LTC3125

1

3125fa

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

1.2A Synchronous Step-Up

DC/DC Converter with

Input Current Limit

The LTC

DC/DC converter with an accurate programmable average

input current limit. The resistor programmable average

input current limit is 5% accurate at 500mA and is suitable

for a wide variety of applications. In mobile computing,

GSM and GPRS cards demand high current pulses well

beyond the capability of the PC Card and CompactFlash

slots. The LTC3125 in concert with a reservoir capacitor,

keeps the slot power safely within its capabilities providing

a high performance and simple solution.

Synchronous rectification produces high efficiency while

the 1.6MHz switching frequency minimizes the solution

footprint. The current mode PWM design is internally com-

pensated. Output disconnect allows the load to discharge in

shutdown, while also providing inrush current limiting.

Other features include a <1μA shutdown current, short-

circuit and thermal overload protection. The LTC3125 is

offered in a low profile 0.75mm

× 2mm × 3mm package.

PCMCIA/CompactFlash (3.3V/500mA Max),

4V GSM Pulsed Load

× 3mm × 0.75mm DFN Package

L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

CS

2.2μH

LTC3125

GND

1.24M

2200μF

2

TANT

10μF

CER

4V

2A PULSED LOAD

3.3V

500mA

536k

3125 TA01a

SHDN

PROG

FB

44.2k

SW

OFF ON

Efficiency vs Load Current

LOAD CURRENT (A)

0.001

40

50

60

70

80

0.01

0.1

1

3125 TA01b

30

20

10

0

90

100

0.1

0.01

0.001

1