LTC3443

1

sn3443 3443fs

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

to the Output

Lithium-Ion

(4mm × 3mm × 0.8mm) DFN package

High Current Micropower

600kHz Synchronous Buck-Boost

DC/DC Converter

The LTC

boost DC/DC converter that operates from input voltages

above, below or equal to the output voltage. The part is pin

for pin compatible with its predecessor, the LTC3441, with

circuit during Burst Mode operation. The topology incor-

porated in the IC provides a continuous transfer function

through all operating modes, making the product ideal for

single Lithium Ion or multicell applications where the out-

put voltage is within the battery voltage range.

The device includes two 0.10Ω N-channel MOSFET

switches and two 0.11Ω P-channel switches. External

Schottky diodes are optional, and can be used for a

moderate efficiency improvement. The operating frequency

is internally set to 600kHz and can be synchronized up to

1.2MHz. Quiescent current is only 28µA 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 1µA shutdown, soft-start control,

thermal shutdown and current limit. The LTC3443 is

available in a thermally enhanced 12-lead (4mm × 3mm)

DFN Package.

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

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

SW1

SHDN/SS

MODE/SYNC

PGND

SW2

FB

GND

PGND

LTC3443

10µF

2.5V

TO 4.2V

Li-Ion

15k

340k

44µF

(2 × 22µF)

3.3V

1A

200k

560pF

3443 TA01

6µH

2.2k

220pF

2.7

50

60

70

80

3.2

3.7

4.2

4.7

3443 TA02

90

100

55

65

75

85

95

5.2

Burst Mode is a registered trademark of Linear Technology Corporation.

U.S. Patent #’s 6404251, 6166527