The ISL6526, ISL6526A make 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 ISL6526,

ISL6526A integrate the control, output adjustment,

monitoring and protection functions into a single package.

The ISL6526, ISL6526A provide 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 6V/μs 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 rDS(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.

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

- ISL6526: 300kHz

- ISL6526A: 600kHz

• Internal Soft-Start

• 14 Ld SOIC or 16 Ld 5x5 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)

Applications

• Power Supplies for Microprocessors

- PCs

- Embedded Controllers

• Subsystem Power Supplies

- PCI/AGP/GTL+ Buses

- ACPI Power Control

- 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

• 3.3V-Input DC/DC Regulators

• Low-Voltage Distributed Power Supplies