Hartcran House, 231 Kenton Lane, Harrow, Middlesex, HA3 8RP, England Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233, www.radiometrix.com BiM2/BiM3G PRELIMINARY Issue 1, 11 November 2009 433 / 868MHz FM Data Transceiver The BIM2/3G data radio module is a PLL synthesiser based miniature PCB mounting UHF radio transceiver which enable the simple implementation of a wireless data link at up to 128 kbps at distances up to 75 metres in-building and 300 metres open ground. Features ! ! ! ! ! ! Data rates up to 128 kbps Figure 1: BIM3G-869-64-5V Usable range up to 300 m Versions available on 433.92MHz, 434.42MHz and 868MHz band Fully screened Low profile with small footprint Designed for compliance with EN 300 220-3 (radio) and EN 301 489-3 (EMC) standards Available for operation at 433.92MHz, 434.42MHz and 868MHz band in the UK and Europe, these modules combine full screening with extensive internal filtering to ensure EMC compliance by minimising spurious radiations and susceptibilities. The BIM2/3G module will suit one-to-one and multi-node wireless links in applications. Because of their small size and low power requirements, the module is ideal for use in portable, battery-powered applications such as hand-held terminals. Applications ! ! ! ! ! ! ! Data loggers EPOS equipment, barcode scanners, belt clip printers Audience response systems In-building environmental monitoring and control Security and fire alarms Restaurant ordering systems Vehicle data up/download Technical Summary ! ! ! ! ! ! ! ! ! ! ! ! Crystal-locked PLL, FM modulated at up to 128 Kbps +10dBm on 433.92MHz and 868MHz (Dependent on version) High efficiency, >30%, DC to RF 2nd harmonic, > -60dBc Single conversion FM superhet receiver SAW front end filter gives >50dB image rejection Sensitivity: -102dBm sensitivity @ 1ppm BER, 64kbps version -108dBm sensitivity @ 1ppm BER, 15kbps version TBA dBm sensitivity @ 1ppm BER, 128kbps version RSSI output with 60dB range Extremely low LO leakage, -125dBm typical Supply: +5V (± 10%) Current consumption: 10mA (typ.) Size: 33 x 23 x 5mm Evaluation platforms: Universal Evaluation Kit, NBEK + DIL carrier Radiometrix Ltd, BIM2/3G Data Sheet page 1 Functional overview The transmit section of the BiM2/3G 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 5V (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. A received signal strength (RSSI) output with 60dB of range is provided. A version of BiM2/3G 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. side view (through can) side view (with can) 5 mm top view (without can) RF GND 1 Antenna 2 RF GND 3 4 5 No pin 6 7 8 0V 9 18 0V 17 Vcc 16 RX SELECT 15 TX SELECT 14 TXD 13 AF 12 RXD 11 RSSI/CD 10 0V 30.48 mm 33 mm 23 mm recommended PCB hole size: 1.2 mm module footprint size: 25 x 32 mm pin pitch: 2.54 mm (0.1") pins 4, 5, 6, 7 & 8 are not fitted Fig. 2: Physical dimensions Pin description RF GND pins 1 & 3 RF ground pins, internally connected to the module screen and to pins 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 pin 2 50Ω RF connection to the antenna, DC-isolated. See pages 7 & 8 for details of suitable antennas and feeds. 0V (GND) pins 9, 10 & 18 Supply ground connection and screen. RSSI /CD pin 11 RSSI variant: Received Signal Strength Indicator with 60dB range, operational when Rx is enabled. Output voltage nominally 0.50Vdc (no signal), 1.0Vdc (maximum strength). See page.6 for typical characteristics. Carrier Detect variant: When the receiver is enabled, a low indicates a signal above the detection threshold is being received. The output is high impedance and should only be used to drive a CMOS logic input. Radiometrix Ltd, BIM2/3G Data Sheet page 2 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 10kΩ 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 >10kΩ // <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 >50kΩ. TX select pin 15 Active-low Transmit select. 47kΩ internal pull-up to Vcc. RX select pin 16 Active-low Receive select. 47kΩ internal pull-up to Vcc. Pin 15 TX Pin 16 RX Function 1 1 Power down (<10µA) 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. Radiometrix Ltd, BIM2/3G Data Sheet page 3 Absolute maximum ratings Exceeding the values below may cause permanent damage to the module. Operating temperature -20°C to +70°C Storage temperature -40°C to +100°C Vcc (pin 17) -0.3V to +16V(Dependant on version) TX, RX select (pins 15, 16) -9V to +5.5V All other pins -0.3V to +Vcc Antenna (pin 2) ±50V DC, +10dBm RF Performance specifications Figures apply to standard version @ Vcc=5.0V, temperature +20°C, unless stated. pin 17 17 min. 4.5 - typ. 5.0 14 max. 5.5 - units V mA notes Note 9 Note 9 17 2 15, 16 15, 16 15,16 12 12 12 10 Vcc-0.5 0 - 11 mA MHz Ω V V kΩ kbps kbps kbps Note 1 Note 9 Tx or Rx 47 - 17 Vcc 0.5 128 64 15 To Vcc (pin 17) -128 version -64 version -15 version Transmitter section RF power output pin 2 min. - typ. +10 max. - units dBm notes Note 9 TX harmonics/spurious emission Initial centre frequency accuracy FM deviation Modulation bandwidth Modulation distortion TX spectral bandwidth @-40dBc TXD input level: high low TX power up to full RF 2 2 14 14 2 -10 ±20 0 2.8 0 - -55 0 ±27 5 5 1 -40 +10 ±35 65 10 250 0.2 1.5 dBm kHz kHz kHz % kHz V V ms Peak @ -3db Note 2 worst case Note 3 Note 3 Note 4 Receiver section RF sensitivity, 10dB S/N RF sensitivity, 1ppm BER RF sensitivity, 1ppm BER RF sensitivity, 1ppm BER pin 2, 13 2, 12 2, 12 2, 12 min. - typ. -113 -TBA -102 -108 max. - units dBm dBm dBm dBm -128 version -64 version -15 version RSSI range IF bandwidth Image rejection (fRF-21.4MHz) IF rejection (10.7MHz) Local osc. leakage, conducted Baseband bandwidth @ -3dB Baseband bandwidth @ -3dB Baseband bandwidth @ -3dB AF output signal level DC offset on AF output Distortion on recovered AF 2, 11 2 2 2 13 13 13 13 13 13 50 100 0 0 0 200 1.5 - 60 180 54 -125 250 2.0 1 -110 65 50 7.8 350 2.5 5 dB kHz dB dB dBm kHz kHz kHz mV p-p V % -128 version -64 version -15 version Note 5 Note 6 Note 7 Load capacitance, AF & RXD 12, 13 - - 100 pF General Supply voltage Tx supply current Rx supply current RF centre frequency Antenna port impedance TX & RX select: high (deselect) low (select) Internal select pull-ups Balanced code bit rate Balanced code bit rate Balanced code bit rate Radiometrix Ltd, BIM2/3G Data Sheet 50 notes page 4 Receiver section pin min. typ. max. units notes Dynamic Timing Rx power up with signal present Power up to valid RSSI, tPU-RSSI Power up to stable data, tPU-data Power up to stable data, tPU-data 11 12 12 - 0.5 2 2 1 10 10 ms ms ms -15 version -64 version Signal applied with Rx on RSSI response time (rise/fall) Signal to stable data, tsig-data Signal to stable data, tsig-data 11 12 12 - 100 0.5 0.2 1 0.5 µs ms ms -15 version -64 version Time between data transitions Time between data transitions Averaged code mark:space 14 14 14 70 15.6 20 50 5000 1500 80 µs µs % -15 version -64 version Note 8 Note: 1. Increases at high RF input level (>-20dBm) 2. See page 6 for further details 3. For specified FM deviation 4. Tx select low > full RF output 5. ±30kHz FM deviation –15 and –64 versions on;y 6. Min/max at ±50kHz offset 7. Max at ±50kHz offset 8. Average, at max. data rate 9. Dependant on version Power supply requirement The power supply ripple/noise should be below 10mVp-p to avoid problems. If the quality of the supply is in doubt, it is recommended that a 10µF low-ESR tantalum or similar capacitor be added between the module supply pin (Vcc) and ground, together with a 10Ω series feed resistor between the Vcc pin and the supply rail. The BIM2/3G incorporates a low voltage shutoff circuit, which prevents any possibility of erratic operation by disabling the RF output of the transmitter if the supply voltage drops below 2.2V (±5%). This feature is selfresetting, i.e. restoring the supply to greater than 2.2V will immediately restore full RF output from the module. The standard BiM2/3G requires a regulated 5V supply with ripple content <100mVpk-pk. Received Signal Strength Indicator (RSSI) The BIM2/3G module incorporates a wide range RSSI which measures the strength of an incoming signal over a range of approximately 60dB. This allows assessment of link quality and available margin and is useful when performing range tests. Please note that the actual RSSI voltage at any given RF input level varies somewhat between units. The RSSI facility is intended as a relative indicator only - it is not designed to be, or suitable as, an accurate and repeatable measure of absolute signal level or transmitter-receiver distance. The output on pin 5 of the module has a standing DC bias in the region of 0.5V with no signal, rising to around 1V at maximum indication. The RSSI output source impedance is high (~100kΩ) and external loading should therefore be kept to a minimum. To ensure a fast response the RSSI has limited internal decoupling of 1nF to ground. This may result in a small amount of ripple on the DC output at pin 5 of the module. If this is a problem further decoupling may be added at the expense of response speed, in the form of a capacitor from pin 5 to ground. For example, adding 10nF here will increase RSSI response time from 100µs to around 1ms. The value of this capacitor may be increased without limit. Radiometrix Ltd, BIM2/3G Data Sheet page 5 Typical RSSI characteristic is shown below (this is for indicative purposes only and is not a guarantee of actual RSSI characteristics): 1100 1000 RSSI VOLTAGE 900 800 700 600 500 400 300 200 -130 -120 -110 -100 -90 -80 -70 -60 -50 RF input level (dBm) Figure 3: Typical RSSI Module mounting considerations Good RF layout practice should be observed – in particular, any ground return required by the antenna or feed should be connected directly to the RF GND pin at the antenna end of the module, and not to the OV pin which is intended as a DC ground only. All connecting tracks should be kept as short as possible to avoid any problems with stray RF pickup. If the connection between module and antenna does not form part of the antenna itself, it should be made using 50Ω microstrip line or coax or a combination of both. It is desirable (but not essential) to fill all unused PCB area around the module with ground plane. The module may be potted if required in a viscous compound which cannot enter the screen can. Warning: DO NOT wash the module. It is not hermetically sealed. Radiometrix Ltd, BIM2/3G Data Sheet page 6 Application Information Modulation formats and range extension The module will produce the specified FM deviation with a 2-level digital input to TXD which toggles between 0V and 5V. Reducing the amplitude of the data input from this value reduces the transmitted FM deviation, typically to ±20-22kHz minimum at 0 - 2.8V. The receiver will cope with this quite happily and no significant degradation of link performance should be observed. TXD is normally driven directly by logic levels but will also accept analogue drive, e.g. 2-tone signalling. In this case it is recommended that TXD (pin 14) should be DC-biased to 1.5V with the modulation AC-coupled and limited to a maximum of 3V peak-to-peak. The instantaneous modulation voltage must not swing below 0V or above 3V at any time if waveform distortion and excessive FM deviation is to be avoided – use a resistive potential divider and/or level shifter to accomplish this if necessary. The varactor modulator in the transmitter introduces some 2nd harmonic distortion which may be reduced if necessary by predistortion of the analogue waveform. At the other end of the link the AF output (pin 13) can be used to drive an external decoder directly. Although the module baseband response extends down to DC, data formats containing a DC component are unsuitable and should not be used. This is because frequency errors and drifts between the transmitter and receiver occur in normal operation resulting in DC offset errors on the AF output. The time constant of the adaptive data slicer in the BiM2/3G is set at a reasonable compromise to allow the use of low code speeds where necessary whilst keeping settling times acceptably fast for battery-economised operation. RXD output on pin 12 is “true” sense, i.e. as originally fed to the transmitter. Antenna considerations and options The choice and positioning of transmitter and receiver antennas is of the utmost importance and is the single most significant factor in determining system range. The following notes are intended to assist the user in choosing the most effective arrangement for a given application. Nearby conducting objects such as a PCB or battery can cause detuning or screening of the antenna which severely reduces efficiency. Ideally the antenna should stick out from the top of the product and be entirely in the clear, however this is often not desirable for practical or ergonomic reasons and a compromise may need to be reached. If an internal antenna must be used, try to keep it away from other metal components and pay particular attention to the “hot” end (i.e. the far end), as this is generally the most susceptible to detuning. The space around the antenna is as important as the antenna itself. Microprocessors and microcontrollers tend to radiate significant amounts of radio frequency hash, which can cause desensitisation of the receiver if its antenna is in close proximity. 433MHz is generally less prone to this effect than lower frequencies, but problems can still arise. Things become worse as logic speeds increase, because fast logic edges are capable of generating harmonics across the UHF range which are then radiated effectively by the PCB tracking. In extreme cases system range can be reduced by a factor of 3 or more. To minimise any adverse effects, situate the antenna and module as far as possible from any such circuitry and keep PCB track lengths to the minimum possible. A ground plane can be highly effective in cutting radiated interference and its use is strongly recommended. A simple test for interference is to monitor the receiver RSSI output voltage, which should be the same regardless of whether the microcontroller or other logic circuitry is running or in reset. Radiometrix Ltd, BIM2/3G Data Sheet page 7 Three types of integral antenna are recommended: A) Helical Wire coil, connected directly to pin 2, open circuit at other end. This antenna is very efficient given it's small size (20mm x 4mm dia.). The helical is a high Q antenna, trim the wire length or expand the coil for optimum results. The helical de-tunes badly with proximity to other conductive objects. B) Loop A loop of PCB track tuned by a fixed or variable capacitor to ground at the 'hot' end and fed from pin 2 at a point 20% from the ground end. Loops have high immunity to proximity detuning. C) Whip This is a wire, rod, PCB track or combination connected directly to pin 2 of the module. Optimum total length is 15.5cm (1/4 wave @ 433MHz). Keep the open circuit (hot) end well away from metal components to prevent serious de-tuning. Whips are ground plane sensitive and will benefit from internal 1/4 wave earthed radial(s) if the product is small and plastic cased 0.5 mm enameled copper wire close wound on 3.2 mm diameter former RF 433 MHz = 24 turns A. Helical antenna Feed point 15% to 25% of total loop length RF-GND track width = 1mm 2 C2 C3 C4 C1 4 to 10 cm inside area RF B. Loop antenna 16.4cm C. Whip antenna wire, rod, PCB-track or a combination of these three RF 433 MHz = 16.4 cm total from RF pin. Fig.4: Antenna configuration (BiM2G @ 433.92MHz) Ultimate performance Easy of design set-up Size Immunity proximity effects Range open ground to similar antenna helical ** ** *** ** 200m loop * * ** *** 100m whip *** *** * * 300m (for BiM2G-433-15) Antenna selection chart Radiometrix Ltd, BIM2/3G Data Sheet page 8 Duty Cycle requirements The duty cycle is defined as the ratio, expressed as a percentage, of the maximum transmitter “on” time on one or more carrier frequencies, relative to a one hour period. Where an acknowledgement message is required, the additional transmitter “on” time shall be included. There is a 10% duty cycle restriction on 433.050-434.790 MHz band in most of the EU member states. The BIM2G is a RF module intended to be incorporated into a wide variety of applications and finished products, Radiometrix has no control over the end use of the BIM2G.The harmonised band 433.050 to 434.790 MHz as detailed in Annex 1 Band E of CEPT/ERC Recommendation 70-03 (which can be downloaded at http://www.ero.dk/scripts/docmanag98/dm.dll/QueryDoc?Cat=Recommendation) has list of countries where Duty Cycle restriction apply. Module users should, therefore, ensure that they comply with the stated Duty Cycle requirements of the version of CEPT/ERC Recommendation 70-03 in place at the time of incorporation of the BIM2G into their product. Please refer to Appendix A for duty cycle information on 868MHz band in which the BiM3G operates. Variants and ordering information The following variants are standard: Part number RF power (dBm) RSSI versions BIM2G-433-15-5V +10 BIM2G-433-64-5V +10 BIM2G-433-128-5V +10 Data rate (kbps) Frequency (MHz) 15 64 128 433.92 433.92 433.92 BIM2G-434-15-5V BIM2G-434-64-5V BIM2G-434-128-5V +10 +10 +10 15 64 128 434.42 434.42 434.42 BIM3G-869-15-5V BIM3G-869-64-5V BIM3G-869-128-5V +5 +5 +5 15 64 128 869.85MHz 869.85MHz 869.85MHz BIM3G-868-15-5V BIM3G-868-64-5V BIM3G-868-128-5V +10 +10 +10 15 64 128 868.3MHz 868.3MHz 868.3MHz CD versions BIM2G-433-15-CD-5V BIM2G-433-64-CD-5V BIM2G-433-128-CD-5V +10 +10 +10 15 64 128 433.92 433.92 433.92 BIM2G-434-15-CD-5V BIM2G-434-64-CD-5V BIM2G-434-128-CD-5V +10 +10 +10 15 64 128 434.42 434.42 434.42 BIM3G-869-15-CD-5V BIM3G-869-64-CD-5V BIM3G-869-128-CD-5V +5 +5 +5 15 64 128 869.85MHz 869.85MHz 869.85MHz BIM3G-868-15-CD-5V BIM3G-868-64-CD-5V BIM3G-868-128-CD-5V +10 +10 +10 15 64 128 868.3MHz 868.3MHz 868.3MHz For other frequency variants, please contact sales department. Evaluation platforms: 1. Universal Evaluation Kit 2. NBEK + BiM carrier Radiometrix Ltd, BIM2/3G Data Sheet page 9 Radiometrix Ltd, BIM2/3G Data Sheet 10 100 500 868.0 [mW] 600kHz 25mW <1% or LBT Duty Cycle 868.60 100kHz 868.70 10mW <1% 25kHz or WB No Spacing Channel Spacing Applications Alarm RF POWER [ERP] Non-specific SRD 500kHz <1% 25kHz 869.25 250kHz 500mW 869.65 869.70 50kHz 25mW <10% or LBT <10% 869.30 869.40 50kHz 50kHz 100kHz 869.20 No Spacing 25kHz 25kHz or Wide Band 300kHz 5mW 870.0 up to 100% Non-specific SRD Alarm Non-specific SRD 10mW 10mW 10mW <0.1% <0.1% or LBT 25mW 25kHz Social Alarm Alarm No Spacing Non-specific SRD CEPT/ERC Rec 70-03, 868 MHz Band Plan [MHz] Appendix A page 10 Radiometrix Ltd Hartcran House 231 Kenton Lane Harrow, Middlesex HA3 8RP ENGLAND Tel: +44 (0) 20 8909 9595 Fax: +44 (0) 20 8909 2233 [email protected] www.radiometrix.com Copyright notice This product data sheet is the original work and copyrighted property of Radiometrix Ltd. Reproduction in whole or in part must give clear acknowledgement to the copyright owner. Limitation of liability The information furnished by Radiometrix Ltd is believed to be accurate and reliable. Radiometrix Ltd reserves the right to make changes or improvements in the design, specification or manufacture of its subassembly products without notice. Radiometrix Ltd does not assume any liability arising from the application or use of any product or circuit described herein, nor for any infringements of patents or other rights of third parties which may result from the use of its products. This data sheet neither states nor implies warranty of any kind, including fitness for any particular application. These radio devices may be subject to radio interference and may not function as intended if interference is present. We do NOT recommend their use for life critical applications. The Intrastat commodity code for all our modules is: 8542 6000 R&TTE Directive After 7 April 2001 the manufacturer can only place finished product on the market under the provisions of the R&TTE Directive. Equipment within the scope of the R&TTE Directive may demonstrate compliance to the essential requirements specified in Article 3 of the Directive, as appropriate to the particular equipment. Further details are available on The Office of Communications (Ofcom) web site: http://www.ofcom.org.uk/radiocomms/ifi/ Information Requests Ofcom Riverside House 2a Southwark Bridge Road London SE1 9HA Tel: +44 (0)845 456 3000 or 020 7981 3040 Fax: +44 (0)20 7783 4033 [email protected] European Radiocommunications Office (ERO) Peblingehus Nansensgade 19 DK 1366 Copenhagen Tel. +45 33896300 Fax +45 33896330 [email protected] www.ero.dk