© 2006 Semtech Corp.

POWER MANAGEMENT

SC614

United States Patent No. 6,504,422

www.semtech.com

19

POWER MANAGEMENT

Application Examples (Cont.)

Main Backlight Plus RGB Indicator

D1

LED

C2

1u

D2

LED

D3

LED

D4

LED

D5

C1

2u2

C3 1u

C4 1u

VIN

11

VIN

17

EN

2

SDA

7

SCL

8

ASEL

5

SDIM

3

MDIM

4

FL

6

VOUT

9

VOUT

16

M1

1

M2

24

M3

23

M4

22

S1/FL3

20

S2/FL2

19

S3/FL1

18

GND

12

GND

21

U1

SC614

SDA

EN

SDIM

SCL

FL

MDIM

VBAT

R1

Pull-up

VLOGIC

R2

Pull-up

Note: R1 and R2

pull-up resistors are a

requirement of the I2C

specification

MAIN BACKLIGHT

RGB INDICATOR

RGB_LED

102mA Max

102mA Max

102mA Max

102mA Max

328mA Max Continuous

102mA Max

102mA Max

102mA Max

434mA Max (500ms)

Features:

•

Up to 4 LED main backlight with up to 32mA per LED

•

PWM dimming of backlight using MDIM pin

•

3 current sinks for RGB with up to 32mA per LED

•

Register Settings (20mA backlight currents and as required on the fly RGB current used as an example):

0x00: set to 0x7F to enable all 7 current sinks for use

0x01 through 0x04: set to 0x32 for 20mA per current sink

0x05 through 0x07: set to as required on the fly for each color

0x08: set to 0x00 for Flash Mode disabled (FL pin inactive) and 250kHz charge pump frequency