PRODUCT DATASHEET
AAT2861
TM
ChargePump
Backlight/Flash LED Driver and Multiple LDO Lighting Management Unit
EN/SET
Address Rising Edges
Function
D3
D2
D1
D0
0
1
2
3
4
5
6
7
8
17
18
19
20
21
22
23
24
25
26
27
28
29
Backlight Main/Sub ON/OFF and Fade Enable FADE_SUB
FADE_MAIN
X
BLM[2]
X
BLS[2]
X
OFF_LDOC
LDOA[2]
LDOB[2]
LDOC[2]
F_HI[2]
X
SUB_ON
FLOOR[1]
BLM[1]
MEQS
BLS[1]
X
MAIN_ON
FLOOR[0]
BLM[0]
BLM[4]
BLS[0]
Backlight Fade Control
Backlight Current Main, LSB's
Backlight Current Main, MSB
Backlight Current Sub, LSB's
Backlight Current Sub, MSB
LDO Disable Control
X
BLM[3]
Reserved
BLS[3]
X
BLS[4]
X
OFF_LDOB OFF_LDOA
LDO A Output Voltage Control
LDO B Output Voltage Control
LDO C Output Voltage Control
Flash Current
LDOA[3]
LDOB[3]
LDOC[3]
F_HI[3]
X
LDOA[1]
LDOB[1]
LDOC[1]
F_HI[1]
F_TIME[1]
OFF_ BL2
LDOA[0]
LDOB[0]
LDOC[0]
F_HI[0]
F_TIME[0]
OFF_ BL1
9
10
11
12
Flash Timer Control
LED Channel Disable Control (BL1 – BL4)
OFF_BL4
OFF_ BL3
LED Channel Disable Control (BL5, BL6,
BL7/FL2, FL1)
13
30
OFF_FL1
OFF_BL7/FL2
OFF_BL6
OFF_BL5
Table 1: AAT2861- 1 Configuration/Control Register Allocation
(* signifies that the data bit has a POR default bit value = 1; X signifies “Don’t care”).
current threshold (set by Address 1) at which point the
BL channels will be turned off. The default fade-out cur-
rent level is 500μA, but can be changed to 1mA, 2mA or
3mA using the data codes listed in Table 3.
Sub
Main
Sub
Main
Data
Fade On Fade On Channel Channel
1*
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
No*
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No*
No
No
Off*
Off
On
On
Off
Off
On
On
Off
Off
On
On
Off
Off
On
On
Off*
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Data
Fade Out Current Level (mA)
No
1*
2
0.50*
1.0
Yes
Yes
Yes
Yes
No
No
No
No
Yes
Yes
Yes
Yes
3
2.0
4
3.0
Table 3: Backlight Fade-In and Fade-Out Control
(Address 1).
Backlight Current Control (Addresses 2 to 5)
The AAT2861’s AS2Cwire Addresses 2, 3, 4, and 5 control
the backlight LED output current level in Main and Sub
group of outputs. Address 2 and Address 3 control the
Main backlight channel current to one of 32 levels
according to Table 4 below. Address 3 acts as the MSB
and Address 2 acts as the LSB for the current level
setup. Address 4 and Address 5 control the Sub back-
light channels current to one of 32 levels according to
Table 5 below.
Table 2: Backlight Main/Sub ON/OFF and Fade
Enable (Address 0).
Backlight Fade-In and Fade-Out Control
(Address 1)
During the fade-out cycle, the LED current will be
decreased linearly down to its programmed fade-out
*Denotes the default (power-on-reset) value
w w w . a n a l o g i c t e c h . c o m
2861.2009.02.1.2
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AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
