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a

ADP3088

1 MHz, 750 mA Buck Regulator

FEATURES

1 MHz PWM Frequency

Automatic PWM to Power Saving Mode at Light Load

Fully Integrated 1 A Power Switch

3% Output Regulation Accuracy over Temperature,

Line, and Load

100% Duty Cycle Operation

Simple Compensation

Output Voltage: 1.25 V to 10.5 V

Small Inductor and MLC Capacitors

Low Quiescent Current while Pulse Skipping

Thermal Shutdown

Fully Integrated Soft Start

Cycle-by-Cycle Current Limit

APPLICATIONS

PDAs and Palmtop Computers

Notebook Computers

PCMCIA Cards

Bus Products

Portable Instruments

FUNCTIONAL BLOCK DIAGRAM

SW

FB

COMP

GND

IN

DRV

CURRENT

SENSE

AMP

PWM

COMPARATOR

REF

1.245V

ERROR

AMP

SOFT START

TIMER

+

R

S

Q

RUN/STOP

COMPARATORS

1MHz

PROTECTION

LOGIC

(ILIM, OT)

IN

GND

ADP3088

GENERAL DESCRIPTION

The ADP3088 is a high frequency, nonsynchronous PWM step-

down dc-to-dc regulator with an integrated 1 A power switch

in a space-saving MSOP-8 package. It provides high efficiency

and excellent dynamic response and is very simple to use.

The ADP3088’s 1 MHz switching frequency allows for small,

inexpensive external components, and the current mode control

loop is simple to compensate and eases noise filtering. The device

operates in PWM current mode under heavy loads and saves

energy at lighter loads by switching automatically into power

saving mode. Soft start is integrated completely on-chip, as is

the cycle-by-cycle current limit.

Capable of operating from 2.5 V to 11 V input, the ADP3088 is

ideal for many applications, including portable, battery-powered

applications where local point-of-use power regulation is

required. Supporting output voltages down to 1.25 V, the

ADP3088 is ideal for generating low voltage rails, providing

the optimal solution in its class for delivering power efficiently,

responsively, and simply with a minimal printed circuit board area.

The device is specified over the industrial temperature range of

–40

∞C to +85∞C.

SW

DRV

FB

IN

GND

COMP

ADP3088

1.8V

3.3 H

10.0k

22.4k

20k

4.7pF

1N5817

IN

GND

10 F

0.1 F

220pF

3.3V

10 F

Figure 1. Typical Application