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Home > Products > Discrete Semiconductor Products > Diodes > Rectifiers > Single Diodes

Taiwan Semiconductor Corporation UF1G

Name: UF1G
Brand: Taiwan Semiconductor Corporation
SKU: UF1G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: UF1G

Manufacturer:: Taiwan Semiconductor Corporation

Category:: Single Diodes

Package:: DO-204AL, DO-41, Axial

Datasheet:: UF1G.pdf

Description:: DIODE GEN PURP 400V 1A DO204AL

Quantity:: RFQ Add To RFQ list

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Inventory:4,937

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Product details

Overview

UF1G from Taiwan Semiconductor is a 1 A, 400 V repetitive peak reverse voltage (V_RRM) glass-passivated ultra-fast recovery rectifier diode in DO-204AL (DO-41) package, optimized for high-efficiency DC-DC converters and switching-mode inverters with soft recovery and low reverse recovery time. It operates up to 150°C junction temperature and delivers 1.0 V typical forward voltage at 1 A and 25°C.

For engineers reviewing the UF1G datasheet, UF1G pinout, UF1G application, or UF1G equivalent, key selection criteria include its 400 V V_RRM, 50 ns trr at IF = 0.5 A / IR = 1.0 A, 30 A IFSM surge rating, DO-41 mechanical compatibility, and AEC-Q101 qualification option (UF1GH).

Technical Context

This ultra-fast rectifier uses a single-die silicon PN junction with glass passivation for stable high-temperature operation and reduced leakage. Its soft recovery behavior minimizes EMI in high-frequency switching circuits, and the 17 pF junction capacitance at 1 MHz / 4 V supports efficient snubberless designs.

The device's thermal resistance of 15°C/W (junction-to-lead) enables reliable conduction at full 1 A DC current without forced cooling in standard PCB layouts, while the 60°C/W junction-to-ambient rating reflects typical DO-41 board-level dissipation limits.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	400 V - Maximum non-repetitive reverse blocking voltage; defines usable input voltage range in flyback or boost converters
I_F	1 A continuous - Rated average forward current at 75°C ambient; determines minimum heatsinking for steady-state operation
t_rr	50 ns - Measured at IF = 0.5 A, IR = 1.0 A, Irr = 0.25 A; enables >100 kHz switching with low turn-off loss
V_F	1.0 V max at IF = 1 A, TJ = 25°C - Low conduction loss improves efficiency in high-duty-cycle applications
I_FSM	30 A - Peak non-repetitive surge current (8.3 ms half-sine); withstands inrush and transient overloads
R_θJL	15 °C/W - Junction-to-lead thermal resistance; allows direct thermal path to copper pour or heatsink via lead frame

Pinout & Package

Package: DO-204AL (DO-41), axial-leaded, glass-passivated, RoHS-compliant, halogen-free molding compound (UL 94V-0), cathode indicated by band.

Pin/Terminal	Circuit Role	Design Meaning
Anode (unbanded end)	Forward current entry point	Connects to lower-potential node (e.g., switch node in buck converter or transformer secondary center-tap)
Cathode (banded end)	Forward current exit / reverse blocking terminal	Connects to output rail or filter capacitor; blocks reverse voltage up to 400 V

Key Features

Feature	Design Value
Ultra-fast recovery (t_rr ≤ 50 ns)	Reduces switching losses and EMI in 100–500 kHz SMPS topologies without requiring external snubbers
Glass-passivated junction	Ensures long-term reliability under thermal cycling and humidity exposure per JESD22-A101
Soft recovery characteristic	Minimizes voltage overshoot and ringing during diode turn-off, easing EMI filter design
AEC-Q101 qualified version available (UF1GH)	Validated for automotive powertrain and body electronics per stress test requirements

Applications

DC-DC Converters	Switching Inverters
Use Scenario: Secondary-side rectification in isolated 24 V–48 V input DC-DC modules for telecom and industrial power supplies. IC Role / Device Role / Timing Role: Ultra-fast freewheeling rectifier handling 1 A continuous output current with minimal conduction and switching loss. Use Value: 1.0 V V_F and 50 ns t_rr enable >92% efficiency at 200 kHz switching frequency without active synchronous rectification.	Use Scenario: Output stage freewheeling diode in 3-phase motor drive inverters operating at 10–20 kHz PWM. IC Role / Device Role / Timing Role: Clamp and recirculate inductive energy during IGBT/MOSFET dead-time intervals. Use Value: Soft recovery prevents voltage spikes exceeding 400 V rating during rapid current reversal, protecting switching devices.
Freewheeling Circuits	AC-DC Auxiliary Supplies
Use Scenario: Inductor current path in buck regulators powering FPGA core rails or microcontroller domains. IC Role / Device Role / Timing Role: Unidirectional current path during high-side switch off-time; handles peak currents up to 30 A surges. Use Value: 30 A IFSM rating absorbs load dump transients and startup inrush without degradation.	Use Scenario: Voltage-doubler or bridge rectifier in low-power auxiliary supplies (<5 W) for smart sensors and IoT gateways. IC Role / Device Role / Timing Role: Input rectifier converting 12–24 V AC or 17–34 V DC to unregulated DC bus. Use Value: 150°C max junction temperature and 5 µA IR at 25°C ensure stable operation in sealed enclosures with limited airflow.

DC-DC Converters

Switching Inverters

Use Scenario: Secondary-side rectification in isolated 24 V–48 V input DC-DC modules for telecom and industrial power supplies.

IC Role / Device Role / Timing Role: Ultra-fast freewheeling rectifier handling 1 A continuous output current with minimal conduction and switching loss.

Use Value: 1.0 V V_F and 50 ns t_rr enable >92% efficiency at 200 kHz switching frequency without active synchronous rectification.

Use Scenario: Output stage freewheeling diode in 3-phase motor drive inverters operating at 10–20 kHz PWM.

IC Role / Device Role / Timing Role: Clamp and recirculate inductive energy during IGBT/MOSFET dead-time intervals.

Use Value: Soft recovery prevents voltage spikes exceeding 400 V rating during rapid current reversal, protecting switching devices.

Freewheeling Circuits

AC-DC Auxiliary Supplies

Use Scenario: Inductor current path in buck regulators powering FPGA core rails or microcontroller domains.

IC Role / Device Role / Timing Role: Unidirectional current path during high-side switch off-time; handles peak currents up to 30 A surges.

Use Value: 30 A IFSM rating absorbs load dump transients and startup inrush without degradation.

Use Scenario: Voltage-doubler or bridge rectifier in low-power auxiliary supplies (<5 W) for smart sensors and IoT gateways.

IC Role / Device Role / Timing Role: Input rectifier converting 12–24 V AC or 17–34 V DC to unregulated DC bus.

Use Value: 150°C max junction temperature and 5 µA IR at 25°C ensure stable operation in sealed enclosures with limited airflow.

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-fast rectifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STTH1R04	Same 1 A / 400 V rating; 1.25 V V_F max; 50 ns t_rr; TO-220AC package	Higher thermal mass but requires mounting hardware; not DO-41 drop-in	Select when higher surge robustness and heatsink integration are prioritized over board space
ON Semi MUR140	1 A / 400 V; 1.25 V V_F max; 50 ns t_rr; DO-41 package; no AEC-Q101 variant	Identical footprint and polarity; lacks automotive qualification option	Select for cost-sensitive industrial designs where AEC-Q101 is not required

Compared with STTH1R04 and MUR140, UF1G offers lower forward voltage (1.0 V vs. 1.25 V), identical 50 ns recovery, DO-41 compatibility, and optional AEC-Q101 qualification-making it optimal for space-constrained, high-efficiency, or automotive-qualified designs.

Availability

UF1G is available at Aetrix Electronics and suitable for DC-DC converters, switching inverters, and freewheeling circuits requiring stable component supply, consistent parametric performance, and long-term manufacturing continuity.

Supply support for UF1G 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, specializing in power rectifiers, TVS diodes, MOSFETs, and LED drivers.

The UF1G belongs to TSC's UF1x ultra-fast rectifier family, engineered for high-efficiency, high-frequency switching power conversion in industrial, computing, and automotive auxiliary systems.

FAQ

What is the maximum repetitive peak reverse voltage (V_RRM) for UF1G?

The UF1G has a V_RRM of 400 V, meaning it reliably blocks up to 400 V of reverse voltage in repetitive applications such as switching power supply outputs. This rating is confirmed in the Absolute Maximum Ratings table of the official TSC datasheet (Version G2104) and applies specifically to the UF1G variant-not the entire UF1x series.

Does UF1G have AEC-Q101 qualification?

The base UF1G is not AEC-Q101 qualified, but the pin-compatible UF1GH variant is explicitly listed as AEC-Q101 qualified in TSC's ordering information. UF1GH uses the same die and DO-41 package, with added automotive stress testing-making it suitable for automotive body electronics and ADAS auxiliary supplies.

What is the forward voltage (V_F) of UF1G at rated current?

At I_F = 1 A and T_J = 25°C, the UF1G exhibits a maximum forward voltage of 1.0 V, with typical values lower. This parameter is specified in the Electrical Specifications table and directly impacts conduction loss and thermal rise in high-duty-cycle applications like buck converter freewheeling paths.

What is the reverse recovery time (t_rr) of UF1G and how is it tested?

The UF1G has a maximum t_rr of 50 ns, measured under conditions of I_F = 0.5 A, I_R = 1.0 A, and I_rr = 0.25 A, per the test circuit shown in Figure 6 of the TSC datasheet. This ultra-fast recovery enables clean turn-off in high-frequency SMPS without excessive voltage overshoot.

Is UF1G compatible with lead-free reflow soldering processes?

Yes, UF1G features pure tin-plated leads compliant with J-STD-002 for solderability and rated for lead-free reflow profiles (peak temperature ≤ 260°C). The DO-41 package and UL 94V-0 molding compound are fully compatible with standard IPC/JEDEC J-STD-020 moisture sensitivity level (MSL) handling.

UF1G Specifications

Product attributes: Attribute value

Manufacturer:: Taiwan Semiconductor Corporation

Series:: -

Package/Case:: DO-204AL, DO-41, Axial

Packaging:: Tape & Reel (TR)

Product Status:: Active

Technology:: Standard

Voltage - DC Reverse (Vr) (Max):: 400 V

Current - Average Rectified (Io):: 1A

Voltage - Forward (Vf) (Max) @ If:: 1 V @ 1 A

Speed:: Fast Recovery =< 500ns, > 200mA (Io)

Reverse Recovery Time (trr):: 50 ns

Current - Reverse Leakage @ Vr:: 5 µA @ 400 V

Capacitance @ Vr, F:: 17pF @ 4V, 1MHz

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: DO-204AL (DO-41)

Operating Temperature - Junction:: -55°C ~ 150°C

UF1G FAQ

1.How can I place an order for UF1G through Aetrix?

Please submit a Request for Quotation (RFQ) for UF1G 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 UF1G reliable?

The price and inventory of UF1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UF1G is usually 5 days.

3.What payment methods are accepted for UF1G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UF1G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for UF1G?

UF1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your UF1G 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 UF1G?

For technical support, including UF1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UF1G requirements.

6.How does Aetrix verify that UF1G is sourced from the original manufacturer or authorized distributors?

All UF1G 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 UF1G meets industry standards.

7.What is the process for return or replacement of UF1G?

All UF1G units undergo pre-shipment inspection (PSI). If there is an issue with UF1G, 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 UF1G part is unused and in its original packaging.

Return procedure for UF1G:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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