Diodes Incorporated KBJ3508

Overview

KBJ3508 from Diodes Incorporated is a 35A standard recovery bridge rectifier in KBJ package, rated for 800V repetitive peak reverse voltage (VRRM), 1.05V max forward voltage at 17.5A, and 10µA max reverse leakage at 25°C. It delivers reliable AC-to-DC conversion in high-current power supplies for consumer electronics.

For engineers reviewing the KBJ3508 datasheet, KBJ3508 pinout, KBJ3508 application, or KBJ3508 equivalent, key selection criteria include VRRM rating, thermal resistance (RθJA = 28°C/W without heatsink), derating behavior above 95°C case temperature, and UL recognition status (E95060).

Technical Context

This single-phase full-wave bridge rectifier uses glass-passivated silicon die to achieve stable conduction under continuous 35A average forward current with heatsink at TC = +95°C, or 3.5A without heatsink at TC = +125°C. Its 8.3ms non-repetitive surge rating of 380A supports inrush tolerance in switched-mode power supplies.

Thermal design relies on low junction-to-case resistance (RθJC = 5°C/W without heatsink; 1°C/W with cooler), while junction capacitance (165pF at 1MHz, 4V reverse) and reverse leakage (500µA at 125°C) define high-frequency and high-temperature performance boundaries.

Key Specifications

Pinout & Package

Package: KBJ - Molded plastic, "Green" UL 94V-0 compliant housing with matte tin-plated leads; weight ≈4.6g; mountable in any orientation.

Key Features

Applications

Availability

KBJ3508 is available at Aetrix Electronics and suitable for TV power, game console power, and desktop PC power supplies requiring stable component supply with consistent lead-time and traceable sourcing.

Supply support for KBJ3508 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and the Americas.

The KBJ series belongs to Diodes' standard recovery bridge rectifier product line, engineered for cost-sensitive, high-volume AC/DC power conversion applications where robustness and regulatory compliance are critical.

FAQ

What is the maximum average forward current for KBJ3508 without a heatsink?

KBJ3508 supports 3.5A average forward current without a heatsink at TC = +125°C, per the derating curve in DS45504 Rev. 4-2. This value drops significantly above 125°C case temperature and requires careful PCB copper area design to maintain thermal stability.

Is KBJ3508 suitable for automotive applications?

KBJ3508 is not AEC-Q101 qualified and lacks PPAP documentation or IATF 16949-specific change control. Diodes explicitly states that automotive-grade variants require direct consultation - this part is intended for industrial and consumer power supplies only.

How does the KBJ3508 package differ from KBPC or GBU packages?

KBJ has a rectangular, insulated plastic body with four axial leads in inline configuration (AC1–AC2–+––), unlike KBPC's square body or GBU's larger footprint. Its 4.6g weight and UL 94V-0 rating reflect optimized PCB-mount reliability for mid-power applications.

What is the typical junction capacitance and its impact on EMI?

KBJ3508 exhibits 165pF typical junction capacitance at 1MHz and 4V reverse bias. This value influences high-frequency reverse recovery noise and must be considered in EMI filter design, especially in high-switching-frequency SMPS where di/dt is significant.