P1785G-S08-R datasheet(5/7 Pages) UTC

5 / 7 page

P1785

Preliminary

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

5 of 7

www.unisonic.com.tw

QW-R103-043.b

FUNCTION DESCRIPTION

PWM Control

The UTC P1785 consists of DC/DC converters which employ a PWM system. In this DC/DC converter, the pulse

width varies in a range from 0 to 100% which is according to the load current. Cause the switching frequency

remains constant the ripple voltage which produced by the switching can be removed easily through a filter.

Therefore, these converters provide a low-ripple power over broad ranges of input voltage and load current.

Under Voltage Lockout

The under voltage lockout circuit makes sure that the outputs of high-side MOSFET driver remain in the off state

after the supply voltage drops below 3.3V. When VCC rises above 3.5V normal operation resumes.

RDS(ON) Current Limiting

The current limit threshold is fixed by the external resistor which is connected from VCC supply to OCSET. An

over-current condition is triggered when the PWM voltage is less than the voltage at OCSET.

ILOAD × RDS(ON) = IOCSET × ROCSET

above formula is setting the current limit value.

P1785G-S08-R Datasheet(PDF) 5 Page - Unisonic Technologies