RT9503

2

DS9503-03 April 2011

www.richtek.com

Typical Application Circuit

Functional Pin Description

Pin No.

Pin Name

Pin Function

1

ACIN

Wall Adaptor Charge Input Supply.

2

USB

USB Charge Input Supply.

3

CHG_S

Charge Status Indicator Output (open drain).

4

AC_PGOOD

Wall Adaptor Power Good Indicator Output (open drain).

5

GND

Ground.

6

ISETA

Wall Adaptor Supply Charge Current Set Point.

7

ISETU

USB Supply Charge Current Set Input (active low).

8, 14

NC

No Internal Connection.

9

EN

Charge Enable (Active Low).

10

TIMER

Safe Charge Timer Setting.

11

TS

Temperature Sense Input.

12

BATT

Battery Charge Current Output.

13

BAT_ON

Power path controller output, low to turn on the external P-MOSFET.

15

SYS

System Voltage Detecting Pin.

16

AC_ON

P-MOSFET Switch Control Output (open drain).

17 (Exposed Pad) GND

The exposed pad must be soldered to a large PCB and connected to GND for

maximum power dissipation.

RT9503

3

4

1

BATT

TIMER

SYS

11

12

13

6

ACIN

ISETA

TS

10

15

2

USB

Battery Pack

0.1uF

Chip Enable

5, Exposed Pad (17)

GND

9

EN

AC_PGOOD

AC_ON

CHG_S

BAT_ON

USB

Adapter

1uF

System

7 ISETU

16

1uF

10uF

1uF