AAT2845
Four-Channel Backlight Driver with Dual LDOs
Evaluation Board Layout
Figure 3: AAT2845 Evaluation Board
Top Layer.
Figure 4: AAT2845 Evaluation Board
Bottom Layer.
microcontroller and apply external enable signals.
By removing the jumpers from J2, and/or J3, exter-
nal enable signals can be applied to the board.
External enable signals must be applied to the ON
pin of each J2, or J3 terminal.
Evaluation Board User Interface
The user interface for the AAT2845 evaluation
board is provided by three buttons and two connec-
tion 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.
When applying external enable signals, considera-
tion must be given to the voltage levels. The exter-
nally applied voltages should not exceed the sup-
ply voltage that is applied to the IN pins of the
device (DC+).
To power-on the evaluation board, connect a
power supply or battery to the DC- and DC+ termi-
nals. Close the board's supply connection by posi-
tioning the J1 jumper to the ON position. A red LED
indicates that power is applied.
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.
The evaluation board is made flexible so that the
user can disconnect the enable lines from the
Button(s) Pushed1
Description
DATA
Increment the backlight data setting. Hold down the button to auto-cycle through
the brightness levels.
LIGHT
Toggle ON/OFF the backlighting section. Set the brightness level using the DATA
button.
LIGHT+DATA
ENLDO
Decrement the backlight data setting. Hold down to auto-cycle.
Toggle ON/OFF the LDOs.
DATA+LIGHT+ENLDO
Reset. Clear data and bring all enable lines low.
Table 3: Evaluation Board User Interface.
1. The "+" indicates that these buttons are pressed and released together.
2845.2006.12.1.0
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