SMC Diode Solutions MBR1045

Overview

MBR1045 from Diodes Incorporated is a 10A, 45V Schottky barrier rectifier in TO-220AC package, designed for low-voltage, high-frequency DC/DC conversion, freewheeling, and polarity protection. It delivers 0.95V forward voltage at 10A/25°C, 150A non-repetitive surge capability, and 0.1mA peak reverse current at rated blocking voltage.

For engineers reviewing the MBR1045 datasheet, MBR1045 pinout, MBR1045 application, or MBR1045 equivalent, key selection criteria include its 45V VRRM rating, thermal resistance of 2.5°C/W (junction-to-case), TO-220AC mounting compatibility, and suitability for 12V/24V automotive power rails and SMPS output stages.

Technical Context

This Schottky diode uses guard ring die construction to enhance transient robustness and suppress avalanche-induced failure. Its low forward voltage drop directly reduces conduction losses in high-current switching paths, while its 400pF typical junction capacitance supports operation up to several MHz in flyback and synchronous rectifier topologies.

The device operates across –65°C to +150°C with derated current above +125°C case temperature. Thermal performance relies on heatsink mounting-its 2.5°C/W RθJC enables stable 10A continuous operation only when properly heatsinked per Figure 1 derating curve.

Key Specifications

Pinout & Package

Package: TO-220AC - Molded plastic case, UL 94V-0 rated, with tin-plated terminals solderable per MIL-STD-202. Mounting via tab (cathode) to heatsink required for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VS-MBR1045 and M1045T, the MBR1045 offers the lowest IRM (0.1mA) for ultra-low-power hold-up and best thermal resistance (2.5°C/W), making it preferred for automotive and industrial designs demanding long-term reliability under thermal stress.

Availability

MBR1045 is available at Aetrix Electronics and suitable for automotive power distribution, industrial SMPS output stages, solar charge controller inputs, and LED driver polarity guard circuits requiring stable component supply despite its obsolete status.

Supply support for MBR1045 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 management and signal integrity solutions for automotive, industrial, and consumer markets.

The MBR10xx series belongs to Diodes' Schottky rectifier product line, engineered specifically for high-current, low-loss DC/DC conversion and reverse-polarity protection in harsh-environment power systems.

FAQ

Is MBR1045 still in active production?

No-MBR1045 is officially obsolete per Diodes Incorporated's DS23009 Rev. 11 (June 2015). However, Aetrix Electronics maintains legacy inventory with full traceability and offers lifecycle coordination support to extend design viability through last-time buys and cross-qualified alternatives.

Can MBR1045 be used without a heatsink?

No. At 10A average current, junction temperature exceeds safe limits without heatsinking due to 2.5°C/W RθJC and 9.5W conduction loss. Derating to ≤2.5A is required for unheatsinked operation at +25°C ambient, per Figure 1 derating curve.

What is the cathode connection configuration in TO-220AC?

In MBR1045's TO-220AC package, the metal tab is the cathode and electrically connected to Pins 2 and 3. Pin 1 is the anode. The tab must be electrically isolated from chassis ground unless circuit topology explicitly references cathode to system ground.

How does MBR1045 compare to silicon PN rectifiers like 1N5408?

MBR1045 replaces 1N5408 in high-efficiency applications: it cuts forward voltage from ~0.95V (at lower current) to 0.95V at 10× higher current, eliminates reverse recovery time (no switching loss), and sustains 150A surge vs. 1N5408's 200A-but with far lower thermal impedance and no minority-carrier storage delay.