Functionality of Color LED

Outputs (RLED, GLED, BLED)

LP5526 has one RGB/color LED output, consisting of three

individual LED output pins. Output pins can be used in

switch mode or constant current mode. Output mode can be

selected with the control register (address 00H) bit CC_SW.

If the bit is set high, then RGB outputs are in switch mode,

otherwise in constant current mode. These modes are de-

scribed later in separate chapters.

RGB LED output control can be done in three ways:

1.

Defining the expected color and brightness with internal

PWM in RGB register (address 01H)

2.

Direct setting each LED ON/OFF via RGB Control reg-

ister (address 00H)

3.

External PWM control

1. BRIGHTNESS CONTROL WITH RGB REGISTER

If the RGB LED output is used by defining the balance and

brightness in the RGB register, then one needs to set EN-

_RGB bit high and RGB_PWM bit high in the Control register

(address 00H). RSW, GSW and BSW are used to enable

each LED output, enabled when written high. CC_SW de-

fines the LED output mode. A single register is used for

defining the color and brightness for the RGB LED output.

OVL bit selects overlapping/non-overlapping mode. Overlap-

ping mode is selected when OVL = 1.

CONTROL REGISTER (00H)

Name

Bit

Description

RGB_PWM

7

0 = Internal PWM control disabled

1 = Internal PWM control enabled

EN_RGB

6

0 = RGB outputs disabled

1 = RGB outputs enabled

CC_SW

5

0 = Constant current sink mode

1 = Switch mode

RSW

3

0 = RLED disabled

1 = RLED enabled

GSW

2

0 = GLED disabled

1 = GLED enabled

BSW

1

0 = BLED disabled

1 = BLED enabled

RGB REGISTER (01H)

COLOR[3:0]

7:4

Color for RGB LED output

BRIGHT[2:0]

3:1

Brightness control

OVL

0

0 = Non-overlapping mode

1 = Overlapping mode

Brightness control is logarithmic and is programmed as fol-

lows:

Bright[2:0]

Brightness [%]

Ratio to max

brightness

000

0

0

001

1.56

1/64

010

3.12

1/32

011

6.25

1/16

100

12.5

1/8

101

25

1/4

110

50

1/2

111

100

1/1

16 colors can be selected as follows. Please note that exact color depends on RGB LED current and type. Color setting is

valid only in non-overlapping mode.

COLOR[3:0]

RED

active [%]

GREEN

active [%]

BLUE

active [%]

RGB COLOR

0000

100

0

0

red

0001

0

100

0

green

0010

0

0

100

blue

0011

50

50

0

yellow

0100

0

50

50

cyan

0101

50

0

50

magenta

0110

33

33

33

white

0111

50

25

25

pink

1000

25

50

25

light green

1001

25

50

25

light blue

1010

25

25

50

orange

1011

75

25

0

deep pink

1100

0

75

25

spring green

1101

25

75

0

lawn green

1110

0

25

75

sky blue

1111

25

0

75

indigo

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