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