RT9505

2

DS9505-02 April 2011

www.richtek.com

Functional Pin Description

Pin No.

Pin Name

Pin Function

1

ACIN

Wall Adaptor Charge Input Supply.

2, 7

NC

No Internal Connection.

3

CHG_S

Charge Status Indicator Output (open drain).

4

PGOOD

Power Good Indicator Output (open drain).

5

GND

Ground.

6

ISETA

Wall Adaptor Supply Charge Current Set Point.

8

EN

Charge Enable Input (active low).

9

TS

Temperature Sense Input.

10

BATT

Battery Charge Current Output.

11 (Exposed Pad) GND

Exposed pad should be soldered to PCB board and connected to GND.

Typical Application Circuit

RT9505

1uF

AC

Adapter

ACIN

GND

BATT

TS

ISETA

Battery Pack

1

3

4

5, Exposed Pad (11)

6

8

9

10

CHG_S

PGOOD

EN

To System

To System

Chip Shutdown

Chip Enable

0.1uF to 10uF

Pre-Charge Phase

Fast Charge

Phase

Constant Voltage

Phase &

Standby Phase

Re-Charge Phase

Programmed

Charge Current

4.1V Recharge

Threshold

2.8V Precharge

Threshold

1/10 Programmed

Charge Current

Charge

Complete

Battery

Voltage

Charging

Current