RX2A receiver
3
433MHz
SAW BPF
10.7MHz IF filter
RSSI
MIXER
10.7MHz
ceramic
discriminator
IF2/Lim
10.7MHz
IF1
10.7MHz
LNA 2
LNA 1
1
RF in
Audio LPF
(fRF - 10.7MHz)
AF
buffer
6
AF out
CL
16
VCO
data
slicer
7
RXD
XTAL OSC.
RT
CT
10k
Ω
+2.8V
Low
Loop filter
regulated
to circuit
5
V
Crystal
26/28MHz detector
Phase
dropout
regulator
cc
(Fixed frequency PLL Osc.)
4
0V
2
RF gnd
Figure 4: RX2A Block diagram
48 mm
4.5 mm
Pin description:
RF IN
(pin 1)
50Ω input from the antenna, DC isolated
RX2A
Radiometrix
RF GND
(pin 2)
RF ground pin, internally connected to
the module screen and pin 4 (0V). This
pin should be connected to the RF return
path (coax braid, main PCB ground plane
etc.)
PCB level
30.48 mm
1 = RF IN
2 = RF GND
3 = RSSI
4 = 0V
1
2
3
4
5
6
7
5 = Vcc
6 = AF out
7 = RXD
7 holes of 0.7 mm dia. pin spacing 2.54mm
Figure 5: Physical dimensions
Received signal strength indicator with 60dB range. See page 4 for typical characteristics.
RSSI
(pin 3)
0V
(pin 4)
DC supply ground. Internally connected to pin 2 and module screen.
Vcc
(pin 5)
+2.7V to +16.0V DC supply. Max ripple content 0.1Vp-p. Decoupling is not generally required.
AF out(pin 6)
Buffered and filtered analogue output from the FM demodulator. Standing DC bias 1.1V approx. External
load should be >10k // <100pF.
RXD
(pin 7)
Digital output from the internal data slicer. The data is a squared version of the signal on pin 6 (AF) and
is true data, i.e. as fed to the transmitter. Output is “open-collector” format with internal 10k pull-up to
Vcc (pin 5).
Radiometrix Ltd, TX2A/RX2A Data Sheet
page 3
RADIOMETRIX [ RADIOMETRIX LTD ]
