Taiwan Semiconductor Corporation KBL404G

Overview

KBL404G from Taiwan Semiconductor is a 4A, 400V repetitive peak reverse voltage (V_RRM) standard bridge rectifier in KBL package, featuring glass-passivated junctions, UL Recognized (E-326243), RoHS-compliant construction, and 150A peak surge capability - used in AC/DC front-end stages of compact switching mode power supplies.

For engineers reviewing the KBL404G datasheet, KBL404G pinout, KBL404G application, or KBL404G equivalent, key selection criteria include V_RRM = 400 V, I_F = 4 A, V_F ≤ 1.1 V @ 4 A, R_θJA = 19 °C/W, and KBL package thermal/mechanical compatibility with PCB-mount SMPS designs.

Technical Context

The KBL404G integrates four silicon diodes in a single-phase full-wave bridge configuration with common-cathode and common-anode terminals. Its glass-passivated junction ensures stable reverse leakage (<500 µA @ 125°C) and robust surge handling (I_FSM = 150 A, 8.3 ms).

Thermally, it delivers R_θJL = 2.4 °C/W to lead and R_θJA = 19 °C/W to ambient, enabling operation up to T_J = 150°C. The KBL molded plastic case meets UL 94V-0 and JESD201 Class 1A whisker resistance.

Key Specifications

Pinout & Package

Package: KBL - 4-pin single-in-line (SIL) molded plastic body, 19.5 mm × 15.2 mm × 19.0 mm height, matte tin-plated leads, UL 94V-0 rated compound, weight ≈5.6 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with GBU4K, KBL404G offers lower R_θJA (19 vs. 25 °C/W) and higher surge robustness (150 vs. 120 A); versus DB104, KBL404G delivers 4× higher continuous current and 3× higher surge capacity - making it the sole viable option for 4 A SMPS front-ends.

Availability

KBL404G is available at Aetrix Electronics and suitable for switching mode power supplies, AC/DC adapters, and LED lighting drivers requiring stable component supply with UL recognition and industrial temperature range support.

Supply support for KBL404G 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 KBL series was developed specifically for cost-sensitive, high-volume AC/DC rectification applications demanding UL recognition, RoHS compliance, and reliable thermal performance in compact KBL packaging.

FAQ

What is the maximum repetitive peak reverse voltage (V_RRM) for KBL404G?

The KBL404G has a V_RRM of 400 V, confirmed in the Absolute Maximum Ratings table across all versions of the KBL401G–KBL407G datasheet. This rating applies directly to KBL404G and defines its ability to block reverse voltage during the non-conducting half-cycle of AC input. Exceeding 400 V risks avalanche breakdown and permanent damage to the KBL404G.

Does KBL404G support lead-free soldering processes?

Yes, the KBL404G features matte tin-plated leads qualified per J-STD-002 for solderability, and its package withstands peak reflow temperatures up to 260°C - fully compatible with standard lead-free soldering profiles. The KBL404G's UL 94V-0 molding compound also remains stable under these thermal conditions without delamination or charring.

What is the forward voltage drop (V_F) of KBL404G at rated current?

The KBL404G exhibits a maximum forward voltage of 1.1 V at I_F = 4 A and T_J = 25°C, as specified in the Electrical Specifications table. This value represents worst-case conduction loss per device; actual V_F decreases at lower currents and increases slightly at elevated junction temperatures - critical for calculating thermal design margins in the KBL404G application.

Is KBL404G UL Recognized, and what is the file number?

Yes, the KBL404G is UL Recognized under File # E-326243, explicitly stated in the FEATURES section of the official Taiwan Semiconductor datasheet. This recognition covers the entire KBL401G–KBL407G family and validates compliance with UL 60747-4 for discrete semiconductors, supporting end-product safety certifications without additional component-level testing.

What is the junction-to-ambient thermal resistance (R_θJA) of KBL404G?

The KBL404G has an R_θJA of 19 °C/W, measured under standard JEDEC test conditions (single-layer 1 in² copper pad, no airflow). This parameter determines how much the junction temperature rises above ambient at a given power dissipation - for example, at 4 A and V_F = 1.1 V, power dissipation is ~4.4 W, resulting in ΔT = 84°C above ambient, requiring careful PCB layout to keep T_J ≤ 150°C in the KBL404G design.