UNISONIC TECHNOLOGIES CO., LTD

UC3666

Preliminary

CMOS IC

www.unisonic.com.tw

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Copyright © 2010 Unisonic Technologies Co., Ltd

QW-R502-489.a

DUAL CHANNEL 800mA HIGH

EFFICIENCY STEP-DOWN

DC/DC CONVERTER

DESCRIPTION

The UTC UC3666 is a dual channel high efficiency step-down

DC/DC converter with constant frequency and current mode. A

main switch and a synchronous rectifier for high efficiency are

contained in each converter, and thus an external Schottky diode is

saved. Supply current is only 300μA during normal operation and is

reduced to less than 1μA in shutdown mode. The output voltage

can be adjusted to as low as 0.6V. With input voltage range from

2.5V ~ 5.5V , each converter can deliver 800mA current to the

load. Due to the internally fixed 1.8MHz switching frequency , small

surface mount inductors and capacitors can be used. It can also

run 100% duty cycle for low dropout applications.

The UTC UC3666 is generally used in digital still cameras,

portable instruments, slim-type DVD, microprocessors and DSP

core supplies, wireless and DSL card, PDAs, smart phones,

cellular telephones and so on.

FEATURES

* high efficiency

* Current mode operation

* Low quiescent current less than 300uA (Active mode)

* Input voltage varying from 2.5V to 5.5V

* Output current on each channel: 800mA

* Fixed frequency operation

* 0 - 100% full duty ratio in dropout

* 0.6V reference allows low output voltages

* Over-temperature protection circuit

* Shutdown current less than 0.1μA

* RoHS Compliant (100% green available)

* Halogen Free

SON-10

1

ORDERING INFORMATION

Ordering Number

Package

Packing

Lead Free

Halogen Free

UC3666L-B10-R

UC3666G-B10-R

SON-10

Tape Reel

Note: xx: Output Voltage, refer to Marking Information.