Taiwan Semiconductor Corporation KBU603G

Overview

KBU603G from Taiwan Semiconductor is a 6A, 200V repetitive peak reverse voltage (VRRM) glass-passivated quad-configuration standard bridge rectifier, rated for 175A non-repetitive surge current and operating up to 150°C junction temperature, used in AC/DC front-end conversion of switching mode power supplies.

For engineers reviewing the KBU603G datasheet, KBU603G pinout, KBU603G application, or KBU603G equivalent, key selection criteria include VRRM = 200V, IF = 6A, IFSM = 175A, RθJC = 3.1°C/W, and UL recognition per file E-326243 - all critical for thermal reliability and safety compliance in compact adapter and lighting designs.

Technical Context

The KBU603G integrates four silicon diodes in a single-phase full-wave bridge configuration with glass-passivated junctions, enabling high surge immunity and low leakage (IR ≤ 5 µA at 25°C). Its KBU package features matte tin-plated leads compliant with J-STD-002 solderability and JESD201 Class 1A whisker resistance.

Thermally, it delivers RθJA = 8.6°C/W (free-air) and RθJC = 3.1°C/W, supporting PCB-mounted operation without forced airflow in space-constrained adapters. Polarity is marked on the case, and mounting torque must not exceed 0.56 N·m to avoid mechanical damage.

Key Specifications

Pinout & Package

Package: KBU - Molded plastic case with 4 axial leads (AC1, AC2, +, –), UL 94V-0 rated, 7.2 g weight, polarity marked on top surface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with GBU6K and W04M, the KBU603G uniquely balances 200V VRRM, 6A rating, UL recognition, and 3.1°C/W thermal resistance - making it optimal for certified, thermally demanding 60–100W adapter and SMPS designs where safety and thermal headroom are co-prioritized.

Availability

KBU603G is available at Aetrix Electronics and suitable for switching mode power supplies, AC/DC adapters, and LED lighting drivers requiring stable component supply, long-lifecycle availability, and traceable sourcing.

Supply support for KBU603G 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, industrial, and consumer markets since 1979.

The KBU603G belongs to TSC's standard bridge rectifier product line, engineered for high-reliability AC/DC conversion in cost-sensitive, safety-certified power supplies where thermal robustness and long-term parametric stability are essential.

FAQ

What is the maximum repetitive peak reverse voltage (VRRM) for KBU603G?

The KBU603G has a VRRM of 200 V, meaning it reliably blocks up to 200 volts of reverse voltage across its terminals in continuous operation. This value is laser-marked as "603" on the device body and is validated per Taiwan Semiconductor's J2103 specification sheet. Designers must ensure input AC peak voltage remains below this rating with appropriate safety margin - e.g., 200V VRRM supports 100VAC nominal input (141V peak) with ~40% margin.

Does KBU603G require a heatsink in typical 6A operation?

KBU603G can operate at 6A average forward current without an external heatsink when ambient temperature stays ≤ 55°C and PCB copper area is ≥ 4 cm² per lead, thanks to its RθJC = 3.1°C/W and RθJA = 8.6°C/W. However, at 70°C ambient or sustained 6A load, a small clip-on heatsink or thermal pad to chassis improves reliability. The KBU603G datasheet provides derating curves confirming 6A is sustainable up to 75°C ambient with adequate board copper.

Is KBU603G RoHS compliant and halogen-free?

Yes, KBU603G is RoHS compliant per EU Directive 2011/65/EU, with lead content < 1000 ppm and restricted substances within limits. Taiwan Semiconductor confirms halogen-free status (Br < 900 ppm, Cl < 900 ppm, total halogens < 1500 ppm) in its material declaration for KBU603G. This compliance is documented in TSC's official product change notices and applies to all units shipped after Version J2103.

What is the marking code on the KBU603G case?

The KBU603G is marked with "KBU603G" on the top surface of the KBU package, followed by a date code (e.g., "2325" for week 25 of 2023) and factory code. The "603" segment explicitly identifies the 200V VRRM variant within the KBU601G–KBU607G family. No additional suffixes or revisions appear on standard production units per J2103 version control.

Can KBU603G replace KBU602G in an existing design?

Yes, KBU603G is a direct upgrade from KBU602G (100V VRRM) with identical package, pinout, thermal performance, and electrical characteristics except for higher VRRM (200V vs. 100V). No PCB or layout changes are needed. Designers should verify that the increased blocking voltage does not affect snubber or clamping network sizing - though in most SMPS front-ends, the higher rating adds margin without circuit modification.