Diodes Incorporated MB3505

Overview

MB3505 from Diodes Incorporated is a high-current silicon bridge rectifier with 35 A average output current, 50 V maximum recurrent peak reverse voltage, and 1.2 V forward voltage drop at 17.5 A, designed for AC-to-DC conversion in industrial power supplies and motor drive front-ends.

For engineers reviewing the MB3505 datasheet, MB3505 pinout, MB3505 application, or MB3505 equivalent, key selection criteria include thermal resistance (2.5 °C/W junction-to-case), faston terminal mounting compatibility, 400 A non-repetitive surge rating, and UL 94V-0 case flammability compliance.

Technical Context

This single-phase full-wave bridge rectifier integrates four silicon diodes in a metal-cased package optimized for bolt-down heat-sink mounting with silicone thermal compound. It operates across –55 °C to +150 °C junction temperature range and supports 60 Hz resistive or inductive loads.

Rated for 35 A average rectified output at case temperature ≤55 °C, it delivers stable DC output under sustained load with 664 A²s I²t fusing rating and <1.0 µA reverse leakage at 25 °C - critical for low-loss, high-reliability power conversion stages.

Key Specifications

Pinout & Package

MB3505 uses a metal-case, bolt-down package with four universal terminals: two AC inputs (marked "AC"/"~"), one positive DC output (+), and one negative DC output (–). Mounting requires #10 screw, 20 in·lb torque, and silicone thermal interface to heatsink.

Key Features

Applications

Equivalent & Alternatives

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

Compared with GBPC3505 and KBPC3505, MB3505 uniquely combines UL 94V-0 case material, 2.5 °C/W R_JC, and standardized 0.25" faston terminals - making it the only option qualified for bolt-down, safety-critical, and service-accessible power conversion systems.

Availability

MB3505 is available at Aetrix Electronics and suitable for industrial AC/DC power supplies, motor drive front-ends, and welding equipment requiring stable component supply and long-term mechanical serviceability.

Supply support for MB3505 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, manufacturing, and sales operations across Asia, Europe, and North America.

The MB-series bridge rectifiers are engineered for high-power, high-reliability AC/DC conversion in industrial, automotive, and infrastructure applications - emphasizing thermal robustness, mechanical durability, and regulatory compliance.

FAQ

What is the recommended mounting method for MB3505?

MB3505 must be bolted directly to a heatsink using a #10 screw at maximum 20 in·lb torque, with silicone thermal compound applied between the metal case and heatsink surface. This configuration achieves the specified 2.5 °C/W junction-to-case thermal resistance and prevents thermal runaway under full-load conditions.

Is MB3505 RoHS compliant and lead-free?

Yes - MB3505 features a lead-free finish and complies with EU Directive 2002/95/EC (RoHS), effective for date codes 0514 and later. Exemptions for glass and high-temperature solder are applied per Annex Notes 5 and 7 of the directive, confirmed in the official Diodes Incorporated datasheet DS21303 Rev. 7.

Can MB3505 replace MB3505W in a design?

No - MB3505 uses universal faston/solder terminals, while MB3505W has wire leads. The mechanical interface, mounting method, and thermal path differ significantly. Substitution requires redesign of the interconnect and heatsink interface; they are not functionally interchangeable without layout changes.

Why is MB3505 marked "Not Recommended for New Design"?

Diodes Incorporated recommends the GBPC35 series for new designs due to improved packaging efficiency and broader distribution channel support. However, MB3505 remains fully manufactured, stocked, and supported for legacy system maintenance, repair, and applications requiring its unique metal-case mechanical and thermal attributes.