Diodes Incorporated SD945-T

Overview

SD945-T from Diodes Incorporated is a high-current Schottky barrier rectifier in DO-201AD package, rated for 45 V peak repetitive reverse voltage, 9.0 A average forward current at TC = 120°C, and 340 A non-repetitive surge current. It delivers low forward voltage drop (0.52 V at 18 A, TJ = 125°C), low thermal resistance (8.0 K/W junction-to-lead), and operates from –65°C to +150°C - used in high-efficiency AC/DC front-end rectification for industrial power supplies.

For engineers reviewing the SD945-T datasheet, SD945-T pinout, SD945-T application, or SD945-T equivalent, key selection criteria include its 45 V VRWM rating, 9.0 A IO capability with heatsink mounting, 0.52 V VF at high temperature and high current, surge robustness (340 A IFSM), and RoHS-compliant tin-plated leads solderable per MIL-STD-202.

Technical Context

This device functions as a unidirectional power rectifier optimized for high-current, low-loss DC output stages. Its guard-ringed die structure provides transient overvoltage protection, while the low RθJL (8.0 K/W) enables effective heat conduction to PCB leads or heatsinks under sustained 9.0 A load.

Designed for single-phase, half-wave 60 Hz operation with resistive or inductive loads, it requires 20% current derating for capacitive loads. Electrical behavior is characterized under short-pulse conditions (≤2% duty cycle) to suppress self-heating effects during VF and IR measurement.

Key Specifications

Pinout & Package

Package: DO-201AD molded plastic case (UL 94V-0), cathode indicated by band, polarity-sensitive axial leaded configuration, weight ≈1.1 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VS-9CPH04-M3 and MBR1045CT, SD945-T offers superior thermal integration via DO-201AD lead conduction (RθJL = 8.0 K/W), lower VF at high temperature, and compact through-hole footprint - ideal for cost- and space-sensitive industrial rectifiers where heatsinkless operation is prioritized.

Availability

SD945-T is available at Aetrix Electronics and suitable for industrial AC/DC power supplies, telecom rectifier modules, and LED driver front-ends requiring stable component supply, long-lifecycle support, and RoHS-compliant manufacturing.

Supply support for SD945-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 high-reliability power, signal integrity, and protection solutions for industrial, computing, and communications markets.

The SD9xx series belongs to Diodes' high-current Schottky rectifier product line, engineered specifically for efficiency-critical AC/DC and DC/DC conversion stages where low VF, high surge tolerance, and robust thermal performance are mandatory.

FAQ

What is the maximum allowable case temperature for continuous operation of SD945-T?

The SD945-T is rated for 9.0 A average forward current at TC = 120°C. Operation above this temperature requires current derating per Figure 1 in the datasheet. Sustained case temperatures beyond 120°C risk exceeding the 150°C maximum junction temperature, especially under high IF and poor thermal coupling.

Can SD945-T be used in capacitive-input filter configurations without modification?

No - the datasheet explicitly requires a 20% reduction in rated average forward current when used with capacitive loads. This derating compensates for higher peak currents drawn during capacitor charging, which increase thermal stress and accelerate wear-out.

Is SD945-T compatible with lead-free reflow soldering processes?

Yes. SD945-T features tin-plated leads compliant with RoHS Directive 2002/95/EC (as revised), and its terminals are solderable per MIL-STD-202, Method 208. It supports standard Pb-free reflow profiles with peak temperatures up to 260°C, provided moisture sensitivity level 1 handling guidelines are followed.

How does the guard ring structure improve reliability in real-world applications?

The guard ring mitigates electric field crowding at the silicon periphery, preventing premature avalanche and surface leakage under transient overvoltage events such as lightning-induced surges or inductive kickback. This extends operational life in unprotected AC mains interfaces and motor drive snubber circuits.