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

Taiwan Semiconductor Corporation UF4004

Name: UF4004
Brand: Taiwan Semiconductor Corporation
SKU: UF4004
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: UF4004

Manufacturer:: Taiwan Semiconductor Corporation

Category:: Single Diodes

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

Datasheet:: UF4004.pdf

Description:: DIODE GEN PURP 400V 1A DO204AL

Quantity:: RFQ Add To RFQ list

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Inventory:4,863

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Product details

Overview

UF4004 from Taiwan Semiconductor is a 1A, 400V ultrafast recovery rectifier diode in DO-204AL (DO-41) package, featuring 50 ns reverse recovery time, 1.0 V forward voltage at 1 A, and 30 A surge current capability. It serves as a freewheeling or output rectifier in high-frequency switching power supplies.

For engineers reviewing the UF4004 datasheet, UF4004 pinout, UF4004 application, or UF4004 equivalent, key selection criteria include V_RRM = 400 V, t_rr = 50 ns, V_F = 1.0 V @ 1 A, thermal resistance R_θJL = 15 °C/W, and AEC-Q101 qualification availability in H-grade variants.

Technical Context

The UF4004 employs a glass-passivated silicon junction optimized for high-efficiency operation in DC–DC converters and SMPS topologies. Its ultrafast recovery enables reduced switching losses at frequencies up to several hundred kHz, while its 150 °C maximum junction temperature supports operation in thermally constrained environments.

Designed as a single-die, unidirectional device with cathode-band polarity marking, the UF4004 exhibits low junction capacitance (17 pF @ 4 V) and stable reverse leakage (≤5 µA @ 25 °C, ≤150 µA @ 125 °C), supporting reliable performance across industrial ambient temperature ranges.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	400 V - Maximum repetitive reverse voltage before breakdown; defines safe operating limit in flyback or boost output stages
t_rr	50 ns - Ultrafast reverse recovery time; minimizes switching loss and EMI in >100 kHz SMPS designs
V_F	1.0 V @ 1 A - Low forward voltage drop; reduces conduction loss and thermal load in continuous 1 A applications
I_FSM	30 A - Peak non-repetitive surge current; withstands inrush and transient overloads without failure
R_θJL	15 °C/W - Junction-to-lead thermal resistance; enables direct PCB copper pour heat sinking without heatsink
Junction Capacitance	17 pF @ 1 MHz, 4 V - Low capacitance minimizes capacitive coupling noise in high dv/dt gate-drive or snubber circuits

Pinout & Package

Package: DO-204AL (DO-41), axial leaded, glass-passivated silicon die, cathode indicated by band. Weight: 0.330 g. RoHS and halogen-free compliant.

Pin/Terminal	Circuit Role	Design Meaning
Anode (unbanded end)	Current entry terminal under forward bias	Connected to lower-potential node (e.g., switch node in flyback, ground return in freewheeling path)
Cathode (banded end)	Current exit terminal under forward bias; blocking terminal under reverse bias	Connected to higher-potential node (e.g., output rail, transformer secondary center-tap); defines polarity in rectification

Key Features

Feature	Design Value
Glass-passivated junction	Enhances moisture resistance and long-term reliability in humid or thermally cycling environments
AEC-Q101 qualification option (UF4004H)	Validated for automotive under-hood applications requiring robustness against vibration, thermal shock, and extended temperature life
Ultrafast 50 ns recovery	Enables efficient operation in high-frequency converters (>200 kHz) where slower diodes cause excessive loss and heating
Pure tin-plated leads	Ensures solderability per J-STD-002 and eliminates whisker growth risk per JESD201 Class 2

Applications

DC–DC Converter Output Rectification	Switch-Mode Power Supply Freewheeling
Use Scenario: Secondary-side rectification in isolated buck-derived topologies (e.g., forward, flyback) delivering 5–24 V at up to 1 A. IC Role / Device Role / Timing Role: Unidirectional current valve converting high-frequency AC from transformer secondary into regulated DC output. Use Value: 1.0 V V_F and 50 ns t_rr jointly reduce total power loss by ≥15% vs. standard fast recovery diodes at 100–300 kHz switching.	Use Scenario: Freewheeling path across inductive loads (e.g., solenoids, relay coils, motor windings) in industrial control modules. IC Role / Device Role / Timing Role: Clamp inductive kickback energy and provide low-impedance recirculation path during switch-off phase. Use Value: 30 A I_FSM safely absorbs short-duration inductive surges; 150 °C T_JMAX ensures stability during repeated actuation cycles.
AC–DC Adapter Secondary Rectification	High-Frequency Inverter Output Stage
Use Scenario: Output rectification in compact wall adapters (e.g., 12 V/1 A) using quasi-resonant or active-clamp flyback controllers. IC Role / Device Role / Timing Role: Synchronous or asynchronous rectifier handling continuous 1 A DC output with minimal voltage drop and ripple. Use Value: DO-41 package allows manual or automated through-hole assembly; 17 pF C_J limits high-frequency noise injection into feedback networks.	Use Scenario: Bridge-leg anti-parallel diode in 20–100 kHz inverters for UPS, solar microinverters, or motor drives. IC Role / Device Role / Timing Role: Provides reverse conduction path during dead-time intervals and commutates reactive current in inductive loads. Use Value: 50 ns t_rr prevents shoot-through risk in hard-switched bridges; 400 V V_RRM supports 24–48 V bus systems with safety margin.

DC–DC Converter Output Rectification

Switch-Mode Power Supply Freewheeling

Use Scenario: Secondary-side rectification in isolated buck-derived topologies (e.g., forward, flyback) delivering 5–24 V at up to 1 A.

IC Role / Device Role / Timing Role: Unidirectional current valve converting high-frequency AC from transformer secondary into regulated DC output.

Use Value: 1.0 V V_F and 50 ns t_rr jointly reduce total power loss by ≥15% vs. standard fast recovery diodes at 100–300 kHz switching.

Use Scenario: Freewheeling path across inductive loads (e.g., solenoids, relay coils, motor windings) in industrial control modules.

IC Role / Device Role / Timing Role: Clamp inductive kickback energy and provide low-impedance recirculation path during switch-off phase.

Use Value: 30 A I_FSM safely absorbs short-duration inductive surges; 150 °C T_JMAX ensures stability during repeated actuation cycles.

AC–DC Adapter Secondary Rectification

High-Frequency Inverter Output Stage

Use Scenario: Output rectification in compact wall adapters (e.g., 12 V/1 A) using quasi-resonant or active-clamp flyback controllers.

IC Role / Device Role / Timing Role: Synchronous or asynchronous rectifier handling continuous 1 A DC output with minimal voltage drop and ripple.

Use Value: DO-41 package allows manual or automated through-hole assembly; 17 pF C_J limits high-frequency noise injection into feedback networks.

Use Scenario: Bridge-leg anti-parallel diode in 20–100 kHz inverters for UPS, solar microinverters, or motor drives.

IC Role / Device Role / Timing Role: Provides reverse conduction path during dead-time intervals and commutates reactive current in inductive loads.

Use Value: 50 ns t_rr prevents shoot-through risk in hard-switched bridges; 400 V V_RRM supports 24–48 V bus systems with safety margin.

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultrafast rectifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STTH1R04 (STMicroelectronics)	V_RRM = 400 V, t_rr = 35 ns, V_F = 1.15 V @ 1 A, DO-41 package	Lower t_rr improves efficiency above 300 kHz but higher V_F increases conduction loss at full load	Select when prioritizing switching loss reduction over thermal budget in high-frequency designs
ES1D (ON Semiconductor)	V_RRM = 200 V, t_rr = 35 ns, V_F = 0.95 V @ 1 A, SMA surface-mount package	Half the V_RRM rating and SMT form factor limit use to low-voltage, space-constrained boards	Choose for compact 12–24 V DC–DC modules where board area is critical and voltage stress <200 V

Compared with STTH1R04 and ES1D, the UF4004 offers balanced trade-offs: sufficient 400 V rating for 24–48 V systems, proven 50 ns recovery for 100–250 kHz operation, and through-hole DO-41 compatibility for prototyping and industrial repairability.

Availability

UF4004 is available at Aetrix Electronics and suitable for DC–DC converters, switching mode power supplies, and freewheeling applications requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for UF4004 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 devices, and MOSFETs for industrial and automotive markets.

The UF400x series was developed to deliver cost-effective, high-reliability ultrafast rectification for mainstream switching power supplies, emphasizing thermal robustness, low-loss operation, and qualification-ready variants for automotive Tier-2 suppliers.

FAQ

What is the maximum repetitive peak reverse voltage (V_RRM) of the UF4004?

The UF4004 has a maximum repetitive peak reverse voltage (V_RRM) of 400 V. This rating defines the highest reverse-bias voltage the diode can block repeatedly without breakdown. It is validated per JEDEC standards and applies across the full operating temperature range of −55 °C to +150 °C. The UF4004 must not be operated beyond this voltage in any design using the UF4004.

What is the forward voltage drop (V_F) of the UF4004 at 1 A and 25 °C?

The forward voltage drop (V_F) of the UF4004 is 1.0 V at 1 A forward current and 25 °C junction temperature. This value is measured under pulsed conditions (0.3 ms pulse width) to minimize self-heating effects. At elevated temperatures or higher currents, V_F decreases slightly due to negative temperature coefficient behavior typical of silicon PN junctions. This specification is confirmed in the UF4004 electrical characteristics table.

Is the UF4004 suitable for automotive applications?

The standard UF4004 is not AEC-Q101 qualified, but the UF4004H variant is explicitly qualified to AEC-Q101 for automotive under-hood use. The H-grade version undergoes additional stress testing including temperature cycling, humidity bias, and mechanical shock. For automotive designs requiring qualification, specify UF4004H-not UF4004-when ordering. Both share identical electrical specs, but only UF4004H carries the AEC-Q101 certification documented in Taiwan Semiconductor's P2104 revision.

What is the reverse recovery time (t_rr) of the UF4004, and how is it measured?

The reverse recovery time (t_rr) of the UF4004 is 50 ns, measured under IF = 0.5 A, IR = 1.0 A, and Irr = 0.25 A per JEDEC test conditions. This parameter reflects the time required for minority carriers to clear the depletion region after forward conduction ceases. It is critical for minimizing switching loss and EMI in high-frequency power converters. The UF4004's 50 ns t_rr is verified in the "Electrical Specifications" section of the UF4004 datasheet (P2104).

What package type does the UF4004 use, and what are its mechanical features?

The UF4004 uses the DO-204AL (DO-41) axial-leaded package with glass-passivated chip junction and pure tin-plated leads. Its mechanical features include UL 94V-0 rated molding compound, cathode polarity indicated by a visible band, and compliance with JESD201 Class 2 whisker testing. The package weighs approximately 0.330 g and supports manual or wave-solder assembly. These attributes are specified in the "Mechanical Data" section of the UF4004 documentation.

UF4004 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

UF4004 FAQ

1.How can I place an order for UF4004 through Aetrix?

Please submit a Request for Quotation (RFQ) for UF4004 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 UF4004 reliable?

The price and inventory of UF4004 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UF4004 is usually 5 days.

3.What payment methods are accepted for UF4004?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UF4004 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for UF4004?

UF4004 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your UF4004 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 UF4004?

For technical support, including UF4004 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UF4004 requirements.

6.How does Aetrix verify that UF4004 is sourced from the original manufacturer or authorized distributors?

All UF4004 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 UF4004 meets industry standards.

7.What is the process for return or replacement of UF4004?

All UF4004 units undergo pre-shipment inspection (PSI). If there is an issue with UF4004, 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 UF4004 part is unused and in its original packaging.

Return procedure for UF4004:

1.Submit a request within 90 days.

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

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