Figure 3: Provisional USX2 footprint
Pin Description
Pins
1A
2A
3A
1
2
3
4
5
6
7
8
9
10
11
Normal mode
RF Gnd
RF in/out
RF Gnd
TXD
TXE
GND
Vcc
P3
P2
P1
P0
RSSI
RXD
AF out
RF ground
To the antenna
RF ground
DC coupled input for TTL/ CMOS logic
Transmit enable.
Low = RX mode. High = TX. (10kΩ pull down)
(0V)
DC supply input (3.6 –15V)
Parallel channel select MSB
Parallel channel select
P1 - Parallel channel select
P0 - Parallel channel select LSB
DC level between 0.5V and 2.5V. 60dB dynamic
range
Open collector output of data slicer
500mV p-p audio. DC coupled, approx 0.8V bias
NC
NC
Serial mode
Modem
mode
Serial read back
TBA
TBA
PGM in
BUSY
MOD TXD
MOD RXD
PGM in
NC
NC
NOTES:
1.
2.
3.
4.
5.
6.
7.
8.
No inversion occurs between TXD and RXD. However AF out
is
inverted relative to TXD.
Parallel channel selects (P0-P3) and TXE are active LOW and have 47kΩ internal pullups to 3V
Open collector output RXD has a 47
kΩ
pullup to 3V.
The software incorporates a 1200 baud modem, compatible with that implemented in other
Radiometrix narrowband units ( i1200 tones and format ). Modem operation is selected by serial
command.
Main serial port (P0, P3) operates at 9600 baud. (Command set is not the same as TR2M, SMX
families). The unit is capable of operating in 'basic' parallel channel select only mode, or in serial
controlled 'expanded' mode
Transmit power can be set by serial command
RSSI can be read back as a digital value. (on P3)
If analogue transmit modulation is needed, then connect a series 1µF cap + 500kΩ trimmer (a
multiturn is advised) in the TXD circuit. Adjust trimmer for 90% of peak deviation (+/- 2.7KHz) at
mean input level.
Radiometrix Ltd
USX2 Data Sheet (preliminary)
page 3
RADIOMETRIX [ RADIOMETRIX LTD ]
