Radiometrix Ltd., TX1 & RX1 Data Sheet

page 2

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

Lowpass filter

PA

Bandpass filter

x2

VCXO

7kHz LPF

100k

Supply

regulator

1

RF gnd

2

RF out

3

RF gnd

4

En

5

Vcc

6

0V

7

TXD

En

(pin 4)

Tx enable.

≤0.15V on this pin disables module (current <1µA), ≥1.7V enables module. Input impedance

1M

Ω approx. Observe slew rate requirements (see applications notes).

Vcc

(pin 5)

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 100k

Ω nominal.

Fig.2: TX1 physical dimensions

Pin description

RF gnd

(pins 1 & 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.

RF out

(pin 2)

50

Ω RF output to antenna. Internally

DC-isolated. See antenna section of

applications notes for details of suitable

antennas / feeds.

Fig.1: TX1 block diagram

3.8 mm

32 mm

12.0

mm

12.5

mm

PCB level

Radiometrix

TX1

pin spacing:

2.54 mm

7 holes of 0.7 mm dia. pin spacing 2.54 mm

15.24 mm

1

2

3

4

5

6

7

1 = RF gnd

2 = RF out

3 = RF gnd

4 = En

6 = 0V

7 = TXD

5 = Vcc