AAT2842INJ-EE-T1 Advanced Analog Technology, Inc., AAT2842INJ-EE-T1 Datasheet - Page 17

• Manufacturer Part Number: AAT2842INJ-EE-T1
• Description: High-Current Charge Pump with S2Cwire Control and Dual LDO for Backlight and Flash
• Manufacturer: Advanced Analog Technology, Inc.

Evaluation Board Schematics
1. The “+” indicates that these buttons are pressed and released together.
2842.2007.09.1.2
LIGHT+MOVIE+FLASH
Button(s) Pushed
MOVIE+DATA
DATA+FLASH
LIGHT+DATA
MOVIE
FLASH
LIGHT
DATA
CTRL _ CT
OUTB
280K yields 30mA/ch
max backlighting
280K yields 150mA/ch
max flash
R9
280K
1
Programmed for
2.8V output by default
R10
280K
1.0μF
C9
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).
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).
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.
Reset. Clear all data and bring all enable lines low.
Description
1.0μF
C8
Table 4: Evaluation Board User Interface.
Figure 4: AAT2842 Section Schematic.
R11
160K
R12
120K
Control and Dual LDO for Backlight and Flash
D1
1
2
3
4
5
6
7
C6
BL1
BSET
FSET
AGND
CT
REF
FBB
2.2μF
D2
High-Current Charge Pump with S
D3
D4
R13
60.4K
R14
120K
C1
1.0μF
VOUT
PGND
ENL
C2+
FL3
FL4
C2-
U1
AAT2842
IN
C7
2.2μF
21
20
19
18
17
16
15
D5
C3
2.2μF
VOUT
D6
C2
1.0μF
C5
2.2μF
C4
4.7μF
VIN
1.8V output by default
Programmed for
C12
100μF
optional 100μF
lab supply bypass
J1
3
OUTA
AAT2842
ENBL
ENFL
ENL
2
DC+
1
2
Cwire™
17