RT9903

Preliminary

4

DS9903-07 August 2007

www.richtek.com

Pin No.

Pin Name

Pin Function

1

CX

Charge Pump External Driver Pin.

2

INCD

Charge Pump Input Pin.

3

FB_CP

Charge Pump Feedback Pin.

4

RT

Frequency Setting Resistor Connection Pin.

5

EXT4

CH4 External Power Switch.

6

CS4

CH4 Current Sense Input Pin.

7

FB4

CH4 Feedback Input.

8

COMP4

CH4 Feedback Compensation Pin.

9

FB3

CH3 Feedback Input.

10

COMP3

CH3 Feedback Compensation Pin.

11

LX3

CH3 Switch Node.

12

EN3

CH3 Enable Input Pin.

13

EN1

CH1 Enable Input Pin.

14

EN2

CH2 Enable Input Pin.

15

EN4

CH4 Enable Input Pin.

16

PGND

Power Ground.

17

VDD

Power Input Pin.

18

LX1

CH1 Switch Node.

19

COMP1

CH1 Feedback Compensation Pin.

20

FB1

CH1 Feedback Input.

21

AGND

Analog Ground.

22

FB2

CH2 Feedback Input.

23

COMP2

CH2 Feedback Compensation Pin.

24

LX2

CH2 Switch Node.

Exposed Pad (25) GND

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

maximum power dissipation.

Functional Pin Description