LTC3441

1

3441fa

to the Output

Lithium-Ion

μA Quiescent Current in Shutdown

× 3mm)

DFN package

High Current Micropower

Synchronous Buck-Boost

DC/DC Converter

Burst Mode is a registered trademark of Linear Technology Corporation.

The LTC

boost DC/DC converter that operates efficiently from input

voltages above, below or equal to the output voltage. The

topology incorporated in the IC provides a continuous trans-

fer function through all operating modes, making the prod-

uct ideal for single lithium ion or multicell applications where

the output voltage is within the battery voltage range.

The device includes two 0.10

Ω N-channel MOSFET

switches and two 0.11

Ω P-channel switches. External

Schottky diodes are optional, and can be used for a

moderate efficiency improvement. The operating frequency

is internally set to 1MHz and can be synchronized up to

1.7MHz. Quiescent current is only 25

μA in Burst Mode

operation, maximizing battery life in portable applications.

Burst Mode operation is user controlled and can be

enabled by driving the MODE/SYNC pin high. If the MODE/

SYNC pin is driven low or with a clock, then fixed fre-

quency switching is enabled.

Other features include a 1

μA shutdown, soft-start control,

thermal shutdown and current limit. The LTC3441 is

available in a thermally enhanced 12-lead (4mm

× 3mm)

DFN package.

2.5

50

60

70

80

3

3.5

4

4.5

3441 TA02

5

90

100

55

65

75

85

95

5.5

SW1

SHDN/SS

MODE/SYNC

PGND

5

8

12

11

2

6

4

9

10

1

7

3

SW2

FB

GND

PGND

LTC3441

10

μF

*1 = Burst Mode OPERATION

0 = FIXED FREQUENCY

L1: TOKO A916CY-4R7M

2.5V TO 4.2V

Li-Ion

*

15k

340k

22

μF

3.3V

1A

200k

1.5nF

3441 TA01

L1

4.7

μH

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

Li-Ion to 3.3V at 1A Buck-Boost Converter

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