AAT2846 Datasheet, PDF (13/25 Pages) Advanced Analogic Technologies – High Current Charge Pump with Dual LDO for Backlight and Flash Applications

AAT2846
High Current Charge Pump with Dual LDO
for Backlight and Flash Applications
EN/SET
Address
Address
T _HI
T _LO
T_LAT
1
2
17
18
0
Data
T_LAT
1
2 . . . n ≤ 16
1
Data Reg 1
0
n
Data Reg 2
0
Figure 1: AS²Cwire Serial Interface Timing.
Data
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
30mA Max (mA)
30.0
27.9
26.1
24.2
21.0
19.2
17.3
15.0
12.7
10.9
8.1
6.2
4.4
3.5
2.6
0
20mA Max (mA)
20.0
19.0
17.8
16.5
14.3
13.0
11.8
10.2
8.5
7.3
5.4
4.1
2.9
2.2
1.6
0
Table 2: Data Code for Backlight Current Level,
Address 0-2.
35.0
30.0
25.0
20.0
15.0
20mA (Full Scale)
10.0
30mA (Full Scale)
5.0
0.0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Data Code
Figure 2: Data Code for Address 0-2 vs.
Backlight Current Level.
The AAT2846 incorporates additional circuitry that
optimizes performance for exceptionally low back-
light current settings. A separate address is used to
activate this circuitry. To program the low current
settings with improved performance and efficiency,
write to Address 3. Unlike Addresses 0-3, which
have current level settings according to Table 2 and
Figure 2, Address 3 possesses a separate set of
current levels described by the Low Current
Backlight settings found in Table 3.
Data
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Main
Current On
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Sub
Current On
No
No
No
No
Yes
Yes
Yes
Yes
No
No
No
No
Yes
Yes
Yes
Yes
Current
(µA)
0
0
0
0
95
500
950
1900
95
500
950
1900
95
500
950
1900
Table 3: Data Code for Low-Level Backlight
Current, Address 3, FS = 20mA range.
2846.2007.08.1.0
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