ISL6520A
Single Synchronous Buck Pulse-Width Modulation (PWM) controller

Key Features

• Operates from +5V Input
• 0.8V to V_IN Output Range
• 0.8V Internal Reference
• ±1.5% Over 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 r_DS(ON)
• Small Converter Size
• 300kHz Fixed Frequency Oscillator
• Internal Soft-Start
• 8 Ld SOIC or 16 Ld 4mmx4mm QFN
• QFN Package:
• Compliant to JEDEC PUB95 MO-220 QFN - Quad Flat No Leads - Package Outline
• Near Chip Scale Package footprint, which improves PCB efficiency and has a thinner profile
• Pb-Free (RoHS Compliant)

Description

The ISL6520A makes simple 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 ISL6520A integrates the control, output adjustment, monitoring and protection functions into a single 8 Lead package.

The ISL6520A provides simple, single feedback loop, voltage-mode control with fast transient response. The output voltage can be precisely regulated to as low as 0.8V, with a maximum tolerance of ±1.5% over-temperature and line voltage variations. A fixed frequency oscillator reduces design complexity, while balancing typical application cost and efficiency.

The error amplifier features a 15MHz gain-bandwidth product and 8V/ms slew rate which enables high converter bandwidth for fast transient performance. The resulting PWM duty cycles range from 0% to 100%.

Protection from overcurrent conditions is provided by monitoring the r_DS(ON) of the upper MOSFET to inhibit PWM operation appropriately. This approach simplifies the implementation and improves efficiency by eliminating the need for a current sense resistor.

Applications

• Power Supplies for Microprocessors
• PCs
• Embedded Controllers
• Subsystem Power Supplies
• PCI/AGP/GTL+ Buses
• ACPI Power Control
• SSTL-2 and DDR SDRAM Bus Termination Supply
• Cable Modems, Set Top Boxes, and DSL Modems
• DSP and Core Communications Processor Supplies
• Memory Supplies
• Personal Computer Peripherals
• Industrial Power Supplies
• 5V-Input DC/DC Regulators
• Low-Voltage Distributed Power Supplies