AAT2869 Advanced Analogic Technologies, Inc., AAT2869 Datasheet - Page 12

• Manufacturer Part Number: AAT2869
• Description: Fade-in/fade-out 4 Channel Backlight Driver With Dual Ldos
• Manufacturer: Advanced Analogic Technologies, Inc.

AS
500μs t
backlighting is enabled with default 20mA LED current
each.
Address 0 – Backlight Enable and Fade Enable
The BL_ENB bit of address register 0 is adopted to
enable or disable the white LED backlighting. 0 enables
backlighting; 1 disables backlighting. The FADE_EN and
FADE_IN bits are adopted to enable/disable the fade-in/
fade-out function. The other bits of the register should
be written with data 0.
For example, to enable a 20mA fade-in visual effect,
send 4 data EN/SET rising edges after an EN/SET low
lasting for t
17 address EN/SET rising edges.
12
SystemPower
0 [Default]
Number
2
Cwire Registers
Backlight on, Fade enabled: fade out
Backlight on, Fade enabled: fade in
1
2
3
4
5
OFF
time, data 0 is written to address 0 and LED
Address
LAT
Backlight on [default]
or send 4 data EN/SET rising edges after
EN/SET Rising
Description
Backlight on
Backlight off
Floor 0.5mA [default]
TM
Edges
Description
Floor 1.0mA
Floor 2.0mA
Floor 3.0mA
17
18
19
20
21
22
Fade-In/Fade-Out 4 Channel Backlight Driver with Dual LDOs
Backlight Floor Level
LDO Output Voltage
LDO Enable Control
Backlight Enable
Backlight LSBs
Backlight MSB
Table 1: AAT2869 AS
Table 2: AS
Table 3: AS
Function
BL_ENB
w w w . a n a l o g i c t e c h . c o m
0
0
0
0
1
2
2
Cwire Register Address 0.
Cwire Register Address 1.
LDO[3]
BL[3]
D3
FADE_EN
0
0
0
0
2
0/1
Cwire Registers.
Address 1 – Backlight Fade Floor Settings
When the fade-out function is enabled, the LED current
decreases to the programmed floor level instead of
decreasing to zero. The other bits of the register should
be written with data 0.
Addresses 2 and 3 –
LED Current Level Settings
The LED current level is set via the AS
a linear scale by 32 codes where the LED current of each
higher code is higher than the lower one, as shown in
Table 4. In this manner, the LED current decreases lin-
early with each decreasing code.
0
0
1
1
FLOOR[1]
BL_ENB
LDO[2]
BL[2]
D2
0
0
0
0
0
1
1
FADE_IN
0/1
FLOOR[1]
LDOA_EN
FADE_EN
0
1
0
1
LDO[1]
BL[1]
D1
0
PRODUCT DATASHEET
Data
FLOOR[2]
LDOB_EN
FADE_IN
EN/SET Rising Edges
LDO[0]
BL[4]
BL[0]
D0
AAT2869
FLOOR[2]
5 ~ 8
2
EN/SET Rising
2
Cwire interface in
1
3
4
0
1
0
1
2869.2010.01.1.0
Edges
1 ~ 16
1 ~ 16
1 or 2
1 ~ 8
1 ~ 4
1 ~ 4