LTC3532

1

3532fc

Micropower Synchronous

Buck-Boost DC/DC Converter

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 lithium-ion, multicell alkaline or NiMH ap-

plications where the output voltage is within the battery

voltage range.

The device includes two 0.36Ω N-channel MOSFET

switches and two 0.42Ω P-channel switches. Switching

frequencies up to 2MHz are programmed with an external

resistor. Quiescent current is only 35μA in Burst Mode

operation, maximizing battery life in portable applica-

tions. Automatic Burst Mode operation allows the user

to program the load current for Burst Mode operation or

to control it manually.

Other features include a 1μA shutdown, soft-start control,

thermal shutdown, and peak current limit. The LTC3532 is

available in a low profile (0.75mm) 10-lead (3mm × 3mm)

DFN and 10-lead MSOP packages.

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Miniature Hard Disk Drive Power Supply

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MP3 Players

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Handheld Instruments

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Digital Cameras

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Handheld Terminals

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Single Inductor

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Regulated Output with Input Voltages Above, Below

or Equal to the Output

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Up to 500mA Peak Output Current

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Synchronous Rectification: Up to 95% Efficiency

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Operation

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Output Disconnect in Shutdown

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Programmable Oscillator: 300kHz to 2MHz

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Pin Compatible with LTC3440

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Small Thermally Enhanced 10-Lead (3mm × 3mm)

DFN and 10-Lead MSOP Packages

Miniature Hard Disk Drive Power Supply

APPLICATIO S

FEATURES

DESCRIPTIO

TYPICAL APPLICATIO

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

Burst Mode is a registered trademark of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

SW1

SHDN/SS

BURST

SW2

FB

GND

LTC3532

3532 TA01

43.2k

0.01μF

200k

4.7μF

Li-Ion

2.5V TO 4.2V

4.7μH

3.3V

100mA

TO 500mA

(PEAK)

10μF

33pF

1k

340k

12.1k

220pF

200k

200mV/DIV

100mA/DIV

100μs/DIV

3532 TA01b