Vishay General Semiconductor - Diodes Division GBU8K-M3/45

Overview

GBU8K-M3/45 from Vishay General Semiconductor is a glass-passivated single-phase bridge rectifier with 800 V maximum repetitive peak reverse voltage (V_RRM), 8.0 A average forward output current (I_F(AV)), and 200 A non-repetitive peak surge current (I_FSM). It features 1.0 V forward voltage drop at 8.0 A, 5 μA reverse leakage at 25 °C, and is rated for operation from –55 °C to +150 °C junction temperature - used in AC/DC power conversion for switching mode power supplies and consumer electronics.

For engineers reviewing the GBU8K-M3/45 datasheet, GBU8K-M3/45 pinout, GBU8K-M3/45 application, or GBU8K-M3/45 equivalent, key selection criteria include V_RRM = 800 V, I_F(AV) = 8.0 A at T_C = 60 °C, thermal resistance R_θJC = 4.0 °C/W, UL E54214 recognition, and halogen-free RoHS-compliant M3 suffix packaging.

Technical Context

The GBU8K-M3/45 implements a standard full-wave bridge configuration with four silicon diodes arranged in a single-package in-line layout. Its glass passivation ensures stable reverse characteristics under humid or contaminated environments, while the GBU case supports direct heatsink mounting via #6 screws and silicone thermal compound.

Designed for PCB-level integration without discrete heatsinking in moderate-power applications, it delivers 8.0 A average rectified output with derating to 3.9 A at ambient (T_A = 40 °C) and maintains 1500 V_RMS dielectric strength between case and terminals - critical for safety isolation in Class II power supplies.

Key Specifications

Pinout & Package

Package: GBU case - molded plastic housing with matte tin-plated leads, UL 94 V-0 rated, 0.720" × 0.470" × 0.210" (18.3 mm × 12.0 mm × 5.3 mm), designed for bolt-down heatsink mounting or PCB through-hole soldering with 0.375" (9.5 mm) lead length.

Key Features

Applications

Equivalent & Alternatives

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

Compared with GBU8K-M3/45, GBU8K-E3/45 offers identical performance with standard RoHS compliance, while KBU8K trades minor electrical de-rating (1.1 V V_F, 175 A I_FSM) for alternate sourcing - neither is pin-compatible by default, but both share the same footprint and mounting geometry.

Availability

GBU8K-M3/45 is available at Aetrix Electronics and suitable for switching mode power supplies, printer adapters, and home appliance control boards requiring stable component supply, halogen-free compliance, and 800 V rectification capability.

Supply support for GBU8K-M3/45 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

Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, MOSFETs, and optoelectronics with emphasis on reliability and industrial-grade performance.

The GBU series was engineered for high-current, high-voltage AC/DC conversion in space-constrained consumer and industrial power supplies - prioritizing surge robustness, thermal efficiency, and regulatory compliance.

FAQ

What is the maximum junction temperature rating for GBU8K-M3/45?

The GBU8K-M3/45 has a specified operating junction temperature range of –55 °C to +150 °C. This 150 °C maximum enables reliable operation in enclosed power supplies with limited airflow, provided thermal design accounts for R_θJC = 4.0 °C/W and heatsink interface resistance. Derating curves in the Vishay datasheet (88616) define safe current limits at elevated temperatures.

Does GBU8K-M3/45 require a heatsink in all applications?

GBU8K-M3/45 does not require a heatsink in low-duty-cycle or low-ambient applications, but its 8.0 A I_F(AV) rating assumes case temperature (T_C) ≤ 60 °C - typically achieved only with aluminum plate heatsink mounting. In free-air PCB mounting (T_A = 40 °C), the rating drops to 3.9 A; thus, heatsinking is mandatory for sustained 8 A operation. The GBU package supports bolt-down mounting with #6 screws.

What does the "M3" suffix mean in GBU8K-M3/45?

The "M3" suffix in GBU8K-M3/45 indicates halogen-free, RoHS-compliant construction meeting JEDEC J-STD-020 and JESD 201 Class 1A whisker test requirements. Unlike the E3 variant, M3 uses bromine- and chlorine-free molding compounds and matte tin-plated leads - required for compliance with IEC 61249-2-21 and certain regional environmental mandates.

Can GBU8K-M3/45 be used in place of GBU8J-M3/45?

Yes, GBU8K-M3/45 can replace GBU8J-M3/45 in designs requiring higher reverse voltage tolerance: GBU8K-M3/45 has V_RRM = 800 V versus 600 V for GBU8J-M3/45. Both share identical package, pinout, thermal specs, and surge rating (200 A). No PCB changes are needed, but verify that downstream components (bulk capacitor, switcher FET) are rated for the higher DC bus voltage resulting from 800 V rectification.

What is the typical junction capacitance of GBU8K-M3/45?

The typical junction capacitance (C_J) of GBU8K-M3/45 is 68 pF per diode at 4 V and 1 MHz, as measured in the Vishay datasheet (88616, page 2). This value influences high-frequency noise coupling and EMI filter design - especially relevant in high-switching-frequency SMPS where rectifier capacitance interacts with transformer leakage inductance.