PC POWER SUPPLY SUPERVISORS

DESCRIPTION

The UTC 3563 is a monolithic control circuit containing the

primary functions required for DC to DC converters and

highside-sensed constant current source. The device consists of

an internal temperature compensated reference, comparator,

controlled duty cycle oscillator with an active current sense circuit,

bootstrapped driver, and high current output switch. This device is

specifically designed to construct a constant current source for

battery chargers with a minimum number of external components.

Bootstrapped driver can drive the NPN output switch to saturation

for higher efficiency and less heat dissipation. The UTC 3563 can

deliver 1.5A continuous current without requiring a heat sink.

APPLICATIONS

*Constant current source for battery chargers.

*Saver for cellular phones.

*Step-Down DC-DC converter module.

FEATURES

* 3V to 30V input voltage operation.

* Internal 2A peak current switch.

* 1.5A continuous output current.

* Bootstrapped driver.

* High side current sense capability.

* High efficiency (up to 90%)

* Internal 2% reference.

* Low quiescent current at 1.6mA.

* Frequency operation from 100Hz to 100KHz