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 2: 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)
PCB level
30.48 mm
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.)
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 3: Physical dimensions
RSSI
(pin 3)
Received signal strength indicator with 60dB range. See page 4 for typical characteristics.
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, RX2A Data Sheet
page 2
RADIOMETRIX [ RADIOMETRIX LTD ]
