QM Receiver Module
QMR2 Details
QMR1 / QMR2
General Information
Antenna
QMR2
RF
AMP
Mixer
Band Pass
Filter
IF
AMP
Low Pass
Filter
Detector
1
2
3
4
5
6
7
Phase
Lock
Loop
Figure 3 QMR2 Receiver
Figure 4: Receiver Block Diagram
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.
RF GND ( pin 2 )
Supply ground connection. Preferably connected
to a solid ground plane.
RSSI ( pin 3 )
This is a dc output voltage that is proportional to
the RF signal strength applied to pin 1.
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.
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.
Utilising the latest phase locked loop receiver
technology with one of the compatible transmitter
modules will yield a highly efficient wireless link.
RSSI Values
RF Level (dBm) pin 3
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
RSSI (volts) pin 6
1.16
1.34
1.59
1.78
1.81
1.81
2.17
2.45
2.52
2.52
2.52
Ds302_3
AUG 01
©
2001 REG No 277 4001 England
Page 4
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