RX1 receiver
7
Vcc
Xtal osc/mult.
x2
Bandpass filter
Supply
regulator
Regulated
Rx supply
4
En
FM
discriminator
IF amplification / filtering
IF1
AF buffer
1
8
Bandpass filter
7kHz LPF
RF in
AF out
Preamp.
IF2
10k
Mixer
9
RXD
2
RF gnd
5
Adaptive
RSSI
data slicer
3
6
RF gnd
0V
Fig.3: RX1 block diagram
5.5 mm
48 mm
Pin description
RF in (pin 1)
50Ω RF input from antenna.
Internally DC-isolated. See
antenna section of applications
notes for suggested antennas and
feeds.
RX1
Radiometrix
pin spacing: 2.54 mm
25.4 mm
PCB level
1 = RF in
2 = RF gnd
3 = RF gnd
4 = En
5 = RSSI
6 = 0V
7 = Vcc
RF gnd
(pins 2 & 3)
RF ground, internally connected
to the module screen and pin 6
(0V). These pins should be
directly connected to the RF
return path - e.g. coax braid,
main PCB ground plane etc.
1
2
3
4
5
6
7
8
9
8 = AF out
9 = RXD
9 holes of 0.7 mm dia. pin spacing 2.54mm
Fig.4: RX1 physical dimensions
En
(pin 4)
Rx enable. ≤0.15V on this pin disables module (current <1µA), ≥1.7V enables module. Input impedance
1MΩ approx. Observe slew rate requirements (see applications notes).
RSSI
(pin 5)
Received Signal Strength Indicator with >80dB range. See applications notes for typical characteristics.
0V
(pin 6)
DC supply ground. Internally connected to pins 2, 3 and module screen.
Vcc
(pin 7)
DC +ve supply. Max ripple content 0.1VP-P. Decoupling is not generally required.
AF out
(pin 8)
Buffered and filtered analogue output from the FM demodulator. It has a standing DC bias of 1V and
400mVP-P baseband signal. Useful as a test point or to drive external decoders (see applications notes).
External load should be >1kΩ // <100pF.
RXD
(pin 9)
Digital output from internal data slicer (squared version of the signal on pin 8). It may be used to drive
external decoders. The data is true data, i.e. as fed to the transmitter. Output is “open-collector”
format with internal 10kΩ pullup to Vcc (pin 7).
Radiometrix Ltd., TX1 & RX1 Data Sheet
page 3
RADIOMETRIX [ RADIOMETRIX LTD ]
