Figure 3: LMT2 footpint (top view)
Pin description – LMT2
Pin
Name
Function
1a
Vcc
3.1 – 15V power supply (@ 10mW)
4.1 – 15V power supply (@ 100mW)
Ground
Transmit Enable (active low)
DC coupled input for 3V CMOS logic. Rin=47kΩ
Not present in LMT2
2a
3a
4a
5a
0V
TXE
TXD
No pin
1b
P0/PGM
Parallel Channel select LSB
Serial frequency programming / configuration1
Parallel Channel select
Parallel Channel select
Parallel Channel select MSB
Not present in LMT2
2b
3b
4b
5b
P1
P2
P3
No pin
Notes:
1. Serial programming is by an inverted, CMOS logic level, 2400 baud RS232 datastream applied
to the P0 pin.
2. Channel select inputs have pullups (50kΩ) to 3v internal rail. Do not exceed 3V logic levels on
this port.
3. Channel select inputs are active low
4. TXE has a 100kΩ pullup to Vcc
5. All pins are on an 0.1" grid
6. The pins 5a/b are not present, but are included in footprint for compatibility with other units in
this family
7. In the 'off' state a PIN switch open circuits the RF output pin. There are no 'off' state spuri.
8. 10mW unit will operate (with marginally reduced specifications and lower (6-8mW) output
power) from a 3.0V rail. This must be well regulated and without noise or ripple, as in this state
the unit's internal regulator no longer operates, and provides no supply rejection.
9. 100mW versions should not be run continuously from supply voltages > 9v
Radiometrix Ltd
LMT2/LMR2 Data Sheet
page 3