RX2A Datasheet, PDF (2/7 Pages) Radiometrix Ltd – UHF FM receiver module with RSSI

1
RF in
LNA 1
2
RF gnd
433MHz
SAW BPF
LNA 2
MIXER
IF1
10.7MHz
(f_RF - 10.7MHz)
10.7MHz IF filter
IF2/Lim
10.7MHz
Audio LPF
16
XTAL OSC.
VCO
Crystal
26/28MHz
Phase
detector
Loop filter
(Fixed frequency PLL Osc.)
+2.8V
regulated
to circuit
C_L
R_T
C_T
Low
dropout
regulator
Figure 2: RX2A Block diagram
AF
buffer
data
slicer
3
RSSI
10.7MHz
ceramic
discriminator
6
AF out
7
RXD
10kΩ
5
V_cc
4
0V
Pin description
48 mm
4.5 mm
RF IN
(pin 1)
50Ω input from the antenna, DC
isolated
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.)
RX2A
Radiometrix
30.48 mm
12
3 4 56 7
7 holes of 0.7 mm dia. pin spacing 2.54mm
Figure 3: Physical dimensions
PCB level
1 = RF IN
2 = RF GND
3 = RSSI
4 = 0V
5 = Vcc
6 = AF out
7 = RXD
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