LMT2 RADIOMETRIX | Alldatasheet

Document overview

  • Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
  • PDF pages: 11

Technical content

Features

  • Conforms to EN 300 220-3 and EN 301 489-3
  • High performance double superhet. PLL synthesizer with TCXO
  • quasi-dc (peak sampling) data recovery circuit (for enhanced performance on unbalanced datastreams)
  • SAW front-end filter
  • Data rates up to 5 kbps for standard module
  • Usable range over 1km
  • Fully screened. Low profile
  • Feature-rich interface (RSSI, analogue and digital baseband)
  • Re-programmable via RS232 interface
  • Low power requirements

Applications

  • Handheld terminals
  • EPOS equipment, barcode scanners
  • Data loggers
  • Industrial telemetry and telecommand
  • In-building environmental monitoring and control
  • High-end security and fire alarms
  • DGPS systems
  • Vehicle data up/download
  • Heavy vehicle/machinery controls Technical Summary
  • Operating frequency: 433.875-434.650MHz (EU band) 458.525 - 459.1MHz (UK band)
  • Other custom UHF bands
  • 32 channels
  • Transmit power: +10dBm (10mW) / +20dBm (100mW)
  • Supply range: 3.1 – 15V (TX @ 10mW and RX), 4.1 – 15V (TX @ 100mW)
  • Current consumption: 34mA @ 10mW, 90mA @ 100mW (transmit) and 20mA (receive)
  • Data bit rate: 5kbps max. (standard module)
  • Receiver sensitivity: -118dBm (for 12 dB SINAD)
  • Serial configuration by inverted RS232 at 3V CMOS level UHF Narrow Band FM Low Cost multi channel radio modulesUHF Narrow Band FM Low Cost multi channel radio modulesUHF Narrow Band FM Low Cost multi channel radio modulesUHF Narrow Band FM Low Cost multi channel radio modules The LMT2 transmitter and LMR 2 receiver modules offer a multi channel, low power, and reliable data link. This makes the LMT2/LMR2 pair ideally suited to those low power applications where existing wideband modules have insufficient range, or where low cost multi-channel operation is neede d without compromising on R F specification or regulatory requirement. Radiometrix Hartcran House, 231 Kenton Lane, Harrow, HA3 8RP, England Issue 2, 01 November 2007 LMT2/LMR2 NEW Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233 Figure 1: LMT2 transmitter and LMR2 receiver

Radiometrix Ltd LMT2/LMR2 Data Sheet page 2 Figure 2: LMT2 block diagram

Radiometrix Ltd LMT2/LMR2 Data Sheet page 3 Pin description – LMT2 Pin Name Function 1a Vcc 3.1 – 15V power supply (@ 10mW) 4.1 – 15V power supply (@ 100mW) 2a 0V Ground 3a TXE Transmit Enable (active low) 4a TXD DC coupled input for 3V CMOS logic. Rin=47kΩ 5a No pin Not present in LMT2 1b P0/PGM Parallel Channel select LSB Serial frequency programming / configuration1 2b P1 Parallel Channel select 3b P2 Parallel Channel select 4b P3 Parallel Channel select MSB 5b No pin Not present in LMT2 Notes: 1. Serial programming is by an inverted, CMOS logic level, 2400 baud RS232 datastream applied to the P0 pin. 2. Channel select inputs have pullups (50k Ω ) to 3v internal rail. Do not exceed 3V logic levels on this port. 3. Channel select inputs are active low 4. TXE has a 100k Ω pullup to Vcc 5. All pins are on an 0.1" grid 6. The pins 5a/b are not present, but are included in footprint for compatibility with other units in this family 7. In the 'off' state a PIN switch open circuits the RF output pin. There are no 'off' state spuri. 8. 10mW unit will operate (with marginally reduced specifications and lower (6-8mW) output power) from a 3.0V rail. This must be well regulated and without noise or ripple, as in this state the unit's internal regulator no longer operates, and provides no supply rejection. 9. 100mW versions should not be run continuously from supply voltages > 9v Figure 3: LMT2 footpint (top view)

Radiometrix Ltd LMT2/LMR2 Data Sheet page 4 Figure 4: LMR2 block diagram

Radiometrix Ltd LMT2/LMR2 Data Sheet page 5 Pin description – LMR2 Pin Name Function 1a Vcc 3.1 – 15V power supply 2a 0V Ground 3a RXE Receiver Enable (active high) 4a RXD Data out (open collector, no pullup) 5a AF out 700mV p-p audio. DC coupled, approx 0.8v bias.\` 1b P0/PGM Parallel Channel select LSB Serial frequency programming / configuration1 2b P1 Parallel Channel select 3b P2 Parallel Channel select 4b P3 Parallel Channel select MSB 5b RSSI DC level between 0.5v and 2.2v. 60dB dynamic range NOTES: 1. Serial programming is by an inverted, cmos logic level, 2400 baud RS232 datastream applied to the P0 pin. 2. Channel select inputs have pullups (50k Ω ) to 3v internal rail. Do not exceed 3v logic levels on this port. 3. Channel select inputs are active low 4. All pins are on an 0.1" grid 5. Data recovery circuit used for RXD is not a simple 'average and compare' type. It is a peak sampling quasi-DC coupled design, allowing a greater than usual flexibility in data format. 6. Unit will operate (with marginally reduced specifications) from a 3.0v rail. This must be well regulated and without noise or ripple, as in this state the unit's internal regulator no longer operates, and provides no supply rejection. Figure 5: LMR2 footpint (top view)

Radiometrix Ltd LMT2/LMR2 Data Sheet page 6 Serial interface commands 2400 baud RS232. 8 bit data, no parity, 1 start bit, 1 or 2 stop bits. Serial data is sent to the unit on one of the parallel channel select pins (P0). It is very important that the unit does not 'decode' switch bounce in ordinary operation as a command string, or spurious re- writing of the e2prom will result. For this reason the user must send the 16 character string ENABLESERIALMODE (followed by a carriage return) to activate the serial command mode before sending any of the command strings listed below. Command mode is disabled on power down, or on reception of a # character. To successfully program the unit, it must be enabled ('RXE high (rx) or TXE low (tx)). GOCHAN aa Serially select channel aa, where aa is ch0 to ch31 LOAD aa nnnnn Set value of N register for channel aa, where aa is Channels 0 to 31 SETPAR Channel selected by 4 bit parallel inputs (ch0 to ch15 only) SETSER Channel selected by most recent GOCHAN operation RVALUE rrrr Set value for R register SINGLE nnnnn Set value of N for single channel operation. N value NOT stored in EEPROM <cr> Process entry / Clear all buffers # Disable command mode aa = a two digit channel number from 00 to 31 nnnnn = synthesizer N register value (up to 65535) rrrr = synthesizer R register value (up to 16383) 1735625 900.433 === kHz MHz f fN cingChannelspa RF TX kHz MHz f fR cingchannelspa TCXO 13== , So R=520 1650025 MHz f MHzfN cingChannelspa RF RX Note: A pause of at least 50ms must be allowed between command strings (EEPROM programming time). SINGLE mode does not store the N value in EEPROM. Therefore the unit is inoperative after a power down until either another valid SINGLE command is received, or mode is changed by a GOCHAN, SETPAR or SETSER command. SINGLE mode is intended for frequency agile applications.

Radiometrix Ltd LMT2/LMR2 Data Sheet page 7 LMT2, LMR2 channels are spaced at 50kHz interval into two frequency groups. 50kHz spacing between sequential channels minimises adjacent channel interference. e.g. 433MHz band Serial or Parallel channel select Frequency (MHz) Serial channel select Frequency (MHz) 16 433.875 0 (P3:P0 = HHHH)* 433.900 17 433.925 1 433.950 18 433.975 2 434.000 19 434.025 3 434.050 20 434.075 4 434.100 21 434.125 5 434.150 22 434.175 6 434.200 23 434.225 7 434.250 24 434.275 8 434.300 25 434.325 9 434.350 26 434.375 10 434.400 27 434.425 11 434.450 28 434.475 12 434.500 29 434.525 13 434.550 30 434.575 14 434.600 31 434.625 15 (P3:P0=LLLL)* 434.650 Note: Parallel select pins: H=3V, L= 0V

Radiometrix Ltd LMT2/LMR2 Data Sheet page 8 Condensed specifications Frequency 433MHz EU band, and 458MHz UK band As supplied: EU version: 433.875 - 434.65MHz (25kHz steps) UK version 458.525 - 459.1MHz (25kHz steps) Other custom UHF bands Frequency stability ±1.5kHz Channel spacing 25kHz Number of channels 16 channels controlled by parallel port or 32 via RS232 interface Operating temperature -10 ºC to +60 ºC (Storage -30 ºC to +70 ºC) Spurious radiations Compliant with ETSI EN 300 220-3 and EN 301 489-3 Transmitter Output power +10dBm (10mW) ±1dB (factory adjustable 1 - 25mW) +20dBm (100mW) ±1dB (factory adjustable 25 - 100mW) Peak deviation ±3kHz TX on switching time 30ms from TXE transition Modulation type FSK (F3D) TX modulation bandwidth DC – 5kHz (3V CMOS compatible) Adjacent channel TX power <-37dBm TX spurious <-45dBm (no RF output in Standby) Supply Voltage 3.1V – 15V (1-25mW) 4.1 – 15V (25 – 100mW) Current 34mA @ 10mW (nominal) 65mA @ 50mW (nominal) 90mA @ 100mW (nominal) <5µA standby (TXE high or floating) Inputs data (CMOS/TTL compatible) Size 33 x 23 x 9mm Interface User 10 (8) pin 0.1" pitch dual row (5+5) header RF 2pin 0.1” pitch Recommended PCB hole size 1.2mm Receiver Sensitivity -118dBm for 12dB SINAD S/N ratio 35dB (min), 40dB (typ) on AF output AF bandwidth (-3dB) 4kHz image <-60db Othr spurious <-70dbm Blocking Better than 84dB Adjacent channel <-60dB LO re-radiation -70dBm Supply Voltage 3.1V – 15V Current 20mA receive <1µA standby (RXE low) Outputs RSSI, audio, data (quasi DC data recovery circuit) Size 46 x 23 x 9 mm Interface User 10 pin 0.1" pitch dual row (5+5) header RF 2pin 0.1” pitch Recommended PCB hole size 1.2mm

Radiometrix Ltd LMT2/LMR2 Data Sheet page 9 RX Received Signal Strength Indicator (RSSI) The LMR2 has wide range RSSI that measures the strength of an incoming signal over a range of 60dB or more. This allows assessment of link quality and available margin and is useful when performing range tests. The output on pin 5b of the module has a standing DC bias of up to 0.5V with no signal, rising to 2.5V at maximum indication (RF input levels of -40dBm and above). ∆Vmin-max is typically 2V and is largely independent of standing bias variations. Output impedance is 40k Ω . Pin 5b can drive a 100µA meter directly, for simple monitoring. 0.2 0.4 0.6 0.8 1.2 1.4 1.6 1.8 2.2 2.4 2.6 -140 -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 RF level (dBm) RSSI output (V) Figure 6: typical RSSI level with respect to received RF level at LMR2 antenna pin Antenna requirements Three types of integral antenna are recommended and approved for use with the module: A) Whip This is a wire, rod ,PCB track or combination connected directly to RF pin of the module. Optimum total length is 16.4cm (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 B) Helical Wire coil, connected directly to RF pin, 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. C) Loop A loop of PCB track tuned by a fixed or variable capacitor to ground at the 'hot' end and fed from RF pin at a point 20% from the ground end. Loops have high immunity to proximity de-tuning. A B C whip helical loop Easy of design set-up * * Immunity proximity effects * * Range open ground to similar antenna 500m 200 100

Radiometrix Ltd LMT2/LMR2 Data Sheet page 10 The antenna choice and position directly controls the system range. Keep it clear of other metal in the system, particularly the 'hot' end. The best position by far, is sticking out the top of the product. This is often not desirable for practical/ergonomic reasons thus a compromise may need to be reached. If an internal antenna must be used, try to keep it away from other metal components, particularly large ones like transformers, batteries and PCB tracks/earth plane. The space around the antenna is as important as the antenna itself. A. Helical antenna B. Loop antenna RF C1C2 C4C3 RF-GND C. Whip antenna 16.4cm RF 0.5 mm enameled copper wire close wound on 3.2 mm diameter former

433 MHz = 24 turns

Feed point 15% to 25% of total loop length track width = 1mm 4 to 10 cm inside area wire, rod, PCB-track or a combination of these three 433 MHz = 16.4 cm total from RF pin. RF Ordering Information:Ordering Information:Ordering Information:Ordering Information: Part No.Part No.Part No.Part No. DescriptDescriptDescriptDescriptionionionion Frequency band Frequency band Frequency band Frequency band (MHz)(MHz)(MHz)(MHz) RF powerRF powerRF powerRF power (mW)(mW)(mW)(mW) Channel spacingChannel spacingChannel spacingChannel spacing (kHz)(kHz)(kHz)(kHz) Data rateData rateData rateData rate kbpskbpskbpskbps LMT2-433-5 Transmitter 433.875-434.650 10 25 5 LMR2-433-5 Receiver 433.875-434.650 25 5 LMT2-458-5 Transmitter 458.525 - 459.1 100 25 5 LMR2-458-5 Receiver 458.525 - 459.1 25 5 LMT2-433-5-12k5 Transmitter 433.875-434.650 10 12.5 5 LMR2-433-5-12k5 Receiver 433.875-434.650 12.5 5 LMT2-458-5-12k5 Transmitter 458.525 - 459.1 100 12.5 5 LMR2-458-5-12k5 Receiver 458.525 - 459.1 12.5 5 LMT2-433-10 Transmitter 433.875-434.650 10 25 10 LMR2-433-10 Receiver 433.875-434.650 25 10 LMT2-458-10 Transmitter 458.525 - 459.1 100 25 10 LMR2-458-10 Receiver 458.525 - 459.1 25 10 Note: Also available on the other UHF band frequencies subject to SAW filter availability. e.g. 315, 419, 429, 448, 465MHz etc. Figure 7: Antenna types

231 Kenton Lane

Harrow, Middlesex HA3 8RP ENGLAND Tel: +44 (0) 20 8909 9595 Fax: +44 (0) 20 8909 2233 sales@radiometrix.com 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 information.requests@ofcom.org.uk European Radiocommunications Office (ERO) Peblingehus Nansensgade 19 DK 1366 Copenhagen Tel. +45 33896300 Fax +45 33896330 ero@ero.dk www.ero.dk