2

RT8525

www.richtek.com

DS8525-01 March 2012

©

Copyright 2012 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

Function Block Diagram

Functional Pin Description

Pin No.

Pin Name

Pin Function

1

VDC

Output of Internal Pre-Regulator.

2

VIN

IC Power Supply.

3

COMP

Compensation for Error Amplifier. Connect a compensation network to ground.

4

SS

External Capacitor to Adjust Soft-Start Time.

5

FSW

Frequency Adjust Pin. This pin allows setting the switching frequency with a resistor

from 50kHz to 600kHz.

6

AGND

Analog Ground.

7

PWMI

External Digital Input for Dimming Function.

8

FAULT

Open Drain Output for Fault Detection.

9

FB

Feedback to Error Amplifier Input.

10

OOVP

Sense Output Voltage for Over Voltage Protection and Under Voltage Protection.

11

ISW

External MOSFET Switch Current Sense Pin. Connect the current sense resistor

between the external N-MOSFET switch and ground.

12

EN

Chip Enable (Active High).

13

PGND

Power Ground of Boost Controller.

14

DRV

Drive Output for the N-MOSFET.

UVLO

12V LDO

OTP

+

-

+

-

OOVP/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

OOVP

DRV

ISW

FB

COMP

SS

EN

PWMI

AGND

PGND