AAT2856INJ-EE-T1 Advanced Analog Technology, Inc., AAT2856INJ-EE-T1 Datasheet - Page 14

• Manufacturer Part Number: AAT2856INJ-EE-T1
• Description: High Current Charge Pump with Dual LDO for Backlight Applications
• Manufacturer: Advanced Analog Technology, Inc.

Evaluation Board User Interface
The user interface for the AAT2856 evaluation board is
provided through 4 buttons and a number of connection
terminals. The board is operated by supplying external
power and pressing individual buttons or button combi-
nations. The table below indicates the function of each
button or button combination.
To power-on the board, connect a power supply or bat-
tery to the DC- and DC+ terminals. Make the board’s
Evaluation Board Layout
1. The enable for LDOA and LDOB are manually set externally.
14
ChargePump
Figure 4: AAT2856 Evaluation Board
Figure 3: Example PCB Layout.
TM
Layout Top Side.
High Current Charge Pump with Dual LDO for Backlight Applications
w w w . a n a l o g i c t e c h . c o m
supply connection by positioning the J1 jumper to the
ON position. A red LED indicates that power is applied.
The Enables of both LDOs are connected with jumpers J3
and J4. These terminals must be connected to the exter-
nal source to turn on/off the LDOs.
When applying external enable signals, consideration
must be given to the voltage levels. The externally
applied voltages cannot exceed the supply voltage that
is applied to the IN pins of the device (DC+).
The LDO loads can be connected directly to the evalua-
tion board. For adequate performance, be sure to con-
nect the load between OUTA/OUTB and DC- as opposed
to some other GND in the system.
Table 9: AAT2856 Evaluation Board User Interface
Button(s)
Pushed
SW1
SW2
SW3
Figure 5: AAT2856 Evaluation Board
Description
[Push/Release once] Increment the number
of EN/SET edges, but the backlight current
is decreased (dimmer). If held down, auto-
cycle through the settings.
[Push/Release once] Decrement the number
of EN/SET edges, but the backlight current
is increased (brighter). If held down, auto-
cycle through the settings.
[Push/Release once] Toggle between 20mA
and 30mA maximum current.
Layout Bottom Side.
PRODUCT DATASHEET
AAT2856
2856.2008.02.1.3
1
.