Taiwan Semiconductor Corporation GBU804-K

Overview

GBU804-K from Taiwan Semiconductor is a 8A, 400V standard bridge rectifier in GBU package, featuring 200A surge current capability, 1500VRMS dielectric strength, and typical reverse leakage <5µA at 25°C. It serves as AC-to-DC front-end conversion in compact off-line power supplies.

For engineers reviewing the GBU804-K datasheet, GBU804-K pinout, GBU804-K application, or GBU804-K equivalent, key selection criteria include repetitive peak reverse voltage (400V), thermal resistance (R_θJA = 21°C/W), junction temperature range (–55°C to +150°C), and UL recognition (E-326243).

Technical Context

The GBU804-K integrates four silicon diodes in a single-phase full-wave bridge configuration with common-cathode and common-anode terminals. Its quad-diode layout enables direct AC input rectification without external interconnection.

Thermal design is supported by low junction-to-case resistance (2°C/W) and UL 94V-0 molding compound. Matte tin-plated leads ensure solderability per J-STD-002, and polarity is marked on the case for unambiguous orientation during PCB assembly.

Key Specifications

Pinout & Package

Package: GBU - molded plastic case with 4 axial leads, UL 94V-0 rated, 4.0g weight, maximum mounting torque 0.56 N·m.

Key Features

Applications

Equivalent & Alternatives

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

Compared with GBU8K and KBU8D, the GBU804-K offers superior thermal performance (R_θJA = 21°C/W) and tighter reverse leakage control (<5µA), making it optimal for space-constrained, thermally demanding, or low-standby-power applications.

Availability

GBU804-K is available at Aetrix Electronics and suitable for switching mode power supplies, AC-DC adapters, and LED lighting drivers requiring stable component supply across production lifecycles.

Supply support for GBU804-K 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

Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving global power electronics markets since 1979.

The GBU series was designed specifically for high-reliability, cost-optimized AC/DC front-end rectification in consumer, industrial, and lighting power supplies - emphasizing safety certification, thermal robustness, and manufacturability.

FAQ

What is the maximum operating junction temperature for GBU804-K?

The GBU804-K has a maximum junction temperature (T_J) of +150°C, with a storage temperature range of –55°C to +150°C. This rating allows reliable operation in enclosed, high-ambient environments such as LED driver housings or industrial control cabinets. Derating curves in the datasheet confirm 8A average current is maintainable up to 85°C case temperature. Thermal design must account for R_θJC = 2°C/W and R_θJA = 21°C/W to avoid exceeding the GBU804-K junction limit.

Does GBU804-K meet UL safety standards?

Yes, the GBU804-K is UL Recognized under File #E-326243, confirming compliance with UL 60747-4 for semiconductor devices. This certification covers dielectric strength (1500VRMS), flammability (UL 94V-0 molding compound), and construction integrity. UL recognition applies directly to the GBU804-K part number and supports end-product safety approvals without requiring additional component-level testing.

What is the forward voltage drop of GBU804-K at rated current?

The GBU804-K exhibits a typical forward voltage drop of 1.0V per diode at 4A and 25°C, rising to a maximum of 1.1V per diode at 8A and 25°C. Since the device contains four series-connected diodes in bridge configuration, total conduction loss is approximately 2.2V at full load. These values are measured under pulsed conditions (PW = 0.3ms) and reflect real-world conduction behavior in SMPS and adapter applications using the GBU804-K.

Is GBU804-K compatible with lead-free reflow soldering processes?

Yes, the GBU804-K features matte tin-plated leads qualified to J-STD-002 for solderability, supporting both leaded and lead-free reflow profiles. The package is rated for peak reflow temperatures up to 260°C per JEDEC J-STD-020, and its UL 94V-0 molding compound remains stable under standard Pb-free thermal cycles. No special pre-baking is required prior to assembly, and the GBU804-K maintains mechanical and electrical integrity after multiple reflow passes.

How does the junction capacitance of GBU804-K affect EMI performance?

The GBU804-K has a measured junction capacitance (C_J) of 211pF per diode at 1MHz and 4V reverse bias. This capacitance contributes to common-mode noise coupling at high-frequency switching edges, particularly in flyback and resonant converters. Designers should include Y-capacitors and common-mode chokes sized to suppress noise generated by the GBU804-K's inherent capacitance, especially when used in Class B EMI-compliant lighting or adapter designs.