Radiometrix Ltd, BIM2/3G Data Sheet

page 3

RXD

pin 12

Digital output from internal data slicer. The output is a squared version of the signal on pin 13 (AF) and may be

used to drive a decoder directly. The data is true data, i.e. as fed to the transmitter. Output is “open-collector”

format with internal 10k

Ω pullup to Vcc (pin 17).

AF

pin 13

Buffered & filtered analogue output from FM demodulator. Standing DC bias of 1V approx. Useful for test

purposes or for driving external decoders. External load should be >10k

Ω // <100pF

TXD

pin 14

This DC-coupled transmitter modulation input will accept either serial digital data or high level linear signals.

Drive signal must be limited to 0V min, 5V max. See page 7 for suggested drive methods. Input impedance

>50k

Ω.

TX select

pin 15

Active-low Transmit select. 47k

Ω internal pull-up to Vcc.

RX select

pin 16

Active-low Receive select. 47k

Ω internal pull-up to Vcc.

Pin 15 TX

Pin 16 RX

Function

1

1

Power down (<10

µA)

1

0

Receiver enabled

0

1

Transmitter enabled

0

0

Self test loop-back*

* Loop-back allows the receiver to monitor the transmitted signal. Under these conditions the Tx radiated signal

level will be reduced to approximately -10dBm).

Vcc

pin 17

+5V DC +ve supply pin. The supply should be clean, <20mVP-P ripple.