Diodes Incorporated SR305-T

Overview

SR305-T from Diodes Incorporated is a high-current Schottky barrier rectifier in DO-201AD axial package, rated for 50 V DC blocking voltage, 3.0 A average forward current at 95°C lead temperature, and 80 A non-repetitive surge current (8.3 ms half-sine). It delivers low forward voltage drop (0.55 V @ 3.0 A) and low thermal resistance (20 °C/W), enabling efficient power conversion in offline AC/DC front-end and DC-DC secondary-side rectification.

For engineers reviewing the SR305-T datasheet, SR305-T pinout, SR305-T application, or SR305-T equivalent, key selection factors include its 50 V VRRM rating, 0.55 V VF at 3.0 A, 300 pF junction capacitance at 4 V reverse bias, -65 to +150 °C operating range, and DO-201AD mechanical compatibility with legacy axial-mount power supplies.

Technical Context

This device operates as a unidirectional power rectifier using a planar Schottky barrier structure optimized for low conduction loss and fast switching. Its guard ring design enhances transient voltage immunity without compromising forward performance, and the DO-201AD package supports vertical PCB mounting with 1.27 mm lead length for validated thermal resistance of 20 °C/W.

Electrical behavior is characterized under single-phase, half-wave, 60 Hz resistive/inductive load conditions; capacitive loads require 20% current derating. The 300 pF typical junction capacitance (measured at 1 MHz, 4.0 V reverse bias) limits high-frequency switching use but suits line-frequency and low-MHz DC-DC applications.

Key Specifications

Pinout & Package

DO-201AD molded plastic axial-leaded package per UL 94V-0 flammability rating; moisture sensitivity Level 1; cathode identified by band; weight ≈1.2 g.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-current Schottky rectifier applications.

Compared with SB350-T and SS35, SR305-T offers balanced VF/IR trade-off and proven axial-mount compatibility for legacy repair and low-volume industrial builds-making it optimal where mechanical fit and thermal derating predictability are prioritized over marginal efficiency gains or SMT transition.

Availability

SR305-T is available at Aetrix Electronics and suitable for AC/DC adapter front-ends, industrial power supply input stages, and LED driver bulk rectification requiring stable component supply and long-term obsolescence management.

Supply support for SR305-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, specializing in power management, signal integrity, and protection devices for industrial, computing, and consumer markets.

SR305-T belongs to the SR3xx series of high-current Schottky rectifiers designed specifically for cost-sensitive, thermally constrained line-frequency rectification where low VF and axial mechanical compatibility are essential.

FAQ

What is the maximum allowable junction temperature for SR305-T?

The SR305-T has a maximum junction temperature (TJ) of +150 °C, consistent with its specified operating and storage range of -65 to +150 °C. This limit governs thermal design: with 20 °C/W RJA and 1.65 W conduction loss (at 3.0 A, 0.55 V), ambient must stay below 117 °C to avoid exceeding TJmax under steady-state conditions.

Can SR305-T replace a standard silicon rectifier like 1N5408 in a 50 V application?

Yes, SR305-T can replace 1N5408 in 50 V-rated circuits, offering significantly lower VF (0.55 V vs. ~0.9 V), reduced conduction loss, and faster recovery. However, its higher reverse leakage (1.0 mA @ 25°C) and lower VRRM margin (50 V vs. 1N5408's 1000 V) require verification that system reverse stresses remain within 50 V and leakage is acceptable in standby modes.

Is SR305-T suitable for high-frequency switching applications above 100 kHz?

No-SR305-T is not recommended for high-frequency switching above 100 kHz due to its 300 pF junction capacitance and lack of specified reverse recovery time. Its electrical characterization targets 50/60 Hz and low-kHz DC-DC use; for >100 kHz, consider low-Ct Schottky diodes like the SB350 series or SMD alternatives with sub-100 pF capacitance.

Does SR305-T comply with RoHS and REACH requirements?

Yes, SR305-T is RoHS-compliant (Pb-free, per Diodes Incorporated documentation) and meets REACH SVHC thresholds. The DO-201AD package uses halogen-free molding compound compliant with UL 94V-0, and all materials declarations are available in Diodes' official compliance database under part number SR305-T.