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DS9986-00 May 2011

www.richtek.com

RT9986

Functional Pin Description

Pin No.

Pin Name

Pin Function

1

FB1

Feedback Input Pin of CH1.

2

VREF

1.8V Reference Output Pin.

3

FB6

Feedback Input Pin of CH6.

4

VOUT6

Sense Input Pin of CH6 Inverting Output Node.

5

FB7

Feedback input pin of CH7 in step-up mode or current sink pin of CH7 in current

source mode.

6

PVDD7

Power Output Pin of CH7.

7

LX7

Switch Node of CH7 in Step-Up Mode. LX7 initial voltage determines CH7

operation mode.

8

EN7

Enable Pin of CH7 and PWM Dimming Signal Input Pin.

9

LX4

Switch Node of CH4.

10

PVDD4

Power Input Pin of CH4.

11

FB4

Feedback Input Pin of CH4.

12

VCHK

Sense Pin of Voltage Detector.

13

VNEG

Output Pin of Negative Regulator.

14

FB3

Feedback Input Pin of CH3.

15

PVDD3

Power Input Pin of CH3.

16

LX3

Switch Node of CH3.

17

RST

Voltage Detector Open Drain Output Pin.

18

FB5

Feedback Input Pin of CH5.

19

PVDD5

Power Output Pin of CH5.

20

LX5

Switch Node of CH5.

21

VDDM

IC Analog Power Pin.

22

RTCPWR

Internal Control Circuit Power Pin. That must connect to a bypass capacitor for

better noise rejection.

23

SYSR

System Reset Open-Drain Output Pin.

24

FB2

Feedback Input Pin of CH2.

25

EN1234

Enable Pin of CH1, CH2, CH3, CH4.

26

LX2

Switch Node of CH2.

27

PVDD2

Power Input Pin for Step-Down of CH2.

Power Output Pin for Step-Up of CH2.

28

LX6

Switch Node of CH6.

29

BAT

Battery Power Pin.

30

PVDD1

Power Output Pin of CH1.

31

LX1

Switch Node of CH1.

32

EN56

Enable Pin of CH5, CH6.

33 (Exposed pad) GND

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

GND for maximum thermal dissipation.