Taiwan Semiconductor Corporation KBL401G

Overview

KBL401G from Taiwan Semiconductor is a 4A, 50V repetitive peak reverse voltage (V_RRM) glass-passivated standard bridge rectifier in KBL package, featuring 150A peak forward surge current (I_FSM), 2.4°C/W junction-to-lead thermal resistance, and UL Recognized File # E-326243 - used in compact AC/DC front-end stages of low-voltage switching mode power supplies.

For engineers reviewing the KBL401G datasheet, KBL401G pinout, KBL401G application, or KBL401G equivalent, key selection criteria include V_RRM=50V rating, I_F=4A average forward current, thermal performance (R_θJL=2.4°C/W), RoHS compliance, and KBL package mechanical compatibility with PCB-mount SMPS designs.

Technical Context

The KBL401G integrates four silicon diodes in a single-phase full-wave bridge configuration with glass-passivated junctions for enhanced moisture and contamination resistance. Its KBL molded plastic case meets UL 94V-0 flammability rating and supports matte tin-plated leads compliant with J-STD-002 solderability and JESD 201 Class 1A whisker testing.

Thermally, it delivers R_θJL = 2.4°C/W and R_θJA = 19°C/W, enabling reliable operation up to T_J = +150°C. Electrical behavior includes V_F ≤ 1.1V at I_F = 4A and I_R ≤ 10µA at 25°C under rated reverse voltage - critical for low-loss, high-efficiency rectification in 50–60Hz line-fed converters.

Key Specifications

Pinout & Package

Package: KBL - 4-pin single-in-line (SIP) molded plastic body, 19.5 mm × 15.2 mm × 19.0 mm height, with matte tin-plated leads spaced 5.5 mm apart (center-to-center), UL 94V-0 rated, weight ≈5.6 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with GBU4A and DB101, the KBL401G provides superior thermal performance (R_θJL=2.4°C/W), UL recognition for safety-critical designs, and optimized KBL footprint for high-density SMPS layouts - making it the preferred choice for production-grade 4A, 50V bridge applications.

Availability

KBL401G is available at Aetrix Electronics and suitable for switching mode power supplies, USB wall adapters, and LED lighting applications requiring stable component supply, UL-compliant sourcing, and long-term industrial availability.

Supply support for KBL401G 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, specializing in rectifiers, TVS diodes, MOSFETs, and power ICs since 1979.

The KBL401G belongs to TSC's standard bridge rectifier product line, engineered for cost-effective, high-reliability AC/DC conversion in consumer, industrial, and lighting power supplies - emphasizing UL recognition, thermal robustness, and RoHS-compliant manufacturing.

FAQ

What is the maximum repetitive peak reverse voltage (V_RRM) rating for the KBL401G?

The KBL401G has a V_RRM rating of 50 V, as confirmed in the Absolute Maximum Ratings table of the official Taiwan Semiconductor datasheet (Version J2308). This value is specific to the KBL401G variant and distinguishes it from higher-voltage members of the KBL40xG family such as KBL402G (100V) and KBL407G (1000V). Designers must ensure input AC peak voltage remains below this threshold to prevent reverse breakdown.

Does the KBL401G have UL recognition, and what is the file number?

Yes, the KBL401G is UL Recognized with File # E-326243, explicitly stated in the FEATURES section of the Taiwan Semiconductor datasheet. This recognition applies to the entire KBL401G–KBL407G series and validates compliance with UL 60950-1/62368-1 for use in end-equipment safety certification - eliminating need for additional component-level UL testing when used per datasheet conditions.

What is the forward voltage (V_F) of the KBL401G at its rated 4A current?

At I_F = 4A and T_J = 25°C, the KBL401G exhibits a maximum forward voltage of 1.1 V per diode path, as specified in the ELECTRICAL SPECIFICATIONS table. This value is measured under pulsed conditions (PW = 0.3ms) and directly impacts conduction losses - for example, resulting in ~4.4W total dissipation across all four diodes at full load.

Is the KBL401G RoHS compliant, and does it meet lead-free soldering standards?

Yes, the KBL401G is RoHS compliant and features matte tin-plated leads qualified per J-STD-002 for solderability. The datasheet confirms compliance with RoHS Directive 2011/65/EU and specifies that terminals withstand standard lead-free reflow profiles (peak 260°C), supporting both Pb-free and SnPb assembly processes without degradation of solder joint integrity or whisker resistance.

What is the junction-to-lead thermal resistance (R_θJL) of the KBL401G, and why does it matter?

The KBL401G has a typical R_θJL of 2.4°C/W, meaning each watt of power dissipated raises the junction temperature 2.4°C above the lead temperature. This low value enables effective heat transfer to PCB copper pours or external heatsinks - critical for maintaining T_J ≤ 150°C in enclosed adapters or LED drivers where ambient temperatures exceed 60°C.