LTC3370

1

3370fb

For more information www.linear.com/LTC3370

Typical applicaTion

FeaTures

DescripTion

4-Channel 8A Configurable

Buck DC/DCs

The LTC®3370 is a highly flexible multioutput power

supply IC. The device includes four synchronous buck

converters, configured to share eight 1A power stages,

each of which is powered from independent 2.25V to

5.5V inputs.

The DC/DCs are assigned to one of eight power configu-

rations via pin programmable C1-C3 pins. The common

buck switching frequency may be programmed with an

external resistor, synchronized to an external oscillator,

or set to a default internal 2MHz clock.

The operating mode for all DC/DCs may be programmed

viathePLL/MODEpinforBurstModeorforcedcontinuous

mode operation. A PGOODALL output indicates when all

enabled DC/DCs are within a specified percentage of their

final output value.

To reduce input noise, the buck converters are phased

in 90° steps. Precision enable pin thresholds facilitate

reliable power-up sequencing. The LTC3370 is available

in a 32-lead 5mm × 5mm QFN package.

applicaTions

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8 × 1A Power Stages Configurable as 2, 3, or 4 Output

Channels

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8 Unique Output Configurations (1A to 4A Per Channel)

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(2.25V to 5.5V)

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Low Total No Load Supply Current:

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Zero Current In Shutdown (All Channels Off)

n

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18µA Per Additional Channel

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Precision Enable Pin Thresholds for Autonomous

Sequencing

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1MHz to 3MHz RT Programmable Frequency

(2MHz Default) or PLL Synchronization

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Temp Monitor Indicates Die Temperature

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PGOODALL Pin Indicates All Enabled Bucks Are in

Regulation

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32-Lead 5mm × 5mm QFN Package

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General Purpose Multichannel Power Supplies:

Automotive, Industrial, Distributed Power Systems

L

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

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

C3

C2

C1

BUCK1 BUCK2 BUCK3 BUCK4

0

0

0

0

1

1

1

1

0

0

1

1

0

0

1

1

0

1

0

1

0

1

0

1

2A

3A

3A

4A

3A

4A

4A

4A

2A

1A

1A

1A

2A

–

–

–

2A

2A

1A

1A

–

2A

1A

–

2A

2A

3A

2A

3A

2A

3A

4A

2.25V TO 5.5V

SWA

SWB

SWE

SWF

2.25V TO 5.5V

1.2V/2A

1.8V/2A

2.5V/2A

1.5V/2A

324k

649k

402k

715k

649k

806k

649k

665k

309k

2.7V TO 5.5V

LTC3370

C1 C2 C3

FB3

EN3

FB1

EN1

2.5V TO 5.5V

SWC

SWD

SWG

SWH

2.25V TO 5.5V

2.2µH

2.2µH

2.2µH

2.2µH

FB4

EN4

FB2

EN2

TEMP

PGOODALL

PLL/MODE

RT

3370 TA01a

GND

LOAD CURRENT (mA)

1

10

100

1000 4000

0

10

20

30

40

50

60

70

80

90

100

3370 TA01b

1A BUCK

2A BUCK

3A BUCK

4A BUCK

L = 3.3µH

Burst Mode OPERATION