Diodes Incorporated UF1004-T

Overview

UF1004-T from Diodes Incorporated is a 1.0A ultra-fast rectifier diode with 400V peak repetitive reverse voltage (VRRM), 1.3V forward voltage at 1.0A, 50ns reverse recovery time (trr), and DO-41 package - designed for high-frequency switching power supplies, DC-DC converters, and snubber circuits requiring fast recovery and low conduction loss.

For engineers reviewing the UF1004-T datasheet, UF1004-T pinout, UF1004-T application, or UF1004-T equivalent, key selection criteria include VRRM rating, trr performance under 60Hz/switching loads, thermal resistance (RθJA = 95 K/W), and compatibility with automated through-hole assembly in industrial power supplies.

Technical Context

This diffused-junction silicon rectifier supports single-phase, half-wave rectification at 60Hz with derating for capacitive loads (−20% current). It operates across −65°C to +150°C junction temperature range and meets UL 94V-0 flammability standard.

Reverse recovery is characterized with IF = 0.5A, IR = 1.0A, and Irr = 0.25A per Figure 5; junction capacitance is 20pF at 4.0V reverse bias and 1.0MHz, confirming suitability for >100kHz switching topologies.

Key Specifications

Pinout & Package

DO-41 axial-leaded plastic package with cathode band marking; leads are tin-plated, solderable per MIL-STD-202 Method 208. Mechanical dimensions: length 25.40 mm max, body diameter 4.06–5.21 mm, lead diameter 0.71–0.864 mm, lead spacing 2.00–2.72 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STTH1L06 and ES1D, UF1004-T offers optimal balance of 400V rating, 50ns speed, and through-hole manufacturability - making it ideal for cost-sensitive, medium-voltage industrial power supplies where rework tolerance and legacy assembly lines matter.

Availability

UF1004-T is available at Aetrix Electronics and suitable for AC/DC adapters, DC-DC converters, and motor drive protection circuits requiring stable component supply and long-term production continuity.

Supply support for UF1004-T 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 and manufacturing operations across Asia and the US.

The UF100x series targets high-efficiency, cost-optimized power conversion in consumer, industrial, and computing applications - emphasizing fast recovery, robust surge handling, and standardized through-hole packaging.

FAQ

What is the maximum allowable junction temperature for UF1004-T?

The absolute maximum junction temperature is +150°C, and the storage temperature range matches this. Operation above 125°C requires derating of average forward current per Figure 1, where current drops linearly from 1.0A at 55°C to ~0.4A at 125°C ambient.

Can UF1004-T replace UF1002 in an existing design?

Yes, provided the circuit's peak reverse voltage does not exceed 400V. UF1004-T has higher VRRM (400V vs. 100V) and identical package, pinout, and thermal characteristics - offering improved margin against transients without layout changes.

Is UF1004-T suitable for synchronous rectification designs?

No - UF1004-T is a passive diode and cannot be actively controlled. It serves only as a freewheeling or rectifying element in non-synchronous topologies; synchronous designs require gate-driven MOSFETs with precise timing control.

How does UF1004-T perform under capacitive load conditions?

Per datasheet note, average forward current must be derated by 20% under capacitive loading due to higher peak currents. At 55°C ambient, IO is reduced from 1.0A to 0.8A to ensure reliable operation and prevent thermal runaway.