LTC3124

1

3124f

TYPICAL APPLICATION

FEATURES

DESCRIPTION

15V, 5A 2-Phase Synchronous

Step-Up DC/DC Converter with

Output Disconnect

The LTC®3124 is a dual-phase, synchronous step-up DC/

DC converter with true output disconnect and inrush

current limiting capable of providing output voltages up

to 15V. Dual-phase operation significantly reduces peak

inductor and capacitor ripple currents, minimizing induc-

tor and capacitor size. The 2.5A per phase current limit,

along with the ability to program output voltages up to 15V

make the LTC3124 well suited for a variety of demanding

applications. Once started, operation will continue with

inputs down to 500mV.

The LTC3124 switching frequency can be programmed

from 100kHz to 3MHz to optimize applications for highest

efficiency or smallest solution footprint. The oscillator can

be synchronized to an external clock for noise sensitive

applications. Selectable Burst Mode operation reduces

quiescent current to 25µA, ensuring high efficiency across

the entire load range. An internal soft-start limits inrush

current during start-up.

Otherfeaturesincludea<1µAshutdowncurrentandrobust

protectionundershort-circuit,thermaloverload,andoutput

overvoltage conditions. The LTC3124 is offered in both

16-lead DFN and thermally-enhanced TSSOP packages.

5V to 12V Synchronous Boost Converter

Efficiency Curve

APPLICATIONS

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Adjustable Output Voltage: 2.5V to 15V

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Dual-Phase Control Reduces Output Voltage Ripple

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Output Disconnects from Input When Shut Down

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Synchronous Rectification: Up to 95% Efficiency

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Inrush Current Limit

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Up to 3MHz Programmable Switching Frequency

Synchronizable to External Clock

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Output Overvoltage Protection

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Internal Soft-Start

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16-Lead, Thermally- Enhanced 3mm

× 5mm ×

0.75mm DFN and TSSOP Packages

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RF, Microwave Power Amplifiers

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Piezo Actuators

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Small DC Motors, Thermal Printers

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12V Analog Rail from Battery, 5V, or Backup Capacitor

L

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

and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the

property of their respective owners.

100nF

12V

1.5A

22µF

×2

4.7µH

4.7µH

5V

SWB

CAP

PGNDB

SWA

LTC3124

680pF

56pF

3124 TA01a

4.7µF

10µF

1.02M

113k

84.5k

28k

OFF ON

SGND

PWM/SYNC

SD

FB

RT

PGNDA

BURST PWM

100

10

90

70

50

30

80

60

40

20

0

10

1

0.1

0.01

0.001

0.0001

LOAD CURRENT (mA)

3124 TA01b

0.01

1000

100

PWM

PWM

10

0.1

1

Burst Mode

OPERATION

Burst Mode

OPERATION

EFFICIENCY

POWER LOSS