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Taiwan Semiconductor Corporation 31DF4
- Part No.:
- 31DF4
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- Single Diodes
- Package:
- DO-201AD, Axial
- Datasheet:
-
31DF4.pdf
- Description:
- DIODE GEN PURP 400V 3A DO201AD
- Quantity:
- Payment:
- Shipping:
Inventory:2,378
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Product details
Overview
31DF4 from Taiwan Semiconductor is a 3A, 400V super fast rectifier diode in DO-201AD package, featuring 35ns reverse recovery time, 1.7V forward voltage at 3A, and 45A surge capability - deployed in DC-DC converters and switching inverters for high-efficiency power conversion.
For engineers reviewing the 31DF4 datasheet, 31DF4 pinout, 31DF4 application, or 31DF4 equivalent, key selection criteria include repetitive peak reverse voltage (400V), thermal resistance (80°C/W), junction temperature range (–55°C to +150°C), RoHS/halogen-free compliance, and DO-201AD mechanical compatibility with standard through-hole layouts.
Technical Context
This single-die super fast rectifier uses optimized PN junction design to achieve low VF and rapid carrier recombination, enabling efficient operation in high-frequency switching topologies. Its 35ns trr and 45A IFSM support hard-switched SMPS and freewheeling paths where fast turn-off and surge resilience are critical.
The device operates across –55°C to +150°C junction temperature, with thermal resistance RθJA = 80°C/W enabling reliable performance in compact, convection-cooled designs. Pure tin-plated leads meet J-STD-002 solderability and JESD 201 Class 1A whisker requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 400 V - Maximum repetitive reverse blocking voltage; defines safe operating limit in DC-DC output rectification |
| IF | 3 A - Continuous average forward current; sets steady-state power handling capacity at TA = 25°C |
| trr | 35 ns - Reverse recovery time; enables stable operation up to ~3 MHz switching frequencies in hard-switched converters |
| VF @ 3A | 1.7 V - Forward voltage drop at rated current; directly determines conduction loss (5.1 W at 3A) |
| IFSM | 45 A - Non-repetitive surge current (8.3 ms half-sine); supports inrush and fault-current tolerance |
| RθJA | 80 °C/W - Junction-to-ambient thermal resistance; informs heatsinking needs for 150°C max TJ operation |
Pinout & Package
DO-201AD axial-leaded package with cathode band marking; two-terminal configuration (anode and cathode) in standard through-hole outline per JEDEC DO-201AD.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry point | Connected to lower-potential side of circuit; must withstand full forward surge during conduction |
| Cathode | Forward current exit / reverse blocking terminal | Marked by band; carries full reverse voltage during off-state and interfaces with output filter capacitor |
Key Features
| Feature | Design Value |
|---|---|
| Super fast recovery | 35 ns trr enables high-frequency SMPS operation without excessive switching loss or ringing |
| Low forward voltage | 1.7 V at 3A reduces conduction loss by ~15% vs. standard fast rectifiers with VF > 1.9 V |
| High surge rating | 45 A IFSM supports transient overloads in motor drives and UPS systems without failure |
| RoHS & halogen-free | Complies with IEC 61249-2-21; suitable for consumer and industrial products requiring green manufacturing |
Applications
| DC-DC Converter Output Rectification | Switching Inverter Freewheeling Path |
|---|---|
Use Scenario: Secondary-side rectification in isolated flyback or forward converters delivering 12–48 V outputs. IC Role / Device Role / Timing Role: Power diode conducting during transformer reset phase; handles continuous 3A DC output current. Use Value: Low VF minimizes power loss; 35ns trr prevents reverse recovery-induced cross-conduction in synchronous designs. | Use Scenario: Freewheeling path across inductive loads (e.g., BLDC motor phases or solenoid drivers) in H-bridge inverters. IC Role / Device Role / Timing Role: Provides low-loss return path during PWM off-time; clamps inductive kickback voltage. Use Value: 45A IFSM absorbs energy from high-L loads; 400V VRRM safely blocks bus voltage spikes up to 350V DC bus. |
| AC-DC Adapter Secondary Rectifier | Industrial SMPS Input Bridge Leg |
Use Scenario: Output rectification in universal-input 5–20 W AC-DC adapters powering IoT sensors and smart home devices. IC Role / Device Role / Timing Role: Single-phase rectifier converting transformer secondary AC to regulated DC; operates at 50–100 kHz. Use Value: DO-201AD package allows manual or wave soldering; 1.2 g weight supports lightweight portable design. | Use Scenario: One leg of a discrete bridge rectifier in 30–100 W industrial SMPS front-end stages. IC Role / Device Role / Timing Role: Handles half-wave rectified line frequency input with high surge margin during cold start. Use Value: 45A IFSM accommodates 10× inrush surges; –55°C to +150°C TJ range ensures reliability in unventilated enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar super fast rectifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STTH3L04 | VRRM = 400 V, IF = 3 A, trr = 30 ns, VF = 1.65 V - slightly faster and lower VF | Same DO-201AD footprint; higher IR (50 µA @ 125°C vs. 100 µA for 31DF4) | Preferred where minimal trr and VF are prioritized over worst-case leakage at elevated temperature |
| ES3D | VRRM = 200 V, IF = 3 A, trr = 35 ns, VF = 1.7 V - lower voltage rating, same speed and drop | Not suitable for 400V bus applications; limited to ≤200V DC systems | Select only when system maximum reverse voltage remains below 200V; otherwise risk catastrophic failure |
Compared with STTH3L04 and ES3D, the 31DF4 offers balanced trade-offs: identical trr and VF to ES3D but with 2× VRRM headroom, and slightly higher IR than STTH3L04 while maintaining broader temperature stability and lower cost in volume procurement.
Availability
31DF4 is available at Aetrix Electronics and suitable for DC-DC converters, switching mode inverters, and freewheeling applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant manufacturing.
Supply support for 31DF4 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving global power and protection markets since 1979.
The 31DF4 belongs to TSC's Super Fast Rectifier family, engineered specifically for high-efficiency, high-reliability power conversion in industrial, computing, and consumer switching power supplies.
FAQ
What is the maximum junction temperature rating for the 31DF4?
The 31DF4 has a maximum junction temperature (TJ) of +150°C and a minimum of –55°C. This wide operating range allows deployment in sealed industrial enclosures and automotive under-hood environments where ambient temperatures exceed 85°C. Derating curves in the datasheet confirm usable current capacity down to zero amps at 150°C ambient with proper PCB copper area.
Does the 31DF4 have a cathode band marking, and how is polarity identified?
Yes, the 31DF4 uses a visible cathode band on the DO-201AD body to indicate polarity - the banded end is the cathode terminal. This marking aligns with JEDEC standards and ensures correct orientation during manual or automated assembly. The band is laser-etched or molded into the epoxy, remaining legible after wave soldering and conformal coating.
What is the reverse recovery time (trr) specification for the 31DF4, and under what test conditions is it measured?
The 31DF4 has a maximum reverse recovery time (trr) of 35 ns, measured under IF = 0.5 A, IR = 1.0 A, and Irr = 0.25 A per the datasheet. This value reflects performance in hard-switched topologies and is validated using standardized pulse test circuits shown in Figure 6 of the TSC G2105 document. Typical trr is not specified - only the guaranteed max.
Is the 31DF4 compliant with RoHS and halogen-free requirements?
Yes, the 31DF4 is RoHS compliant and halogen-free per IEC 61249-2-21. The molding compound meets UL 94V-0 flammability rating, and the pure tin-plated leads satisfy J-STD-002 solderability and JESD 201 Class 1A whisker resistance. Full compliance documentation is available upon request from Aetrix Electronics for audit or certification purposes.
What packaging options are available for the 31DF4?
The 31DF4 is supplied in two standard configurations: 1,250 units per 12 mm tape-and-reel (ordering code 31DF4) and 500 units per ammo box (ordering code 31DF4 A0G). Both use DO-201AD packaging and are compatible with pick-and-place equipment and wave soldering processes. Reel packaging includes ESD-safe cover tape and embossed carrier tape per EIA-481-D.
31DF4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Series:
- -
- Package/Case:
- DO-201AD, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 400 V
- Current - Average Rectified (Io):
- 3A
- Voltage - Forward (Vf) (Max) @ If:
- 1.7 V @ 3 A
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- 35 ns
- Current - Reverse Leakage @ Vr:
- 20 µA @ 400 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-201AD
- Operating Temperature - Junction:
- -40°C ~ 150°C
31DF4 FAQ
1.How can I place an order for 31DF4 through Aetrix?
Please submit a Request for Quotation (RFQ) for 31DF4 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 31DF4 reliable?
The price and inventory of 31DF4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 31DF4 is usually 5 days.
3.What payment methods are accepted for 31DF4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 31DF4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 31DF4?
31DF4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 31DF4 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 31DF4?
For technical support, including 31DF4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 31DF4 requirements.
6.How does Aetrix verify that 31DF4 is sourced from the original manufacturer or authorized distributors?
All 31DF4 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 31DF4 meets industry standards.
7.What is the process for return or replacement of 31DF4?
All 31DF4 units undergo pre-shipment inspection (PSI). If there is an issue with 31DF4, 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 31DF4 part is unused and in its original packaging.
Return procedure for 31DF4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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