BIM2A-433-64 RADIOMETRIX, BIM2A-433-64 Datasheet - Page 2

• Manufacturer Part Number: BIM2A-433-64
• Description: TRANSCEIVER, 433.92MHZ
• Manufacturer: RADIOMETRIX

Specifications of BIM2A-433-64

• Rohs Compliant: YES

Functional overview
The transmit section of the BiM2A consists of a frequency modulated crystal locked PLL feeding a
buffer amplifier and RF filter. A TX select line controls operation. The transmitter achieves full RF
output typically within 1ms of this line being pulled low. Modulation is applied at the TXD input and
may be either a serial digital stream toggling between 0V and 3V (digital drive) or a high level analogue
waveform with the same peak limits (linear drive). Modulation shaping is performed internally by a 2nd
order lowpass filter which minimises spectral spreading. The RF output is filtered to ensure compliance
with the appropriate regulations and fed via a Tx/Rx changeover switch to the antenna pin.
The receive section is a single conversion FM superhet with an IF of 10.7MHz. A SAW bandpass filter in
the receiver front-end provides image rejection and suppression of other unwanted out-of-band signals.
Like the transmitter, the receiver is controlled by its own active low RX select line. A post-detection
lowpass filter establishes the signal bandwidth and ensures clean operation of the subsequent adaptive
data slicer. The slicer is optimised for balanced data such as bi-phase code. The standard module
features a received signal strength (RSSI) output with 60dB of range. A version of BiM2A featuring a
fast acting Carrier Detect (CD) output on the same RSSI pin is also available. The CD output will
indicate the presence of any RF signals on the carrier frequency.
Pin description
RF GND
RF ground pins, internally connected to the module screen and to pins 5, 9, 10 & 18 (0V). These pins
should be connected directly to the RF return path (e.g. coax braid, main PCB ground plane etc).
Antenna
50
feeds.
0V (GND)
Supply ground connection and screen.
RSSI
Received Signal Strength Indicator with 60dB range, operational when Rx is enabled. Output voltage
nominally 0.17-0.33Vdc (no signal), 1.25Vdc (maximum). See page.8 for typical characteristics.
CD
Carrier Detect - When the receiver is enabled, a low indicates a signal above the detection threshold is
being received. The output is high impedance (50k ) and should only be used to drive a CMOS logic
input.
Radiometrix Ltd, BiM2A Data Sheet
Antenna
RF connection to the antenna, DC-isolated. See pages 7 & 8 for details of suitable antennas and
matching
& lpf
pins 1 & 3
pin 2
pins 5, 9, 10 & 18
pin 11
pin 11
preamp
Tx/Rx switch
PA
433MHz
bpf
V C O
Fig. 2: Block diagram
V C O
Mixer
32
Loop
Filter
IF Amp
Demod
10.7MHz
Loop
Filter
32
osc
ref
LPF
2.8V/3.3V
osc
ref
35kHz
LPF
Regulator
& Tx/Rx
slicer
data
logic
(3.7 - 16V for BiM2EH)
2.9 - 16V
TXD
Vcc
Tx select
Rx select
RSSI
RXD
CD/
AF
page 2