RT8509

®

DS8509-01 March 2012

www.richtek.com

1

©

Copyright 2012 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

Ordering Information

Note :

Richtek products are :

RoHS compliant and compatible with the current require-

ments of IPC/JEDEC J-STD-020.

Suitable for use in SnPb or Pb-free soldering processes.

Pin Configurations

WDFN-10L 3x3

(TOP VIEW)

3A, 14V Step-Up DC/DC Converter

General Description

The RT8509 is a high performance switching boost

converter that provides a regulated supply voltage for active

matrix thin film transistor (TFT) liquid crystal displays

(LCDs).

The RT8509 incorporates current mode, fixed-frequency,

pulse width modulation (PWM) circuitry with a built in

N-MOSFET to achieve high efficiency and fast transient

response.

The RT8509 has a wide input voltage range from 2.8V to

14V. In addition, the output voltage can be adjusted up to

24V via an external resistive voltage divider. The maximum

peak current is limited to 4.5A (typ.). Other features include

programmable soft-start, over voltage protection, and over

temperature protection.

The RT8509 is available in a WDFN-10L 3x3 package.

Features

90% Efficiency

Adjustable Output Up to 24V

2.8V to 14V Input Supply Voltage

Input Supply Under Voltage Lockout

Fixed 1.2MHz Switching Frequency

Programmable Soft-Start

Over Temperature Protection

Thin 10-Lead WDFN Package

RoHS Compliant and Halogen Free

Applications

GIP TFT LCD Panels

Marking Information

H4= : Product Code

YMDNN : Date Code

Typical Application Circuit

COMP

FB

GND

GND

SS

VIN

VSUP

LX

LX

EN

9

8

7

1

2

3

4

5

10

6

11

H4=YM

DNN

LX

RT8509

VIN

EN

VSUP

FB

SS

COMP

GND

Chip Enable

2

10

1

R1

R2

18V

R3

C1

6, 7

9

3

8

C2

R4

12V

4, 5, 11 (Exposed Pad)

L1

D1

10µF x 2

10

1µF

4.7µH

134k

10k

4.7µF x 3

33nF

56k

1nF

C3

1µF

Package Type

QW : WDFN-10L 3x3 (W-Type)

RT8509

Lead Plating System

G : Green (Halogen Free and Pb Free)