AAT2846
High Current Charge Pump with Dual LDO
for Backlight and Flash Applications
Button(s) Pushed
Description
DATA
Increment the data setting for the most recently activated mode. With backlight or
movie mode activated, hold down the button to auto-cycle through the brightness levels.
Toggle ON/OFF the backlighting section. Set the brightness level using the DATA button
(defaults to Data 1).
LIGHT
LIGHT+DATA
MOVIE
Decrement the brightness setting for backlight mode. Hold down to auto-cycle.
Toggle ON/OFF movie mode illumination. Set the brightness level using the DATA but-
ton (defaults to Data 10).
MOVIE+DATA
FLASH
Decrement the brightness setting for movie mode. Hold down to auto-cycle.
Generate a flash pulse. Pulse duration is the lesser of 2 seconds or the CT value result.
Set the brightness level using the DATA button (defaults to Data 1).
Toggle ON/OFF the LDOs.
FLASH+DATA
LIGHT+MOVIE+FLASH
Reset. Clear all data and bring all enable lines low.
Table 11: AAT2846 Evaluation Board User Interface.
Evaluation Board Schematics
VOUT
DC+
D1
D2
D3
D4
D5
D6
D7
D8
VIN
J1
C12
1
2
3
280K yields
300mA/chnl
max flash
100μF
optional 100μF
lab supply bypass
R10
280K
U1
ENLA
ENFL
1
2
3
4
5
6
7
21
20
19
18
17
16
15
D3
F2
ENBL
ENLB
D2
ENS
PGND
IN
D1
AGND
CT
C4
4.7μF
C2-
C2
1.0μF
CREF
FBB
C2+
ENB
C8
0.1μF
_
CTRL CT
C9
0.1μF
8
9
10 11 12 13 14
VOUT
C3
C6
R11
160K
OUTB
2.2μF
C5
2.2μF
C1
1.0μF
2.2μF
Programmed for 2.8V
output by default
R12
120K
OUTA
C7
2.2μF
R13
60.4K
Programmed for 1.8V
output by default
R14
120K
Figure 8: AAT2846 Section Schematic
2846.2007.08.1.0
21
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
