Linx Technologies TXM-xxx-LR - Manual (Page 9)

– – – – 12 13
Typical Applications
Figure 12 shows a circuit using a Linx MS Series encoder. This chip works
with the LICAL-DEC-MS001 decoder to provide simple remote control
capabilities. The decoder detects the transmission from the encoder,
checks for errors, and if everything is correct, replicates the encoder’s
inputs on its outputs. This makes registering key presses very simple.
The transmitter can also be connected to a GPIO of a microcontroller in
applications that use a custom protocol. No buffering is generally required
between the transmitter and microcontroller output. Exceptions to this
include systems where the microcontroller is operating at a different voltage
from the transmitter. In these cases the designer should take care to use
voltage translator circuits as appropriate.
2.7k
GND
1
DATA IN
2
GND
3
IADJ/VCC 4 RF OUT 5
GND
6
VCC
7
PDN
8
TXM-xxx-LR
100k
100k
220
100k
100k
100k
100k
100k
100k
100k
LICAL-ENC-MS001
D6
D7
SEL_BAUD0
SEL_BAUD1
GND
GND
GND
TX_CNTL
DATA_OUT
MODE_IND D5
D4
D3
D2
VCC
VCC
D1
D0
SEND
CREATE_ADDR
1
2
3
4
5
6
7
8
9
10 11
12
13
14
15
16
17
18
19
20
VCC
VCC DATA
DATA
ESD Concerns
The module has basic ESD protection built in, but in cases where the
antenna connection is exposed to the user it is a good idea to add
additional protection. A Transient Voltage Suppressor (TVS) diode, varistor
or similar component can be added to the antenna line. These should have
low capacitance and be designed for use on antennas. Protection on the
supply line is a good idea in designs that have a user-accessible power
port.
Figure 12: LR Transmitter and MS Encoder