicated bidirectional part (e.g., DMLF40A) must be used.
Can DFLT40A-7 replace SMAJ40A in existing designs?
Yes, with layout adaptation: DFLT40A-7 uses PowerDI123 (2.8 × 1.8 mm), while SMAJ40A uses SMA (4.5 × 2.7 mm). Electrical replacement is valid-both have 40V VRWM and similar VBR-but DFLT40A-7 clamps 4.9V lower (64.5V vs. 69.4V) and offers superior thermal performance. Verify pad layout and solder profile compatibility before drop-in substitution.
Does DFLT40A-7 meet AEC-Q101 qualification?
No-DFLT40A-7 is not AEC-Q101 qualified. The automotive-grade variant is DFLT40AQ, which shares identical electrical specs but is manufactured in IATF 16949-certified facilities, undergoes extended reliability testing, and supports PPAP documentation. Use DFLT40AQ for production automotive applications; DFLT40A-7 is intended for industrial, computing, and consumer designs.
DFLT40A-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- POWERDI®123
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 3.49A
- Power - Peak Pulse:
- 225W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- PowerDI™ 123
DFLT40A-7 FAQ
1.How can I place an order for DFLT40A-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for DFLT40A-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 DFLT40A-7 reliable?
The price and inventory of DFLT40A-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DFLT40A-7 is usually 5 days.
3.What payment methods are accepted for DFLT40A-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DFLT40A-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DFLT40A-7?
DFLT40A-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DFLT40A-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 DFLT40A-7?
For technical support, including DFLT40A-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DFLT40A-7 requirements.
6.How does Aetrix verify that DFLT40A-7 is sourced from the original manufacturer or authorized distributors?
All DFLT40A-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 DFLT40A-7 meets industry standards.
7.What is the process for return or replacement of DFLT40A-7?
All DFLT40A-7 units undergo pre-shipment inspection (PSI). If there is an issue with DFLT40A-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 DFLT40A-7 part is unused and in its original packaging.
Return procedure for DFLT40A-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
DFLT40A-7 Tags
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Diodes Incorporated
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