FM TRANSMITTER & RECEIVER
MODULES. (2ND GENERATION)
FM-TX2-XXX
FM-RX2-XXX
Functional description:
The TX2 transmitter module is a two stage, SAW controlled FM transmitter operating between
2V and 6V and is available in 433.92MHz and 418.00 MHz versions. The 433.92 MHz unit is
type-approved to ETS 300-220 for European use and delivers nominally +9dBm from a 5V
supply at 12mA, while the 418.00 MHz unit has MPT 1340 type-approval for U.K. use and
delivers -3dBm from a 5V supply at 5mA. Both modules measure 12 x 32 x 3.8 mm.
The RX2 module is a double conversion FM superhet receiver capable of handling date rates of
upto 40kbit/s. The SIL style RX2 receiver measures 17.5 x 48 x 4.5 mm. It will operate from a
supply of 3-6V and draws 14mA when receiving. A fast-acting carrier detect and a power-up
enable time of less than 1ms This allows effective duty cycle power saving and a -107 dBm
sensitivity. This, combined with a SAW front-end filter results in an excellent RF performance
and EMC conformance.
TX2 transmitter:
fig. 1: TX2 block diagram
Pin description:
RF GND
(pin 1)
RF ground pin, internally connected to
the module screen and pin 4 (0V). This
pin should be connected to the RF
return path (e.g. coax braid, main PCB
ground plane etc.)
RF out
(pin 2)
50W RF output to the antenna, it is DC
isolated internally. (see antenna section
of TX2 applications note for suggested
antenna/feeds).
Vcc
(pin 3)
+ve supply pin. The module will generate RF when the Vcc supply is present. Max ripple
content 0.1VP-P. A 100nF de-coupling ceramic capacitor is suggested.
0V
(pin 4)
Supply ground connection, connected to pin 1 and screen.
TXD
(pin 5)
This DC coupled modulation input will accept either serial digital data ( 0V to Vcc levels) or
high level linear signals. see TX2 applications note for suggested drive methods. Input
impedance is 100kW.
DS000022
Rev D July ‘99
Ó1999 REG No 277 4001, ENGLAND.
Page 2
RFSOLUTIONS [ RFSOLUTIONS.LTD ]
