lp5526tlx National Semiconductor Corporation, lp5526tlx Datasheet - Page 12

• Manufacturer Part Number: lp5526tlx
• Description: Lighting Management Unit With High Voltage Boost Converter With Up To 150ma Serial Flash Led Driver
• Manufacturer: National Semiconductor Corporation

www.national.com
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
2. Direct setting each LED ON/OFF via RGB Control reg-
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.
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.
PWM in RGB register (address 01H)
ister (address 00H)
COLOR[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
active [%]
RED
100
50
50
33
50
25
25
25
75
25
25
0
0
0
0
0
active [%]
GREEN
100
50
50
33
25
50
50
25
25
75
75
25
0
0
0
0
12
Brightness control is logarithmic and is programmed as fol-
lows:
BRIGHT[2:0]
COLOR[3:0]
RGB_PWM
EN_RGB
CC_SW
Bright[2:0]
Name
RSW
GSW
BSW
OVL
000
001
010
011
100
101
110
111
active [%]
CONTROL REGISTER (00H)
BLUE
7:4
3:1
Bit
7
6
5
3
2
1
RGB REGISTER (01H)
0
100
50
50
33
25
25
25
50
25
75
75
0
0
0
0
0
Brightness [%]
Description
0 = Internal PWM control disabled
1 = Internal PWM control enabled
0 = RGB outputs disabled
1 = RGB outputs enabled
0 = Constant current sink mode
1 = Switch mode
0 = RLED disabled
1 = RLED enabled
0 = GLED disabled
1 = GLED enabled
0 = BLED disabled
1 = BLED enabled
Color for RGB LED output
Brightness control
0 = Non-overlapping mode
1 = Overlapping mode
1.56
3.12
6.25
12.5
100
25
50
0
RGB COLOR
spring green
lawn green
light green
deep pink
light blue
magenta
sky blue
orange
yellow
Ratio to max
indigo
green
white
cyan
blue
pink
brightness
red
1/64
1/32
1/16
1/8
1/4
1/2
1/1
0