User guide

Evaluation Kit Hardware
4-80 Evaluation Kit (EK) User Guide
11115A–ATARM–27-Jul-11
4.4.3.3 Back Light
The back light voltage is generated from a CP2122ST 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 MPU
Device processor.
Figure 4-57. Back Light Control
4.4.3.4 QTouch
The DM board carries a QTouch device piloted through a TWI interface. It manages four capacitive
touch buttons directly printed on the PCB.
There are dual footprints for the QTouch device, and SOIC is the default mounted one.
Figure 4-58. QTouch
50V
5V/217mA 24.5V/40mA
10V
VLED-
VLED+
C9
2.2u
2 x 7 LEDs Back Light
2*20mA, 24.5V
5V_INTER
LCDPWM
C7
10u
300mV
L1
22uH
R41
7R5
R40
10k
MN1
CP2122ST
SW
1
GND
2
FB
3
SHDN#
4
VIN
5
D1
RB160M-60
60V/1A
880mA
TWD0
K2KEY
C14
100n
K3
KEY
K4
KEY
TWCK0
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
RESET#
R59 4.7k DNP
R65 4.7k
R66 4.7k
R56
4.7k
R67 4.7k
3V3_LCD
R68 4.7k
R57
4.7k
DNP
R60 4.7k DNP
R61 4.7k DNP
R58
4.7k
DNP
TWD0
R62 4.7k DNP
RESET#
3V3_LCD
CHANGE#
C16 100n
TWCK0
KEY4
KEY3
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
Thermal
21
KEY2
KEY1
K1
KEY
R63
10k
CHANGE#
3V3_LCD