X7000 Datasheet, PDF (6/9 Pages) rfsolutions.ltd – 458MHZ RF SYNTHESISED TRANSCEIVER

458MHZ RF SYNTHESISED TRANSCEIVER
X7000
RST
RXON
FCNT
FDIR
MUX1/MUX2
The RST input when held low will reset the internal microprocessor.
The RXON input is used in conjunction with the TXON input to switch the module into
the receive mode, the transmit mode or the standby mode in the following way:
TXON RXON FUNCTION
Low Low Transmit
High Low Receive
Low High Transmit
High High Power Down
The FCNT input is used in conjunction with the FDIR input to increment or
decrement the RF channel by means of an external switch closure. The input has
internal switch debounce and a transition from high to low will cause the RF channel
to change.
The FDIR input sets the direction in which the RF channel will change. If FDIR is
high then when FCNT is changed from high to low the RF channel will be
incremented. If FDIR is low then when FCNT is changed from high to low the RF
channel will be decremented.
MUX1 and MUX2 are used to connect one of the three data inputs to the transmitter
in the following way:
MUX1 MUX2 INPUT
High High DIN
Low High AIN
High Low MIN
AIN
RDY
TRD
The AIN input accepts analogue modulation data. A 1Vp-p signal will cause
maximum frequency deviation of +/- 3kHz. The Input has a bandwidth of 6Hz to
5KHz with an input Impedance of 3kΩ.
The RDY output is set low when the synthesiser has locked. In the transmit mode
RDY can be used to give an indication that the module is ready to transmit data. If
the module is switched on or from the standby mode to the receive mode, RDY can
be used to indicate that the receiver is operational.
The TRD output is set high when the module is in the transmit mode or the receive
mode
+VE
CD
The +VE input is the second of two directly connected supply inputs. A regulated
8.5V to 14V power supply capable of supplying the following current:
Transmit Mode 350mA (inrush Current = 700mA for 20msec.)
Receive Mode 70mA
Standby Mode 2mA
The power supply should have a ripple voltage of <50mV on load. Some switch
mode power supplies can produce RF frequencies which will cause interference to
the receiver signal.
The CD output is set high when the receiver detects an RF carrier. The threshold is
factory set to 2µV but this can be adjusted to be more or less sensitive by a
potentiometer on the underside of the module.
NOTE:
All digital inputs are pulled up via 100kΩ resistors. They should not be connected
directly to the power rail
DS007_2
Oct 00
©2000 REG No 277 4001, ENGLAND.
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