QM Receiver Module
QMR1 / QMR2
QMR2 Details
General Information
Antenna
Band Pass
Filter
Low Pass
Filter
Detector
Mixer
QMR2
RF
IF
AMP
AMP
Phase
Lock
Loop
1
2
3
4
5
6
7
Figure 3 QMR2 Receiver
Figure 4: Receiver Block Diagram
The QMR2 receiver module is a FM single
conversion superhet receiver capable of handling
data rates of up to 10Kbits/s. With an on board
data buffer, phase locked loop and a high quality
front end RF stage, a –107dBm sensitivity is
achieved.
Pin Description:
RF IN ( pin 1 )
50 ohm RF input from antenna, connect using
shortest possible route. This input is isolated from
the internal circuit using the air gap of the front
end SAW RF filter.
Utilising the latest phase locked loop receiver
technology with one of the compatible transmitter
modules will yield a highly efficient wireless link.
RF GND ( pin 2 )
Supply ground connection. Preferably connected
to a solid ground plane.
RSSI Values
RSSI ( pin 3 )
This is a dc output voltage that is proportional to
the RF signal strength applied to pin 1.
RF Level (dBm) pin 3
RSSI (volts) pin 6
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
1.16
1.34
1.59
1.78
1.81
1.81
2.17
2.45
2.52
2.52
2.52
GND ( pin 4 )
Connected to power supply ground.
Vcc ( pin 5 )
+Ve supply pin. Operation from a 5V supply able
to source 6mA at less than Vp-p ripple.
AF ( pin 6 )
Audio frequency output. Note Source current is
limited to 40 microA. In most applications a buffer
may be required to interface to this pin.
DATA OUT ( pin 7 )
CMOS compatible output. This may be used to
drive external decoders.
Ds302_3
AUG 01
Ó 2001 REG No 277 4001 England
Page 4
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