Diodes Incorporated SBR20A45CT

Overview

SBR20A45CT from Diodes Incorporated is a 20A dual common-cathode super barrier rectifier in TO-220AB package, rated for 45V peak reverse voltage, with typical forward voltage of 0.47V at 10A/25°C and 0.60V at 20A/25°C, designed for high-efficiency AC/DC and DC/DC power conversion stages in industrial SMPS.

For engineers reviewing the SBR20A45CT datasheet, SBR20A45CT pinout, SBR20A45CT application, or SBR20A45CT equivalent, key selection criteria include forward voltage drop at full load, thermal resistance (2°C/W junction-to-case), leakage current at 125°C, soft-switching behavior, and TO-220AB mechanical compatibility with standard heatsinks.

Technical Context

This dual-leg super barrier rectifier integrates two independent anode terminals sharing a common cathode, enabling synchronous half-wave or center-tap full-wave configurations. Its patented SBR technology replaces conventional Schottky or fast recovery diodes by combining low VF with superior high-temperature stability and reduced reverse recovery charge.

Unlike standard PN junction rectifiers, it exhibits soft reverse recovery with minimal ringing under hard switching, and maintains <100µA leakage at 45V and +125°C - critical for standby efficiency in energy-compliant power supplies.

Key Specifications

Pinout & Package

TO-220AB package with isolated tab (cathode-connected metal flange), 3-terminal configuration: Pin 1 = Anode 1, Pin 2 = Cathode (common, electrically connected to tab), Pin 3 = Anode 2. Mounting hole centered on tab allows direct heatsink attachment with electrical isolation required if cathode is not chassis-ground referenced.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SBRT20A45CT, SBR20A45CT trades 0.2°C/W higher thermal resistance and looser VF tolerance for broader availability and lower unit cost; versus MBR2045CT, it delivers measurable efficiency and thermal advantages in thermally constrained or energy-certified designs.

Availability

SBR20A45CT is available at Aetrix Electronics and suitable for industrial SMPS, telecom power shelves, LED drivers, and server PSU output stages requiring stable component supply, RoHS compliance, and verified thermal performance.

Supply support for SBR20A45CT 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 centers across Asia and manufacturing in China, Taiwan, and the U.S.

The SBR® product line was developed specifically for high-efficiency, high-reliability power conversion - targeting applications where Schottky VF drift and PN junction leakage compromise efficiency or thermal design margins.

FAQ

Is the metal tab of SBR20A45CT electrically connected to the cathode?

Yes, the TO-220AB metal tab is internally bonded to the common cathode (Pin 2). When mounting to a heatsink, an insulating washer and shoulder washer must be used unless the cathode node is intentionally tied to chassis ground. Electrical isolation is required for floating-output or multi-rail systems.

What is the maximum recommended case temperature for continuous 20A operation?

At 20A total (10A per leg), the maximum allowable case temperature is +115°C to maintain junction temperature ≤+150°C, assuming RθJC = 2°C/W and no additional interface resistance. With standard thermal paste and 10cm² aluminum heatsink, sustained 20A operation is feasible up to +70°C ambient.

Can SBR20A45CT replace MBR2045CT without circuit modification?

Yes - it is a direct drop-in replacement with identical pinout, package, and voltage rating. However, its lower VF reduces conduction loss and thermal stress, so existing heatsink sizing may become over-specified; verify thermal margin using actual measured VF and load profile before qualification.

Does SBR20A45CT require derating for capacitive loads?

Yes - the datasheet specifies a 20% current derating for capacitive loads due to high inrush current stress. At full 20A rating, the device must be operated at ≤16A when feeding bulk capacitance directly, or paired with inrush-limiting circuitry such as NTC thermistors or active pre-charge stages.