AAT2856 AAT, AAT2856 Datasheet - Page 17

• Manufacturer Part Number: AAT2856
• Description: High Current Charge Pump
• Manufacturer: AAT

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 combinations. The table below
indicates the function of each button or button
combination.
To power-on the board, connect a power supply or
battery to the DC- and DC+ terminals. Make the
board's supply connection by positioning the J1
jumper to the ON position. A red LED indicates that
power is applied.
Evaluation Board Layout
1. The enable for LDOA and LDOB are manually set externally.
2856.2007.06.1.0
Button(s) Pushed
Figure 7: AAT2856 Evaluation Board
SW1
SW2
SW3
Layout Top Side.
Table 14: AAT2856 Evaluation Board User Interface
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 cur-
rent is increased (brighter). If held down, auto-cycle through the settings.
[Push/Release once] Toggle between 20mA and 30mA maximum current.
Dual LDO for BacklightApplications
The Enables of both LDOs are connected with
jumpers J3 and J4. These terminals must be con-
nected to the external source to turn on/off the
LDOs.
When applying external enable signals, considera-
tion must be given to the voltage levels. The exter-
nally applied voltages cannot exceed the supply volt-
age that is applied to the IN pins of the device (DC+).
The LDO loads can be connected directly to the
evaluation board. For adequate performance, be
sure to connect the load between OUTA/OUTB and
DC- as opposed to some other GND in the system.
High Current Charge Pump with
Figure 8: AAT2856 Evaluation Board
Layout Bottom Side.
1
.
AAT2856
17