7-4
SAMA5D3x-EK User Guide
11180A–ATARM–30-Jan-13
7.1.4
Back Light
The back light voltage is generated from a CP2122ST/CP2123ST boost converter. It is powered directly
by the DC 5V from the EK board. The back light level is controlled by a PWM signal generated from the
SAMA5D3 series processor.
Figure 7-4.
DM Back Light Control
7.1.5
QTouch
The 5-0_WVGA_R_AEA-DM board carries a QTouch device piloted through a TWI interface. It manages
four capacitive touch buttons directly printed on the PCB.
There is dual footprint for QTouch device, SOIC is the default mounted one.
Figure 7-5.
DM QTouch
2*20mA, 24.5V
2 x 7 LEDs Back Light
300mV
50V
A
m
0
4
/
V
5
.
4
2
A
m
7
1
2
/
V
5
60V/1A
880mA
10V
VLED-
VLED+
LCDPWM
5V_INTER
D1
RB160M-60
C7
10u
R41
7R5
L1
22uH
R40
10k
MN1
CP2122ST
SW
1
GND
2
FB
3
SHDN#
4
VIN
5
C9
2.2u
CHANGE#
TWD0
KEY4
KEY3
KEY2
KEY1
TWCK0
RESET#
TWD0
RESET#
CHANGE#
TWCK0
3V3_LCD
3V3_LCD
3V3_LCD
C14
100n
MN5
QT1070_SOIC
VDD
1
MODE(VSS)
2
SDA
3
RESET
4
CHANGE
5
SCL
6
KEY6
7
KEY5
8
KEY4
9
KEY3
10
KEY2
11
KEY1
12
KEY0
13
VSS
14
C16
100n
R57
4.7k
DNP
R62
4.7k
DNP
K4
KEY
R59
4.7k
DNP
MN4
QT1070
DNP
NC4
7
NC3
10
NC2
18
NC1
19
NC0
20
SDA
12
CHANGE
14
RESET
13
NC5
6
SCL
15
KEY4
1
KEY3
2
KEY2
3
KEY1
4
KEY0
5
VDD
9
MODE(
VSS)
11
VSS
8
KEY6
16
KEY5
17
Therm
al
21
R61
4.7k
DNP
K2
KEY
R56
4.7k
R58
4.7k
DNP
R68
4.7k
R65
4.7k
R66
4.7k
R67
4.7k
R60
4.7k
DNP
R63
10k
K3
KEY
K1
KEY
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