LTC3785

1

3785f

10V, High Efficiency,

Buck-Boost Controller

controller that drives all N-channel power MOSFETs from

input voltages above, below and equal to the output volt-

age. With an input range of 2.7V to 10V, the LTC3785 is

well suited for a wide variety of single or dual cell Li-Ion

or multi-cell alkaline/NiMH applications.

The operating frequency can be programmed from

100kHz to 1MHz. The soft-start time and current limit are

also programmable. The soft-start capacitor doubles as

the fault timer which can program the IC to latch off or

recycle after a determined off time. Burst Mode opera-

tion is user controlled and can be enabled by driving the

MODE pin high.

Protection features include foldback current limit, short-

circuit and overvoltage protection.

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Palmtop Computers

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Handheld Instruments

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Wireless Modems

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Cellular Telephones

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2.7V to 10V Input and Output Range

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Up to 96% Efficiency

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Up to 10A of Output Current

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True Output Disconnect During Shutdown

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Programmable Current Limit and Soft-Start

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Optional Short-Circuit Shutdown Timer

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Output Overvoltage and Undervoltage Protection

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Programmable Frequency: 100kHz to 1MHz

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Available in 24-Lead (4mm × 4mm) Exposed Pad

QFN Package

Efficiency vs Input Voltage

APPLICATIO S

FEATURES

DESCRIPTIO

TYPICAL APPLICATIO

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

All other trademarks are the property of their respective owners.

2.5

95

10

3785 TA01b

90

85

4

5.5

78.5

100

TG1

BG1

FB

TG2

BG2

SW2

3785 TA01a

SW1

RT

CCM

MODE

RUN/SS

LTC3785

GND

4.7

µF

2.7V

TO 10V

3.3V

5A

22

µF

4.7

µH

100

µF