Functional description
The TX1 module is a two stage crystal controlled NBFM transmitter operating between 2.2V and 12V
at a current of 9.5mA. At 3V supply it delivers nominally +10dBm RF output. The SIL style TX1
measures 32 x 12 x 3.8 mm excluding the pins.
The RX1 module is a single conversion NBFM superhet receiver capable of handling data rates of up to
10kbps. It will operate from a supply of 2.7V to 12V and draws 12mA when receiving. A signal strength
(RSSI) output with greater than 80dB of range is provided. The SIL style RX1 measures 48 x 17.5 x 5.5
mm excluding the pins.
TX1 transmitter
5
Vcc
Supply
regulator
4
En
VCXO
2
7
TXD
Bandpass filter
7kHz LPF
Lowpass filter
RF out
x2
PA
3
100k
RF gnd
1
6
RF gnd
0V
Fig.1: TX1 block diagram
3.8 mm
32 mm
Pin description
RF gnd (pins 1 & 3)
Radiometrix
12.0
mm
12.5
mm
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.
TX1
pin spacing:
2.54 mm
PCB level
15.24 mm
1 = RF gnd
2 = RF out
3 = RF gnd
4 = En
5 = Vcc
6 = 0V
7 = TXD
4
5
6
7
1
2
3
RF out
(pin 2)
50Ω RF output to antenna. Internally
DC-isolated. See antenna section of
applications notes for details of suitable
antennas / feeds.
7 holes of 0.7 mm dia. pin spacing 2.54 mm
Fig.2: TX1 physical dimensions
En
(pin 4)
Tx 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).
Vcc
(pin 5)
DC +ve supply. Max ripple content 0.1VP-P. Decoupling is not generally required.
0V
(pin 6)
DC supply ground. Internally connected to pins 1, 3 and module screen.
TXD
(pin 7)
DC-coupled modulation input. Accepts serial digital data at 0V to 3V levels.
See applications notes for suggested drive methods. Input impedance 100kΩ nominal.
Radiometrix Ltd., TX1 & RX1 Data Sheet
page 2