UNISONIC TECHNOLOGIES CO., LTD

UC3655

CMOS IC

www.unisonic.com.tw

1 of 9

Copyright © 2014 Unisonic Technologies Co., Ltd

QW-R502-280.F

500mA SYNCHRONOUS

STEP-DOWN DC/DC

CONVERTERS



DESCRIPTION

The UTC UC3655 is a synchronous-rectification type DC/DC

converters with a built-in 0.6Ω P-channel driver transistor and 0.7Ω

N-channel switching transistor, which designed to allow the use of

ceramic capacitors. Using only a coil and two capacitors connected

externally, the UC3655 enable a high efficiency, stable power supply

with an output current of 500mA to be configured. Its operating voltage

is 2.0V and the output voltage is programmable in a range from 0.9V to

4.0V in increments of 0.1V (accuracy: ±2.0%) internally. The oscillation

frequency is 1.3MHz.

For operation mode, it is PWM control in the UTC UC3655, the UTC

UC3655

series is automatic PWM/PFM switching control, allowing fast

response, low ripple and high efficiency over the full range of load.

Internal soft start and current control functions are built in it. All

circuits are shutdown to reduce current consumption to as low as 1.0μA

or less during standby mode. With the built-in Under Voltage Lock Out

(U.V.L.O.) function, when input voltage becomes 1.4V or lower the

internal P channel driver transistor is forced OFF.



FEATURES

* Very High Efficiency 92%

* Low Ripple Rejection Voltage 10mV

* Oscillation Frequency is 1.3MHz

* With PWM / PFM Automatic Switching Control

* Maximum Duty Ratio is 100%

* Ceramic Capacitor Available



ORDERING INFORMATION

Ordering Number

Package

Packing

Lead Free

Halogen Free

UC3655L-xx-AF5-R

UC3655G-xx-AF5-R

SOT-25

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