3

RT8525D

DS8525D-00 June 2012

www.richtek.com

©

Copyright 2012 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

Function Block Diagram

UVLO

12V LDO

OTP

+

-

+

-

OVP/OUVP

Logic

Q

Q

S

R

OSC

+

-

OC

+

-

Blanking

PWM

Controller

-

+

-

EA

0.1V

2.5V

0.4V

1.25V

4µA

FAULT

Protection

FAULT

VDC

VIN

FSW

OVP

DRV

ISW

FB

COMP

SS

EN

GND

Operation

The RT8525D is a wide input operating voltage range and

current mode step up controller. High voltage output and

large output current are feasible by using an external N-

MOSFET.

The error amplifier EA adjusts COMP voltage by comparing

the feedback signal from the output voltage with the internal

1.25V reference.

Fault Protection

The protection functions include output over voltage, output

under voltage, over temperature protection. The FAULT

pin will be pulled low once a protection is triggered, and a

can refer to the Figure 2. Fault Protection Function Block.

Blanking

N-MOSFET current is measured by external RS. The slope

compensator works together with sensing voltage of

avoid noise and parasitism effect.