 DESCRIPTION

UTC P1888 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 P1888 can provide low-ripple power, high efficiency, and

excellent transient characteristics and an enable function, an over

current protect function and a short circuit protect function are built

inside, so the operation frequency will be reduced from 300KHz to

30KHz when OCP or SCP happens. And 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 count an internal compensation

block is built in.

UTC P1888 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. It provides such

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

the operation via an AC adapter because this converter can

accommodate an input voltage up to 23V.

 FEATURES

* Soft-start, Current Limit, Enable function

* Thermal Shutdown function

* Built-in internal SW P-channel MOS

* Input voltage: 4V~23V.

* Output voltage: 1.23V~VCC.

* Duty ratio: 0% to 100% PWM control

* Oscillation frequency: 300KHz typ.