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Apalis Carrier Board Design Guide
Toradex AG l Altsagenstrasse 5 l 6048 Horw l Switzerland l +41 41 500 48 00 l
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Page | 59
Figure 53: S/PDIF Reference Schematic
2.21.3 Unused S/PDIF Interface Signal Termination
Unused S/PDIF interface signals can be left unconnected.
2.22 Touch Panel Interface
The Apalis module standard features a touch panel interface for resistive touch screens. This allows
integrating touch screen solution with minimum amount of components on the carrier board. The
standard supports only four-wire resistive touch screens. Some modules may support five-wire
touch as well. Read the relevant datasheet of the module for more information.
2.22.1 Resistive Touch Signals
Apalis
Pin
Apalis
Signal Name
I/O
Type
Power
Rail
Description
315
AN1_TSPX
I/O
Analogue 3.3V
X+ (4-wire)
317
AN1_TSMX
I/O
Analogue 3.3V
X- (4-wire)
319
AN1_TSPY
I/O
Analogue 3.3V
Y+ (4-wire)
321
AN1_TSMY
I/O
Analogue 3.3V
Y- (4-wire)
Table 34: Digital Audio Signals
2.22.2 Reference Schematics
In order to reduce noise that is picked up by the display or long cables, it is recommended to add
capacitor to the touch screen signals. 1nF to 10nF is a good choice. It is also recommended to add
clamping diodes in order to protect the input of the touch screen controller against ESD.
Figure 54: Touch Interface Reference Schematic
MM70-314-310B1
Apalis - SPDIF
13 of 25
SPDIF1_OUT
215
SPDIF1_IN
217
X1M
GND
100pF
10V
C287
SPDIF1_OUT_OPT
PLT133/T9
GND
1
VCC
2
VIN
3
TX
X21
100nF
C313
GND
220R
R276
0R
R275
NA
NA
22R
RA26C
22R
RA26D
5V_SW
GND
GND
1
2
RCJ -047
X22
1
2
RCJ -047
X23
220R
R17
R18
120R
47nF
16V
C17
2A
220R@100MHz
L17
GND
0R
R16
NC
1
A
2
GND
3
Y
4
VCC
5
IC17
SN74LVC1G04DCKR
NC
1
A
2
GND
3
Y
4
VCC
5
IC18
SN74LVC1G04DCKR
GND
R19
75R
100nF
16V
C18
75R
R20
10k
R21
100nF
16V
C19
GND
GND
3.3V_SW
100nF
16V
C20
3.3V_SW
GND
Optical Out
Coax Out
Coax In
GND
1nF
50V
C103
1nF
50V
C100
1nF
50V
C101
1nF
50V
C102
TSW-103-07-G-D
1
2
3
4
5
6
X16
2.54mm Male
MM70-314-310B1
Apalis - Touch
9 of 25
AN1_TSPX
315
AN1_TSMX
317
AN1_TSPY
319
AN1_TSMY
321
X1I
AN1_TSPX
AN1_TSMX
AN1_TSPY
AN1_TSMY
AN1_TSPX
AN1_TSMX
AN1_TSPY
AN1_TSMY
RCLAMP0504S
1
2
3
4
5
6
D8
GND