UNISONIC TECHNOLOGIES CO., LTD

P1786

LINEAR INTEGRATED CIRCUIT

www.unisonic.com.tw

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Copyright © 2009 Unisonic Technologies Co., Ltd

QW-R103-038.B

PWM CONTROL 3A

STEP-DOWN CONVERTER

DESCRIPTION

UTC P1786 consists of 3A step-down switching regulator control

which includes a reference voltage source, oscillation circuit, error

amplifier, internal PMOS and etc with PWM.

UTC P1786 can provide low-ripple power, high efficiency, and

excellent transient characteristics. An enable function, an over

current protect and short circuit protect function are built inside, so

the operation frequency can be reduced from 300KHz to 30KHz

when OCP or SCP happens. The PWM control circuit can vary the

duty ratio linearly from 100 down to 0%. This converter also includes

an error amplifier circuit as well as a soft-start circuit that prevents

overshoot at startup. Also, to minimum external component counts

for an internal compensation block is built in.

These ICs can work as step-down switching regulators with the

addition of an internal P-channel Power MOS, a coil, capacitors, and

a diode connected externally. They provide such outstanding

features: low current consumption. It is also suitable for the

operation via an AC adapter because this converter accommodate

an input voltage up to 23V.

FEATURES

* Input voltage: 4.0V ~ 23V

* Duty ratio: 0% to 100% PWM control

* Oscillation frequency: 300KHz typ.

* Soft-start, current limit, enable function

* Thermal shutdown function

* Built-in internal SW P-channel MOS

ORDERING INFORMATION

Ordering Number

Lead Free

Halogen Free

Package

Packing

P1786L-S08-R

P1786G-S08-R

SOP-8

Tape Reel