Single Sync Buck PWM Controller for Broadband Gateway Applications

The ISL6439 makes easy work out of implementing a complete control and protection scheme for a DC-DC stepdown converter. Designed to drive N-Channel MOSFETs in a synchronous buck topology, the ISL6439 integrates the control, output adjustment, monitoring and protection functions into a single package.

Features
• Operates from 3.3V to 5V Input
• 0.8V to VIN Output Range
    - 0.8V Internal Reference
    - ±1.5% Over Load, Line Voltage and Temperature
• Drives N-Channel MOSFETs
• Simple Single-Loop Control Design
    - Voltage-Mode PWM Control
• Fast Transient Response
    - High-Bandwidth Error Amplifier
    - Full 0% to 100% Duty Cycle
• Lossless, Programmable Overcurrent Protection
    - Uses Upper MOSFET’s rDS(on)
• Converter can Source and Sink Current
• Small Converter Size
    - Internal Fixed Frequency Oscillator
        - ISL6439: 300kHz
        - ISL6439A: 600kHz
• Internal Soft-Start
• 14 Pin SOIC or 16 Lead 5x5 QFN
• QFN Package:
    - Compliant to JEDEC PUB95 MO-220 QFN - Quad Flat
        No Lead - Package Outline
    - Near Chip Scale Package footprint, which improves
        PCB efficiency and has a thinner profile
• Pb-free available

Applications
• Cable Modems, Set Top Boxes, and DSL Modems
• DSP and Core Communications Processor Supplies
• Memory Supplies
• Personal Computer Peripherals
• Industrial Power Supplies
• 3.3V-Input DC-DC Regulators
• Low-Voltage Distributed Power Supplies