Receivers, Typical applications – Linx Technologies CMD-KEY#-xxx User Manual
Page 4
VCC
GND
B1
TOUCHPAD
S
5
TOUCHPAD
S
4
TOUCHPAD
S3
TOUCHPAD
S
2
TOUCHPAD
S
1
VCC
VCC
CUT TRACE FOR
ADDRE
SS
S
ELECT
GND
3
90k
R4
GND
HT640
U1
24
VCC
2
3
D0
22
A9
21
A
8
20
A7
19
A6
1
8
A5
17
A4
16
A
3
15
A2
14
A1
1
3
A0
12
GND
11
O
S
C1
10
O
S
C2
9
TE
8
DOUT
7
D7
6
D6
5
D5
4
D4
3
D
3
2
D2
1
D1
VCC
VCC
GND
DATA IN
GND
IADJ/VCC
RF OUT
GND
VCC
PDN
TXM-LR
GND
GND
GND
R1
S
et For FCC
Compli
a
nce
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Page 7
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Figure 7: CMD-KEY#-*** Schematic Diagram
RECEIVERS
There are four options for receivers within the Linx
product line. The first option is to use one of the OEM
Function Modules, such as the Relay Module or the AC
Wall Module. These items are also pre-certified and
can be immediately included in a product.
The other options are to use one of the Linx receiver
modules. The signal sent by the Keyfob transmitter can
be received by the LR Series receiver module or the LT
Series transcever module. These modules can be
connected to the Holtek HT658 decoder to decode the
signal, or a custom microcontroller can be programmed
to decode it and take specific action.
The KH2 Series offers a slightly simpler solution by
combining the LR Series receiver and the HT658
decoder in a single package.
When a button is pressed on the transmitter, a
corresponding line on the decoder will go high (as long
as the addresses match). This can then be connected
to whatever circuitry is required by the application.
Application Note AN-00300 discusses in detail how to
set the addresses on all of the units. Data guides for all
of the receivers, the HT640 encoder, and the HT658
decoder can be found on the Linx Technologies
website, www.linxtechnologies.com.
TYPICAL APPLICATIONS
The outstanding sensitivity of the LR
Series receiver offers the best range
when combined with the Keyfob
transmitter. When using the LR
Series receiver, the Holtek HT658
decoder chip should be connected
to decode the received signal. This
decoder has ten address lines that
must match the Keyfob address
lines. A DIP switch is commonly
used to set these, but they can also
be hardwired. As long as the
address lines match, when a button
on the Keyfob is pressed, a
corresponding data line on the
decoder (D0-D4) will go high. These
data lines can then be connected to
external circuitry to perform
whatever function is required by the
application.
GND
R1
390k
GND
GND
VCC
VCC
D1
1
D2
2
D3
3
D4
4
D5
5
D6
6
D7
7
VT
8
DIN
9
OSC1
10
OSC2
11
GND
12
A0
13
A1
14
A2
15
A3
16
A4
17
A5
18
A6
19
A7
20
A8
21
A9
22
D0
23
VCC
24
HT658
NC
1
NC
2
NC
3
GND
4
VCC
5
PDN
6
RSSI
7
DATA
8
NC
9
NC
10
NC
11
NC
12
NC
13
NC
14
GND
15
ANT
16
RXM-LR
GND
Figure 6: LR Receiver and HT658 Schematic