Radiometrix Ltd.,

NiM2 transceiver data sheet

Page 3

Functional description

The transmit section of the NiM2 consists of a frequency modulated Voltage Controlled Crystal

Oscillator (VCXO) feeding a frequency doubler with two stage amplifier and RF filter. Final Power

Amplifier stage is factory pre-set to appropriate band power level. Operation is controlled by a Tx Select

line, the transmitter achieving full RF output typically within 5ms of this line being pulled low. The RF

output is filtered to ensure compliance with the appropriate radio regulations and fed via a fast Tx/Rx

changeover switch to the 50

Ω antenna pin.

The receive section is a double conversion FM superhet with IF at 21.4MHz and 455kHz fed by a Low

Noise Amplifier (LNA) on the RF front-end. The receiver is controlled by RX Select line and will power

up typically <2ms. Quadrature detector output is available as Audio Frequency (AF) output and

transmitted digital data is regenerated from AF using adaptive data slicer. A Received Signal Strength

Indicator (RSSI) output with some 60dB of range is provided.

User interface

18

17

16

15

14

13

12

11

10

0 Volt

Vcc

RX select

TX select

TXD

AF

RXD

RSSI

0 Volt

1

2

3

4

5

6

7

8

9

RF GND

Antenna

RF GND

No pin

33 mm

30.48 mm

23 mm

12 mm

side view (through can)

top view (without can)

side view (with can)

recommended PCB hole size: 1.2 mm

module footprint size: 25 x 32 mm

pin pitch: 2.54 mm

pins 4, 5, 6, 7, 8 & 9 are not fitted

Figure 3: NiM2 pin-out and dimension

NiM2 Pin

Name

Function

1, 3, 10, 18

0V

Ground

17

VCC

2.9 – 15V DC power supply

16

RX

Pull low to enable Receiver

15

TX

Pull low to enable Transmitter

14

TXD

Ω

13

AF

12

RXD

RXD is an open collector output, with a 10k

11

RSSI

DC level between 0.5V and 2V. 60dB dynamic range

NOTES:

1. RX and TX have internal (10k

Ω approx.) pull-ups to Vcc

2. Avoid RX and TX both low: undefined module operation (but damage will not result)

3. Pin out is as BiM1, BiM2. On RF connector end only pins 1, 2 and 3 are present.