LTC3533

1

3533f

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

2A Wide Input Voltage

Synchronous Buck-Boost

DC/DC Converter

frequency, buck-boost DC/DC converter that operates

from input voltages above, below or equal to the output

voltage. The topology incorporated in the IC provides a

continuous transfer function through all operating modes,

making the product ideal for single cell lithium-ion/polymer

or multi-cell alkaline/NiMH applications where the output

voltage is within the input voltage range.

The LTC3533 features programmable Burst Mode opera-

increased output current. Switching frequencies up to

2MHz are programmed with an external resistor. The Burst

Mode threshold is programmed with a single resistor from

the BURST pin to GND.

Other features include 1µA shutdown current, short

circuit protection, programmable soft-start, current limit

and thermal shutdown. The LTC3533 is housed in the

thermally enhanced 14-lead (3mm

× 4mm × 0.75mm)

DFN package.

Efficiency

Below or Equal to the Output

Voltage Range

× 4mm ×

0.75mm) DFN package

SW1

RUN/SS

SW2

FB

LTC3533

10

µF

2.4V TO 4.2V

340k

6.49k

100

µF

47pF

3.3V

1.5A

200k

0.1

µF

107k

330pF

4.7pF

3533 TA01

2.2

µH

33.2k

200k

PGND

SGND

ON

OFF

BURST

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

Corporation. All other trademarks are the property of their respective owners.

OUTPUT CURRENT (mA)

0.1

40

50

60

70

80

1

10

100

1000

10000

3533 TA01b

30

20

10

0

90

100

Burst Mode

OPERATION