© Radiometrix Ltd

EMC compliant Data Transmitter and Receiver Modules ( TX2 & RX2)

Issue: 0150-1-2WW

TX2/RX2 data sheet

04 February 2001

CONTENTS

Typical features	Functional description
Transmitter - TX2	Receiver - RX2
TX2 transmitter	RX2 Receiver
TX2 Pin description	RX2 Pin description
Electrical Performance of TX2	Electrical Performance of RX2
Survival Maximums	Module test circuits
Module mounting considerations	Antenna requirements
Duty Cycle requirements	Variants & Ordering information

The TX2 and RX2 data link modules are a miniature PCB mounting UHF radio transmitter and receiver pair which enable the simple implementation of a data link at upto 160 kbit/s at distances upto 75 metres in-building and 300 metres open ground.

Left: TX2 transmitter Right: RX2 receiver

Features:

• CE certified by independent Notified Body
• Verified to comply with harmonised radio standard EN 300 220-3 by accredited Test Laboratory
• Verified to comply with harmonised EMC standard EN 301 489-3 by accredited Test Laboratory
• Data rates up to 160 kbps
• Usable range up to 300 m
• 433.92 MHz versions
• Fully screened
  
  

Available for operation at 433.92 MHz in Europe (including UK), both modules combine full screening with extensive internal filtering to ensure EMC compliance by minimising spurious radiations and susceptibilities. The TX2 and RX2 modules will suit one-to-one and multi-node wireless links in applications including car and building security, EPOS and inventory tracking, remote industrial process monitoring and computer networking. Because of their small size and low power requirements, both modules are ideal for use in portable, battery-powered applications such as hand-held terminals.

Transmitter - TX2

• 2 stage SAW controlled, FM modulated at upto 160kbps
• Operation from 2.2 to 6V
• +9dBm on 433.92MHz
• High efficiency, >15% , DC --> RF
• Improved frequency and deviation accuracy
• 2^nd harmonic, < -60dBc

Receiver - RX2

• Double conversion FM superhet
• SAW front end filter, image rejection 50dB
• Supply 3.0 to 6.0 Volts @ 13mA
• -96 dBm sensitivity @1ppm BER with 160kbps version
• -100 dBm sensitivity @ 1ppm BER with 40kbps-version
• -107 dBm sensitivity @ 1ppm BER with 14kbps-version
  
• Local Oscillator leakage, < -60 dBm

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Functional description:
TX2 Transmitter

The TX2 transmitter module is a two stage, SAW controlled FM transmitter operating between 2 and 6 V and is available in 433.92MHz and 418.00 MHz versions. The 433.92 MHz unit is type-approved to EN 300 220-3 for European use and will deliver +9 dBm from a 5V supply at 12mA, while the 418.00 MHz unit has MPT 1340 type-approval for U.K. use and deliveres -6dBm from a 5V supply at 5mA. Both modules measure 12 x 32 x 3.8 mm.

Figure1 : TX2 block diagram
Click on the image for EXPANDED VIEW

Pin description

RF GND (pin 1)
RF ground pin, internally connected to the module screen and pin 4 (0 Volt). This pin should be connected to the RF return path (e.g. coax braid, main PCB ground plane etc.)

RF out (pin 2)
50W RF output to the antenna, it is DC isolated internally. (see antenna section of TX2 applications note for suggested antenna/feeds).

Figure 2: TX2 physical dimensions
Click on the image for EXPANDED VIEW

Vcc (pin 3)
+ve supply pin. The module will generate RF when the Vcc supply is present. Max ripple content 0.1V_p-p. A 100nF de-coupling ceramic capacitor is suggested.

0 V (pin 4)0
Supply ground connection, connected to pin 1 and screen.

TXD (pin 5)
This DC coupled modulation input will accept either serial digital data ( 0 V to Vcc levels) or high level linear signals. Input impedance is 100 kW.

RX2 receiver

The RX2 module is a double conversion FM superhet receiver capable of handling date rates of upto 160kbit/s. The SIL style RX2 receiver measures 48 x 17.5 x 4.5 mm. It will operate from a supply of 3-6V and draws just 14mA when receiving. A fast-acting carrier detect and a power-up enable time of less than 1ms. This allows effective duty cycle power saving and a -107dBm sensitivity. This, combined with a SAW front-end filter results in an excellent RF performance and EMC conformance.

Figure 3: RX2 block diagram
Click on the image for EXPANDED VIEW

Figure 4: RX2 physical dimensions
Click on the image for EXPANDED VIEW

Pin description

RF in (pin1)
50W RF input from the antenna, it is DC isolate internally. (see antenna section of RX2 applications note for suggested antenna/feeds).

RF GND (pin2)
RF ground pin, internally connected to the module screen and pin 4 (0 Volt). This pin should be connected to the RF return path (e.g. coax braid, main PCB ground plane etc.)

CD (pin 3)
The Carrier Detect may be used to drive an external PNP transistor to obtain a logic level carrier detect signal, see test circuit / applications note. If not required it should be connected to pin 5 (Vcc).

0V (pin 4)
Supply ground connection, connected to pin 1 and screen.

Vcc (pin 5)
+ve supply pin. +3.0 to +6.0V @ <17mA . The supply must be clean <2mV_p-pripple. A 10µF de-coupling capacitor and 10W series resistor is recommended if a clean supply is not available.

AF (pin 6)
This is a buffered and filtered analogue output from the FM demodulator. It has a standing DC bias of 1.2V and 400mVp_-p base band signal. It is useful as a test point or to drive linear decoders. Load impedance should be > 2kW and <100pF.

RXD (pin 7)
This digital output from the internal data slicer is a squared version of the signal on pin 6 (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.

Survival Maximums

Operating temperature:	-10°C to +55°C
Storage temperature :	-40°C to + 100°C
TX2, all variants
Vcc (pin 3)	-0.1V to +10.0V
Data input (pin 5)	-0.1V to +10.0V
RF out (pin 2)	±50V @ < 10MHz , +20dBm @ > 10MHz
RX2, all variants
Vcc (pin 5)	-0.1V to +10.0V
Data , CD & AF (pin 7,3,6)	-0.1V to + Vcc V
RF input (pin 1)	±50V @ < 10MHz , +13dBm @ > 10MHz

note: Operation of the TX2 above 6V may cause the module to exceed the licensed power level.

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Electrical Performance: TX2 transmitter

	pin	min.	typ.	max.	units	notes
DC LEVELS
supply voltage	3	2.2	3.0	4.0	V	3V version
supply voltage	3	4.0	5.0	6.0	V	5V version
CURRENT & RF POWER
TX2-418-3V
supply current @ Vcc = 3V	3	4	6	10	mA
RF power @ Vcc = 3V	2	-7	-3	+3	dBm	1
TX2-418-5V
supply current @ Vcc = 5V	3	4	6	10	mA
RF power @ Vcc = 5V	2	-7	-3	+3	dBm	1
TX2-433-3V
supply current @ Vcc = 3V	3	4	6	10	mA
RF power @ Vcc = 3V	2	0	+4	+6	dBm	1
TX2-433-5V
supply current @ Vcc = 5V	3	7	10	14	mA
RF power @ Vcc = 5V	2	+6	+9	+12	dBm	1
RF
2nd harmonic	2	-	-65	-54	dBc	1
harmonics @ > 1GHz	2	-	-50	-40	dBc	1
initial frequency accuracy	-	-30	0	+30	kHz
overall frequency accuracy	-	-70	-	+70	kHz
FM deviation (+/-)	-	20	25	30	kHz
modulation bandwidth @ -3dB	-	DC	-	20	kHz
modulation bandwidth @ -3dB	-	DC	-	100	kHz	2
modulation distortion (THD)	-	-	5	10	%
power up time to full RF	-	-	-	100	µs

note:	1. Measured into a 50W load.
	2. 160kbps version

Electrical Performance: RX2 Receiver

Unless otherwise noted:

Figures apply to 5V versions unless noted otherwise

Vcc = 5.0V, temperature 20°C unless noted other wise.

	pin	min.	typ.	Max.	units	notes
DC LEVELS
supply voltage, Vcc standard	5	4.0	5.0	6.0	V
supply voltage, Vcc, 3V version	5	3.3	3.5	4.0	V
supply current	5	11	13	17	mA
supply ripple	5	-	-	2	mVP-P	1
data output high, 100µA source	7	-	Vcc-0.6	-	V
data output low, 100µA sink	7	-	0.4	-	V
load capacitance on AF / Data	6,7	-	-	100	pF
RF
RF sensitivity for 10dB (S+N)/N	1,6	-	-113	-107	dBm	14kbps version
RF sensitivity for 10dB (S+N)/N	1,6	-	-107	-100	dBm	40kbps version
RF sensitivity for 10dB (S+N)/N	1,6	-	-96	-	dBm	160kbps version
RF sensitivity for 1ppm BER	1,6	-	-107	-100	dBm	14kbps version
RF sensitivity for 1ppm BER	1,6	-	-100	-93	dBm	40kbps version
RF sensitivity for 1ppm BER	1,6	-	-90	-	dBm	160kbps version
CD threshold	1,3	-	-107	-97	dBm	14kbps version
CD threshold	1,3	-	-100	-90	dBm	40kbps version
CD threshold	1,3	-	-107	-	dBm	160kbps version
IF band width	-	-	250	-	kHz
initial frequency accuracy	1	-30	0	+30	kHz
E.M.C.
image rejection (2*fIF)	1	-	-50	-	dB	2
spurious responses upto 1GHz	1	-	-70	-	dB	2
Local Oscillator leakage, conducted	1	-	-65	-	dBm
Local Oscillator leakage, radiated	-	-	-70	-	dBm
AF BASE BAND
baseband bandwidth @ -3dB	6	0.006	-	7	kHz	14kbps version
baseband bandwidth @ -3dB	6	0.060	-	20	kHz	40kbps version
baseband bandwidth @ -3dB	6	0.250	-	91	kHz	160kbps version
AF level	6	-	-450	-	mVP-P
DC offset on AF	6	0.8	1.2	1.6	V
distortion on recovered AF	6	-	0.5	1	%
ultimate (S+N)/N	6	35	45	-	dB
ultimate (S+N)/N	6	-	28	-	dB	160kbps version
DYNAMIC TIMING
Power up with signal present
power up to valid CD, TPU-CD	-	-	1	-	ms
power up to stable data, TPU-DAT	-	-	20	-	ms	14kbps version
power up to stable data, TPU-DAT	-	-	5	-	ms	40kbps version
power up to stable data, TPU-DAT	-	-	3	-	ms	160kbps version
power up to stable AF, TPU-AF	-	-	600	-	µs	160kbps version
power up to valid data, TPU-DAT	-	-	700	-	µs	160kbps version
Signal applied with supply on
signal to valid CD, TSIG-CD	-	-	0.5	-	ms
signal to stable data, TSIG-DAT	-	-	15	-	ms	14kbps version
signal to stable data, TSIG-DAT	-	-	3	-	ms	40kbps version
signal to stable data, TSIG-DAT	-	-	750	-	µs	160kbps version
signal to stable data, TSIG-AF	-	-	100	-	µs	160kbps version
signal to valid CD, TSIG-CD	-	-	200	-	µs	160kbps version
time between data transitions	7	15	-	0.07	ms	4, 14kbps version
time between data transitions	7	1.5	-	0.025	ms	4, 40kbps version
time between data transitions	7	6.25	-	500	µs	4, 160kbps version
mark:space ratio	-	20	50	80	%	3

notes:	1. For 6dB (S+N)/N degradation on wanted -100dBm signal
	2. Receiver spurious responses are at FRF +/- (n x 15.92MHz), n=1,2,3 etc.
	3. Average over 30ms (14kbps), 3ms (40kbps), 1ms (160kbps) at maximum bit rate.
	4. Values for 50:50 mark to space (i.e. square wave)

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Module test circuits

Figure 5: TX2 test circuit
Click on the image for EXPANDED VIEW

Figure 6: RX2 test circuit
Click on the image for EXPANDED VIEW

*	The PNP transistor (eg: BC558Benables a CMOS compatible Carrier Detect signal to be derived from pin 3. If no CD signal required pin 3 should be connected directly to pin 5 (Vcc).

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Module mounting considerations

The modules may be mounted horizontally or vertically on an area of ground plane preferably close to the antenna to minimise feed length. The receiver and it's antenna should be kept away from sources of interference (micro's, SMPS etc.). The modules may be potted if required in a viscous compound which can not enter the screen can.

Warning: Do NOT wash the modules. They are not hermetically sealed.

Figure 7: module mounting options
Click on the image for EXPANDED VIEW

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Antenna requirements

Three types of integral antenna are recommended and approved for use with the module:

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 de-tuning.
C) Whip	This is a wire, rod ,PCB track or combination connected directly to pin 2 of the module. Optimum total length is 17cm (1/4 wave @ 418MHz) 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

	A	B	C
	helical	loop	whip
Ultimate performance	**	*	***
Easy of design set-up	**	*	***
Size	***	**	*
Immunity proximity effects	**	***	*
Range open ground to similar antenna (for TX2-433-40 & RX2-433-14)	200m	100m	300m

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.

Figure 8: antenna configurations
Click on the image for EXPANDED VIEW

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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 TX2-433 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 TX2-433.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 TX2-433 into their product. It should be noted that the stated Duty Cycle must not be exceeded otherwise any approval granted for the TX2-433 will be invalidated.

Type Approval

TX2/RX2 is CE Certified by independent Notified Body according to the R&TTE Directive (1999/5/EC). They are verified to comply with Radio standard ETSI EN 300 220-3 and EMC standard ETSI EN 301 489-3 by UKAS accredited Test Laboratory.

Variants and Ordering information

The TX2 transmitter and RX2 receiver are manufactured in several variants

Supply voltage:	5V ( 4V to 6V TX2 & RX2)
	3V ( 3V to 4V for RX2, 2.2V to 4V for TX2)
RX data rate:	Slower version, 7kHz baseband BW, data rate up to 14kbps
	Faster version, 20kHz baseband BW, data rate up to 40kbps
	Very fast version 91kHz baseband BW, data rate up to 160kbps
TX data rate	Faster version, 20kHz baseband BW, data rate up to 40kbps
	Very fast version, 100kHz baseband BW, data rate up to 160kbps

The following are standard:

TX2-433-40-5V:	433.92 MHz , 5V TX , 10mW
TX2-433-160-5V:	433.92 MHz , 5V TX , 10mW
RX2-433-14-5V:	433.92 MHz , 5V RX , 14kbps
RX2-433-40-5V:	433.92 MHz , 5V RX , 40kbps
RX2-433-160-5V:	433.92 MHz , 5V RX , 160kbps

3V versions of the above are available and should be ordered with a -3V suffix on the part number. (e.g. RX2-433-14-3V is set-up for 3V to 4V operation)

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 Radiocommunications Agency (RA) web site:
http://www.radio.gov.uk/topics/conformity/conform-index.htm

***End of TX2/RX2 data sheet***