Operating instructions

1892 1344 - SX450G Transceiver Operator Guide v1.7 / Nov 2007 7
CONNECTIONS
The radio antenna connects via an MMCX 50O socket.
All other connections to the SX450GA transceiver are made via a 12-way connector PL1
and an 8-way connector PL2. These are single-in-line plugs which mate with the free-
issued connectors with flying leads.
All other connections to the SX450GC transceiver are made via a 21-way SIL PCB
connector, PL1.
SX450GA SX450GC NAME FUNCTION REMARKS
PL1-1 PL1-1 0V 0 volts common ground
PL1-2 PL1-2 STBY standby input LOW (<+0.6V) = transceiver enabled
HIGH (>+2.0V) = standby mode
(internal pull-up, 40K to +4V max)
PL1-3 PL1-3 HI/LO TX RF power select
input
>+2.0V = high power, <+0.8V = low power
(internal pull-down, 10K to 0V)
PL1-4 PL1-4 +Vin positive supply input +5.5 to +9.0 V input (-ve earth)
PL1-5 PL1-5
TXE
transmit enable input HIGH (>+2.0V) = receiver enabled
LOW (<+0.8V) = transmitter enabled
(internal pull-up, 100K to +5V)
PL1-6 PL1-6 TXD/MS TXD - serial data
input
MS - mode select,
i.e. channel
selection by
serial or
parallel data
input
Serial data input = single 8-bit RS232 format
control word,
ie logic 1 = -V, logic 0 = +V (Maximum voltage
level is +12V; inverted TTL acceptable).
Mode selected depends on the logic state at any
time:
HIGH > 1ms (>+2.0V) = parallel data input.
Defaults to this state if left open circuit (internal
pull-up, 50K to +3V).
LOW (<+0.8V) = serial data input; connection to
an RS232 output will automatically keep it at this
state.
PL1-7 PL1-7 CS0/DT CS0 - channel
select input
(LSB)
DT - synthesizer
serial data
input*
Channel select inputs use inverted 5V logic
levels;
HIGH (>+2.0V) = logic 0, LOW (<+0.8V) = logic 1
CS0 to CS5 are used for channel selection by 6-
bit parallel data
(Internal pull-ups 100K to +5V)
(* DT/CK/EN inputs are used for direct control of
the synthesizer, this is a separate version of the
SX450.)
PL1-8 PL1-8 CS1/CK CS1 - channel
select input
CK - synthesizer
programme
clock *
PL1-9 PL1-9 CS2/EN CS2 - channel
select input
EN - synthesizer
enable strobe
input*
PL1-10 PL1-10 CS3 channel select input
PL1-11 PL1-11 CS4 channel select input