LP5526TL NSC [National Semiconductor], LP5526TL Datasheet - Page 20

• Manufacturer Part Number: LP5526TL
• Description: Lighting Management Unit with High Voltage Boost Converter with up to 150mA Serial FLASH LED Driver
• Manufacturer: NSC [National Semiconductor]

www.national.com
Backlight Drivers
FADE IN / FADE OUT
LP5526 has an automatic fade in and out for main and sub
backlight. The fade function is enabled with EN_FADE bit.
The slope of the fade curve is set by the SLOPE bit. Fade
control for main and sub display is set by FADE_SEL bit.
Recommended fading sequence:
1. Set SLOPE
2. Set FADE_SEL
3. Set EN_FADE = 1
4. Set EN_MAIN / EN_SUB = 1
5. Set target WLED value
6. Fading will be done either within 0.65s or 1.3s based on
Fading times apply to full scale change i.e. from 0 to 100% or
vice versa. If the current change does not correspond to full
scale change, the time will be respectively shorter. See
WLED Dimming diagrams for typical fade times.
Note: if DISPL=1 and FADE_SEL=0 then FADE effects MAIN and SUB
FADE_SEL
EN_FADE
EN_MAIN
EN_SUB
SLOPE
SLOPE selection
DISPL
Name
WLED CONTROL REGISTER (03H)
Bit
5
4
3
2
1
0
FADE execution time:
0 = 1.3s (full scale)
1 = 0.65s (full scale)
FADE selection:
0 = FADE controls MAIN
1 = FADE controls SUB
FADE enable
0 = FADE disabled
1 = FADE enabled
Display mode:
0 = MAIN and SUB individual control
1 = MAIN and SUB controlled with
MAIN DAC
MAIN enable:
0 = disable
1 = enable
SUB enable:
0 = disable
1 = enable
(Continued)
Description
20
Adjustment is made with 04H (main current) and with 05H
(sub current) registers:
MAIN CURRENT [7:0]
SUB CURRENT [7:0]
0000 0000
0000 0001
0000 0010
0000 0011
1111 1101
1111 1110
1111 1111
…
…
Driver current,
mA (typical)
25.3
25.4
25.5
0.1
0.2
0.3
…
…
0