© Radiometrix Ltd

The BiM2 transceiver is an enhanced replacement for our original BiM. It offers greater transmit power, higher data rates, greatly improved receiver interference rejection and a lower profile.The module is ideal for enabling bi-directional wireless connectivity in battery powered or hand held applications. Figure 1: BiM2-433-160

Features CE Certified by independent Notified Body according to the R&TTE Directive (1999/5/EC) Verified to comply with Radio standard ETSI EN 300 220-3 by UKAS accredited Test Laboratory Verified to comply with EMC standard ETSI EN 301 489-3 by UKAS accredited Test Laboratory Usable range to 200 metres external, 50 metres in building Data rates up to160kbps SAW controlled 10mW FM transmitter Double conversion FM superhet receiver SAW front end filter and full screening Plug in replacement for Radiometrix BiM-433-30 3.3V or 5Volt supply at < 20mA

The BiM2 is a half duplex radio transceiver module for use in high-speed bi-directional data transfer applications at ranges up to 200metres. The module operates on the European licence exempt frequency of 433.92MHz and conforms to the relevant sections of EN 300 220-3 and EN 301 489-3. The small footprint of 23 x 33mm and low profile of 4mm together with low power requirements of <20mA @ 3 to 5 Volts enable convenient PCB installation. The high raw data rate capability of 64kbit/s and fast state change times will support high data throughput in ‘streaming’ applications or alternatively allows very short air time utilization (TX on < 10 ms) in multi-node scanning networks.

Applications PDA’s, organizers and laptops Handheld terminals EPOS equipment, barcode scanners, belt clip printers Data loggers Audience response systems In Building environmental monitoring and control High end security and fire alarms Restaurant ordering systems Vehicle data up/download

Technical Summary Size: 33 x 23 x 4mm Operating frequency: 433.92MHz Transmit power: 10dBm (10mW) nominal Supply: 5V, 3.3V Current consumption: 14mA transmit, 18mA receive Data bit rate: 64kbps max. (standard module) 64kbps, -93dBm sensitivity (for 1ppm BER)

Figure 2: BiM2 block diagram

Functional overview The transmit section of the BiM2 comprises of a SAW stabilized and FM modulated 433.92MHz oscillator feeding a 10mW buffer/output stage. Operation is controlled by a TX select line, the output achieving full power within 100ms of this line being pulled low. Modulation is applied at the TXD input and may be either a serial digital stream at the same levels as the module's supply rails (digital drive) or a high level analogue waveform with a pk to pk amplitude close to the modules supply level (linear drive). Modulation shaping is performed internally by a 2nd order 44kHz LPF to minimize spectral spreading. The RF output is filtered to meet the requirements of EN 300 220-3 and fed via a fast antenna changeover switch to the 50W antenna pin. The receive section of the BiM2 is a double conversion FM superhet with IF’s of 16MHz and 150kHz. The dual gate MOSFET LNA is followed by a 750kHz bandwidth SAW filter to provide >60 dB’s rejection of all out of band signals. The receiver is controlled by an active low select line and will power up in <1ms. A post-detection 2nd order 35kHz LPF establishes the signal bandwidth and ensures the clean operation of the subsequent adaptive data slicer. The slicer has a 2ms averaging time constant and is optimised for balanced data, e.g. bi-phase codes. A fast acting carrier detect output will indicate the presence of any RF signals

User interface Figure 3: BiM2 pin-out and dimension

Pin description: RF GND     pin 1 & 3 RF ground pin, internally connected to the module screen and pin 5, 9, 10, 18 (0 Volt). This pin should be connected to the RF return path (e.g. coax braid, main PCB ground plane etc.) Antenna      pin 2 50W RF input from the antenna, it is DC isolated internally. (see antenna for suggested antenna/feeds). 0Volt      pins 5, 9, 10, 18 Supply ground connection and screen. CD      pin 11 Carrier Detect - When the receiver is enabled, a low indicates a signal above the detection threshold is being received. The output is high impedance (50kW) and should only be used to drive a CMOS logic input. RXD      pin 12 This digital output from the internal data slicer is a squared version of the signal on pin 13 (AF). It may be used to drive external decoders. The data is true data, i.e. as fed to the transmitter.  Load impedance should be >1kW and <1nF AF    pin 13 This is a buffered and filtered analogue output from the FM demodulator. It has a standing DC bias of 1.2 volts and 400mV P-P base band signal. It is useful as a test point or to drive linear decoders. Load impedance should be >2kW and <100pF. TXD     pin 14 This DC coupled modulation input will accept either serial digital data (0V to Vcc levels) or High level linear signals. Input impedance is 10kW. TX select     pin 15 Active low transmit select. 10kW internal pull up to Vcc. RX select     pin 16 Active low receive select. 10kW internal pull up to Vcc. Pn 15 TX Pin16 RX Function 1 1 power down (<1mA) 1 0 receiver enabled 0 1 transmitter enabled 0 0 self test loop back Note: Loop test allows the receivers to monitor the transmitted signal. The receiver will not receive  external signals whilst the TX of the module is enabled. Vcc    pin 17 +ve supply pin.  +3.0 to +5.5 Volts @ <20mA . The supply must be clean < 20mVP-P ripple. A 2.2mF de-coupling capacitor and 10W series resistor are used internally to filter the supply.

Absolute maximum ratings Exceeding the values given below may cause permanent damage to the module. Operating temperature: -10°C to +60°C Extended operation at Reduced specification:  -20°C to + 70°C Storage temperature: -40°C to +100°C Vcc (pin 17): -0.1V to +10.0V Antenna (pin 2): ±50V @ <10MHz, +20dBm @ >10MHz All other pins: -0.1V to +Vcc + 0.6V Note: Operation of the BiM2 above 5.5 volt with efficient antenna may result in radiated power levels   above the licensed power level.  (Vcc = 5.0V / temperature = 20°C unless stated)

Electrical performance pin min. typ. max. units notes DC supply Supply voltage, Vcc (std. version) 17 4.0 5 5.5 V Supply voltage, Vcc (3V version) 17 3.3 3.3 4.0 V TX Supply current, Vcc (std.) 17 10 14 16 mV TX Supply current, Vcc(3.3V) 17 6 8 10 mA RX Supply current, Vcc (std.) 17 12 18 21 mA RX Supply current, Vcc (3.3V) 17 10 14 17 mA Supply ripple allowed 17 - - 20 mVpk-pk <1MHz Load capacitance on AF / RXD 12, 13 - - 100 pF CD output load resistnace 11 220 - - kW     Interface levels   data output high, 100mA source 12 - Vcc-0.6 - V RXD high data output low, 100mA sink 12 - 0.4 - V RXD low   TX & RX select, high (deselect 15, 16 Vcc-0.5 - Vcc V                              low (select) 15,16 0 - 0.5 V Intrenal selct pull-ups 15, 16 - 10 - kW              TXD, high 14 Vcc-0.5 Vcc V                        low 14 0 0.5 V   RF parameters pin min. typ. max. units notes Antenna pin impedance 2 - 50 - W TX or RX RF centre frequency - - 433.92 - MHz   Transmitter RF power output, Vcc std 2 +7 +10 +12 dBm 5V RF power output, Vcc 3.3V 2 +3 +6 +8 dBm 3.3V Initial frequency accuracy - -50 0 +50 kHz Overall frequency accuracy - -100 0 +100 kHz FM deviation (peak) - 20 30 40 kHz   Baseband Modulation bandwidth @ -3dB std - DC - 32 kHz Modulation bandwidth @ -3dB - DC - 80 kHZ 160kbps Modulation distortion (THD) - - - 15 %   Receiver RF/IF RF sensitivity @ 10dB SINAD 2, 13 -95 -101 - dBm RF sensitivity @ 10dB SINAD 2, 13 -91 -96 - dBm 3.3V RF sensitivity @ 10dB SINAD 2, 13 - -94 - dBm 160kbps RF sensitivity @ 1ppm BER 2, 12 -87 -93 - dBm 5V RF sensitivity @ 1ppm BER 2, 12 -82 -88 - dBm 3.3V RF sensitivity @ 1ppm BER 2, 12 - -90 - dBm 160kbps CD threshold, Vcc=5V 2, 11 -98 -104 - dBm note 2 CD threshold, Vcc=5V 2, 11 -92 -98 - dBm note 2 CD threshold, Vcc=5V 2, 11 - -96 - dBm note 2 IF bandwidth, Vcc=5V, 160kbps - - 500 - kHz CD bandwidth 2, 11 - 400 - kHz note 2 Ultimate (S+N)/N, -70dBm input 13 - >40 - dB Ultimate (S+N)/N, -70dBm input 13 - 30 - dB 160kbps maximum operating RF input 2 - +10 - dBm AF output level 13 - 400 - mV pk to pk DC offset on AF out 13 1.0 1.25 1.5 V Initial frequency accuracy - -50 0 +50 kHz CD centre     EMC parameters pin min. typ. max. units notes Rejection: rejection figures are relative to a 15dB (S+N)/N wanted signal. Co-channel rejection 2 - -10 - dB Image rejection (fRF - 2fIF) 2 - 64 - dB 402.0MHz Out of band rejection 2 - >70 - dB DC to 2GHz AM rejection 2 - >30 - dB Out of band blocking level 2 >-15 - dBm Out of band IP3 2 - +1 - dBm   Radiations LO leakage, conducted 2 - -60 -57 dBm   LO leakage, radiated - - -70 - dBm   TX 2nd harmonic 2 - -42 -36 dBm TX harmonics >1GHz 2 - -40 -30 dBm TX spectral bandwidth @ -40dBc 2 - - 250 kHz worst case   Baseband transfer performance pin min. typ. max. units notes TX—>RX Linear baseband BW @ -3dB 13 0.08 - 34 kHz TXD to AF Linear baseband BW @ -3dB, 160kbps 13 0.08 - 80 kHz TXD to AF Balance code bit rate 12 - 64 - kbps Time between code transitions 14 15.6 - 1000 ms Time between code transitions 14 15.6 - 120 ms 'S' version Time between code transitions 14 6.25 - 100 ms 160kbps Averaged code mark:space 14 30 50 70 % in any 2ms Preamble (01010101 pattern) duration 14 3 - - ms Link delay 14, 12 - 15 - ms   Dynamic timing Power up with signal present Power up to valid CD, tPU-CD 11 - 0.7 1 ms note 2 Power up to stable AF, tPU-AF 13 - 0.5 1 ms Power up to stable RXD output, tPU-RXD 12 - 3 5 ms Power up to stable RXD output, tPU-RXD 12 - - 1 ms 1, S version Power up to stable RXD output, tPU-RXD 12 - - 0.8 ms 160kbps   Signal applied with supply on Signal to valid CD, tsig-CD 11 - 0.25 0.5 ms note 2 Signal to stable RXD, tsig-RXD 12 - 3 4 ms Signal to stable RXD, tsig-RXD 12 - - 1 ms 1, S version Signal to stable RXD, tsig-RXD 12 - - 0.5 ms 160kbps   ms TX power up to full RF 2 - 100 -