FM TRANSMITTER MODULES. FMTX1- XXXX FM TRANSMITTER MODULES. FMTX1- XXXX FEATURES COMPLETE TRANSMITTER SIL MODULE. WIDE 10Kbps BANDWIDTH. WIDE VOLTAGE A RANGE 6 - 12V DC. LOW VOLTAGE F RANGE 2.5 - 4V DC. 5 VOLT F5 RANGE AVAILABLE. DTI APPROVED FOR USE IN THE U.K. DIRECTLY COMPATIBLE WITH R.F. SOLUTIONS FM RECEIVER UNITS. UP TO 200 METRES RANGE. AVAILABLE AS 418MHz (0.25mW ERP) AVAILABLE AS 433MHz (10mW ERP) ANALOGUE OR DIGITAL INPUTS. APPLICATIONS ALARM SYSTEMS REMOTE SWITCHING REMOTE TELEMETRY SYSTEMS. REMOTE DATA COMMS PAGERS GARAGE DOOR OPENERS GENERAL DESCRIPTION The R.F. Solutions range of FM Radiometrix Transmitters are complete single in line board modules capable of transmitting analogue or digital data up to 200 metres. The units are suitable for general purpose telemetry applications where small size and high data rates are needed. These transmitters are designed to be used in conjunction with R.F. Solutions series of Receivers (see data sheet FMRX1-XXX). Each unit is supplied complete and ready to operate. Several versions of the transmitter are available in either 418 or 433MHz frequency, with either 0.25mW or 10mW ERP (RF power output) The transmitter may also be supplied as a bare board or as a custom solution unique to customer-specific requirements. Please contact R.F. Solutions for further information. BLOCK DIAGRAM Vcc Vcc 3 3 LOW PASS LOW PASS FILTER FILTER 47K WBFM SAW 418MHz 47K WBFM SAW 418MHz DATA 5 DATA 5 MODULATOR OSCILLATOR BAND PASS MODULATOR OSCILLATOR BAND PASS IN IN R.F. R.F. FILTER FILTER OUT OUT 470pF 2 470pF 2 0V 0V 0V 0V 4 1 4 1 DDSS000000002200 RReevv 22..11 JJuullyy 9999 11999999 RREEGG NNoo 227777 44000011,, EENNGGLLAANNDD.. Page 1 Page 1FM TRANSMITTER MODULES. FMTX1- XXXX FM TRANSMITTER MODULES. FMTX1- XXXX OPERATIONAL DESCRIPTION Data in can accept data in either digital or direct analogue form (AFSK). The input frequency bandwidth ranges from DC to 10KHz however, it is not possible to pass data with a DC component because of frequency errors and drifts between the transmitter and receiver. The frequency differences between transmitter and receiver will produce a DC offset error which will result in the receiver module producing errors on long high or low pulses which exceed the maximum pulse width specification (please refer to the Receiver data sheet, RF Solutions Doc FMRX1-XXX). Data in should be driven from a CMOS logic output. The power supply for the CMOS circuit should be the same as that for the transmitter. Analogue drive (e.g. two tone FSK) is possible however the peak to peak level must be in the range 5 to 9V, and never fall below 0V. Please note that there may be some 2nd harmonic distortion due to the varactor modulator (typically <15%). This can be reduced somewhat by predistorting the analogue waveform. LICENCE EXEMPTION This range of Radio transmitters is approved by the Department of Trade & Industry (D.T.I. Specification MPT1340) in the U.K., and therefore the user requires no radio operating licence in the U.K. Please note however the following requirements to comply with MPT1340 1. All transmitters shall use integral antennas only. Receivers may use an external or integral antenna. An integral antenna is defined as one which is designed to be connected permanently to the transmitter or receiver without the use of an external feeder. 2. The equipment in which the module is used must carry an inspection mark located on the outside of the equipment which is clearly visible. It shall state MPT1340 W.T. Exempt. The minimum dimensions of the mark shall be 10 x 15mm and the figure height shall be not less than 2mm. ANTENNA DESIGN The range achieved from the system is dependant on the choice and position of the antenna. The space around the antenna is as important as the antenna itself. The optimum position is to locate the antenna so that is protrudes directly out the top of the transmitter box. If this is not possible due to other design constraints, try to keep the antenna away from other metal in the system such as transformers, batteries and PCB tracks, especially ground planes. In particular, the HOT end of the antenna should be kept as far away as possible from these. For further information on Antenna design please see our full product catalogue which gives recommended applications guidance. PIN ASSIGNMENTS PIN No NAME DESCRIPTION 1 R.F. GND Ground Plane. The Antenna radiates against this (Internally connected to pin 4) 2 R.F. OUT Connect to Antenna (Output Impedance = 50) 3 Vcc Supply Voltage 4 Vss 0 Volt Supply (Internally connected to pin 1) 5 DATA IN Input pin. Should be driven by CMOS Drive with same supply as pin 3 DDSS000000002200 RReevv 22..11 JJuullyy 9999 11999999 RREEGG NNoo 227777 44000011,, EENNGGLLAANNDD.. Page 2 Page 2