AAT1153

2A Step-Down Converter

PRODUCT DATASHEET

1153.2008.02.1.2

1

www .analogictech.com

General Description

The AAT1153 SwitchReg™ is a 1.2MHz constant fre-

quency current mode PWM step-down converter. It is

ideal for portable equipment requiring very high current

up to 2A from single-cell Lithium-ion batteries while still

achieving over 90% efficiency during peak load condi-

tions. The AAT1153 also can run at 100% duty cycle for

low dropout operation, extending battery life in portable

systems while light load operation provides very low

output ripple for noise sensitive applications.

The AAT1153 can supply up to 2A output load current

from a 2.5V to 5.5V input voltage and the output voltage

can be regulated as low as 0.6V. The high switching fre-

quency minimizes the size of external components while

keeping switching losses low. The internal slope compen-

sation setting allows the device to operate with smaller

inductor values to optimize size and provide efficient

operation.

fixed (1.8V) output voltage versions. The device is avail-

able in a Pb-free, 3mm x 3mm 10-lead TDFN package and

is rated over the -40°C to +85°C temperature range.

Features

• Input Voltage Range: 2.5V to 5.5V

• 2A Output Current

• High Efficiency: Up to 95%

• 1.2MHz Constant Switching Frequency

• Allows Use of Ceramic Capacitors

• Current Mode Operation for Excellent Line and Load

Transient Response

• Short-Circuit and Thermal Fault Protection

• Soft Start

• Low Dropout Operation: 100% Duty Cycle

• TDFN33-10 Package

• -40°C to +85°C Temperature Range

Applications

• Cellular Phones

• Digital Cameras

• DSP Core Supplies

• PDAs

• Portable Instruments

• Smart Phones

Typical Application

PGND

PGND

LX

LX

EN

IN

AIN

AGND

OUT

AAT1153-1.8

C1

22μF

V

L1

2.2μH

C2

22μF

V

OUT

1.8V, 2A

1

2

3

4

5

7

8

9

10

AGND

6