Preliminary

Rev.01

1/16

EP1551

1 MHz Five-channel Power Supply

FEATURES

Up to 95% efficiency

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Step-up and up to 92%

efficient Step-down converters

Combine

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Step-up and Step-down for up to 87%

efficiency buck-boost operations

Minimum 0.7V input voltage

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2µA shutdown mode

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Intern

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al soft start control

Overload protection

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Compact

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QFN-32 5 x 5 mm package

APPLICATIONS

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Digital still camera

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Digital video camera

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PDA

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MP3

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PMP

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Portable DVD Player

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Car navigation

DESCRIPTION

The EP1551 is a small, high efficiency, five-channel, power-supply for digital still and video cameras. It consists

of:

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Step-up DC-DC converter with on-chip power MOSFETs for 3.3V main system supply with up to 95%

efficiency. It accepts inputs from 0.7V to 5.5V and regulates a resistor-adjustable output from 2.7V to 5.5V.

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Step-down main DC-DC converter with on-chip power MOSFETs for 1.5V DSP core supply with up to 92%

efficiency. It can operate from the Step-up main system supply providing buck-boost capability with up to 90%

compound efficiency, or it can run directly from battery if buck-boost operation is not needed.

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PWM controller with external FET for Step-up DC-DC converter for 5V motor actuator

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PWM controller with external FET for 15V LCD supply

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PWM controller with external FET and transformer for –7.5V and +15V CCD Bias

All DC-DC channels operate at one fixed frequency settable from 100KHz to 1MHz to optimize size, cost and

efficiency. Other features include soft-start, power-OK outputs, and overload protection. The EP1551 is available

in apace saving QFN-32 5 x 5 mm packages. An evaluation kit is also available to expedite design.