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Dual 800mA Low Quiescent Current 2.25MHz High

Efficiency Synchronous Buck Regulator

ISL8088

The ISL8088 is a high efficiency, dual synchronous

step-down DC/DC regulator that can deliver up to 800mA

continuous output current per channel. The supply

voltage range of 2.75V to 5.5V allows the use of a single

Li+ cell, three NiMH cells or a regulated 5V input. The

current mode control architecture enables very low duty

cycle operation at high frequency with fast transient

response and excellent loop stability. The ISL8088

operates at 2.25MHz switching frequency allowing the

use of small, low cost inductors and capacitors. Each

channel is optimized for generating an output voltage as

low as 0.6V.

The ISL8088 has a user configurable mode of

operation-forced PWM mode and PFM/PWM mode. The

forced PWM mode operation reduces noise and RF

interference while the PFM mode operation provides high

efficiency by reducing switching losses at light loads. In

PFM mode of operation, both channels draw a total

quiescent current of only 30µA hence enabling high light

load efficiency in order to maximize battery life.

The ISL8088 offers a 1ms Power-Good (PG) to monitor

both output at power-up. When shutdown, ISL8088

discharges the outputs capacitor. Other features include

internal digital soft-start, enable for power sequence,

overcurrent protection, and thermal shutdown. The

ISL8088 is offered in a 3mmx3mm 10 Ld DFN package

with 1mm maximum height. The complete converter

Features

• Internal Current Mode Compensation

• 100% Maximum Duty Cycle for Lowest Dropout

• Selectable Forced PWM Mode and PFM Mode

• External Synchronization up to 4MHz

• Start-up with Pre-biased Output

• Soft-Stop Output Discharge During Disabled

• Internal Digital Soft-Start - 2ms

• Power-Good (PG) Output with 1ms Delay

• DC/DC POL Modules

•µC/µP, FPGA and DSP Power

• Plug-in DC/DC Modules for Routers and Switchers

• Test and Measurement Systems

• Li-ion Battery Power Devices

• Bar Code Readers

Efficiency Characteristics Curve

OUTPUT LOAD (A)

40

50

60

70

80

90

100

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

VIN = 5V

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 1-888-468-3774

Copyright Intersil Americas Inc. 2009, 2010. All Rights Reserved

All other trademarks mentioned are the property of their respective owners.

April 29, 2010

FN6858.1