RT8489

2

DS8489-00 November 2012

www.richtek.com

©

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.

RT8489

Package Type

S : SOP-24

Lead Plating System

G : Green (Halogen Free and Pb Free)

Pin Configurations

SOP-24

(TOP VIEW)

LED1

GATE1

LED2

SENSE1

GATE2

SENSE2

LED3

VCC

GBIAS

GATE

GND

ISENSE

RSET

EN

GATE3

OVP

SENSE3

SS

LED4

VC

GATE4

ACTL

SENSE4

DCTL

6

7

8

9

10

11

12

4

5

2

3

21

22

23

18

19

20

16

13

17

24

15

14

Marking Information

RT8489GS : Product Number

YMDNN : Date Code

RichTek

RT8489

GSYMDNN

Functional Pin Description

Pin No.

Pin Name

Pin Function

1

VCC

Power Supply Input. For good bypass, a low ESR capacitor is needed between

this pin and GND.

2

GBIAS

Internal Gate Driver Bias Voltage (around 10V) Pin. A good bypass capacitor

between this pin and GND is needed.

3

GATE

Gate of External MOSFET. For the Boost PWM control loop.

4

GND

Ground.

5

ISENSE

Current Sense Input. Connect a sense resistor from this pin to GND. The switch

current sense signal is used for boost current mode PWM loop control and power

switch over current protection.

6

RSET

Switching Frequency Set Pin. Put a resistor from RSET to GND to program the

7

EN

Enable Control Input (Active High).

8

OVP

Over Voltage Protection Sense Input. OVP pin threshold is around 1.23V. Use a

resistor divider from Output to GND to program the OVP level.

9

SS

Soft-Start. Connect a soft-start capacitor from SS pin to GND to adjust the

soft-start time. An internal 8

μA constant current charges external capacitor during

soft-start period.

10

VC

Loop Compensation.

11

ACTL

Analog/PWM Dimming Control Input. When used in analog dimming, ACTL

control range is from 0.4V to 1.4V.

12

DCTL

Digital PWM Dimming Control Input. By adding a 0.1

μF filter capacitor on the

ACTL pin, the PWM dimming signal on the DCTL pin will be averaged out and

converted into analog dimming signal on the ACTL pin.