AAT2846INJ-EE-T1 AnalogicTech, AAT2846INJ-EE-T1 Datasheet - Page 14

• Manufacturer Part Number: AAT2846INJ-EE-T1
• Description: High Current Charge Pump with Dual LDO for Backlight and Flash Applications
• Manufacturer: AnalogicTech

Flash Current FL1, FL2 (Address 4)
The current level for the flash channels FL1 and
FL2 is programmed by Address 4. Data 1 enables
the maximum current level. The maximum current
level is determined by the value of R
and Figure 3 illustrate the additional flash current
levels that are available.
14
Table 4: Data Code for the Flash Current
Figure 3: Data Code for Address 4 vs.
120
100
80
60
40
20
percentage of Flash Current Level.
0
Data
1
10
12
13
14
15
16
11
1
2
3
4
5
6
7
8
9
2
I
FLED
at Data 1
3
Control, Address 4.
= 100%
4
5
6
Data Code
7
Flash LED Current
8
(% of Maximum)
9
10 11 12 13 14 15 16
100
87
77
66
58
50
44
39
35
30
27
24
20
17
16
14
I
FLED
at Data 16
FSET
= 14%
. Table 4
High Current Charge Pump with Dual LDO
for Backlight and Flash Applications
Independent Flash ON/OFF Control
(Address 5)
Use Address 5 to program which flash channels
are active. By default, both flash channels are OFF
at startup. After writing to Address 4 to program the
desired flash channel current level, write to
Address 5 to enable a single channel or both chan-
nels according to Table 5.
Writing to Address 5 enables the flash channels
indefinitely. FL1 and FL2 will remain ON until
Address 5 is re-programmed to OFF, ENS is
strobed low to shutdown the device, or the flash
safety timer times out after FEN has been strobed
high. The flash safety timer is always activated
when FEN is taken high. The Address 5 data set-
ting is always reset to Data 1 when the flash timer
expires or when FEN is strobed low.
Maximum Backlight Current (Address 12)
There are two separate current level scales that apply
to Addresses 0-2: 20mA and 30mA. According to the
Maximum Backlight Current setting at Address 12,
only one of the two scales can be active at any given
time and never both. By default, the 20mA scale is
active on startup. To change to the 30mA scale, or go
back to the 20mA scale, write to Address 12.
Since only one of the scales can be active at any
given time, the 20mA and 30mA scales cannot be
mixed between main and sub. When setting Address
12 to the 30mA scale, only current levels from that
scale can be mixed between main and sub.
Table 6: Data Code for the Maximum Current
Table 5: Output Enable Control, Address 5.
Data
1
2
3
4
Data
1
2
Settings, Address 12.
FL1
Off
Off
On
On
Maximum Current
20mA
30mA
AAT2846
2846.2007.08.1.0
FL2
Off
On
Off
On