RT9525

2

DS9525-01 May 2011

www.richtek.com

Functional Pin Description

Pin No.

Pin Name

Pin Function

1

TS

Thermistor Monitor Input. The TS pin connects to a battery’s thermistor to

determine if the battery is too hot or too cold to charge. If the battery’s temperature

is out of range, charging is paused until it re-enters the valid range. TS also detect

whether the battery (with NTC) is present or not

2, 3

BAT

Battery Connect Pin.

4

EN

Charge Enable, Active-low input. 200k

Ω pull low.

5

EN2

6

EN1

Input Current Limit Configuration Setting.

7

PGOOD

Power Good Status Output. Active-low, open-drain output.

8,

17 (Exposed Pad)

GND

Ground. The exposed pad must be soldered to a large PCB and connected to

GND for maximum power dissipation.

9

CHG

Charger Status Output. Active-low, open-drain output.

10, 11

SYS

System Connect Pin. Connect this pin to system load with a minimum 10uF MLCC

to GND.

12

NC

No Internal Connection.

13

VIN

Supply Voltage Input.

14

TIMER

Safe Charge Timer Setting.

15

SYSOFF

System Disconnect Pin. Pull SYSOFF high to disconnect SYS from battery,

connect to GND for normal operation. Internally pulled up by 1

μA current source to

BAT.

16

ISETA

Typical Application Circuit

VIN

GND

RT9525

SYS

16

8, 17 (Exposed Pad)

2, 3

13

10, 11

BAT

ISETA

+

Adapter or USB

4

SYSOFF

15

2.2µF

1µF

1

TS

10µF

EN

Chip Enable

Disconnect

Connect

EN1

EN2

6

5

7

9

CHG

TIMER

14

1µF

PGOOD