Figure 5: LMR1 footpint (top view)
Pin description – LMR1
Pin
1a
Name
Vcc
Function
3.1 – 15V power supply
2a
0V
Ground
3a
4a
5a
RXE
RXD
AF out
Receiver Enable (active high)
Data out (open collector, no pullup)
700mV p-p audio. DC coupled, approx 0.8v bias.`
1b
P0/PGM
Parallel Channel select LSB
Serial frequency programming / configuration1
Parallel Channel select
2b
3b
4b
5b
P1
P2
P3
RSSI
Parallel Channel select
Parallel Channel select MSB
DC level between 0.5v and 2.2v. 60dB dynamic range
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. All pins are on an 0.1" grid
5. Data recovery circuit used for RXD is not a simple 'average and compare' type. It is a peak
sampling quasi-DC coupled design, allowing a greater than usual flexibility in data format.
6. Unit will operate (with marginally reduced specifications) 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.
Radiometrix Ltd
LMT1/LMR1 Data Sheet
page 5
RADIOMETRIX [ RADIOMETRIX LTD ]
