Data Sheet(pdf)

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
TX2A/RX2G
Issue 3, 13 November 2012
UHF FM Data Transmitter and Receiver Modules
The TX2A and RX2G data radio modules
are PLL synthesiser based miniature
PCB mounting UHF radio transmitter
and receiver pair which enable the
simple implementation of a wireless
data link at up to 64 kbps at distances
up to 75 metres in-building and 300
metres open ground.
Features
 Designed for compliance with EN 300
Figure 1: RX2G-433-15 & TX2A-433-64
220-3 (radio) and EN 301 489-3 (EMC) standards
 Data rates up to 128kbps
 Usable range up to 300m
 Versions available on 433.92MHz, 434.42MHz and 434.525MHz
 Fully screened
Available for operation at 433.92MHz or 434.42MHz in the UK and Europe, both modules combine full
screening with extensive internal filtering to ensure EMC compliance by minimising spurious radiations and
susceptibilities. The TX2A and RX2G 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.
Technical Summary
Transmitter - TX2A
 Crystal-locked PLL, FM modulated at up to 64 Kbps
 Operation from 2.2V to 16V (Dependent on version)
 +10dBm on 433.92MHz
 High efficiency, >30%, DC to RF
 Improved frequency and deviation accuracy
 2nd harmonic, > -60dBc
Receiver - RX2G
 Single conversion FM superhet
 SAW front end filter gives >50dB image rejection
 Supply: +5V (± 10%) or 5.1 – 16V (regulator version)
 Current consumption: 10mA (typ.)
 -102dBm sensitivity @ 1ppm BER, 64kbps version
 -108dBm sensitivity @ 1ppm BER, 15kbps version
 RSSI output with 50dB range
 Extremely low LO leakage, -125dBm typical
Evaluation platforms: Universal Evaluation Kit, NBEK + SIL carrier
Radiometrix Ltd, TX2A/RX2G Data Sheet
page 1
Functional description
The TX2A transmitter module is a crystal based PLL controlled FM transmitter operating between 2.2V and 16V
and is available in 433.92MHz. The TX2A module is type approved to EN 300 220-3 for European use and
delivers nominally +10dBm at 11mA. The module measures 32 x 12 x 3.8 mm.
The RX2G module is a single conversion FM superhet receiver capable of handling data rates of up to 64kbps.
RX2G needs a regulated 5V supply and draws 10mA when receiving. The RX2G features a fast power-up time
for effective duty cycle power saving and a signal strength (RSSI) output with 50dB of range. Full screening and
a SAW front-end filter give good immunity to interference. The SIL style RX2G measures 48 x 17.5 x 4.5 mm
excluding the pins.
TX2A transmitter
supply
regulator
2
RF out
433.92 MHz
band pass
filter
buffer
VCO
3
RF gnd
32
5
2.2 -- 16V
4
En

ref
osc
35kHz
LPF
7
TXD
Loop
Filter
6
0V
1
Fig. 2: TX2A block diagram
Pin description:
RF GND
(pins 1&3)
RF ground, internally connected to the module
screen and pin 6 (0V). These pins should be
directly connected to the RF return path - e.g.
coax braid, main PCB ground plane etc.
RF OUT
(pin 2)
50 RF output to the antenna. Internally DCisolated. See antenna section of apps notes for
details of suitable antennas.
En
(pin 4)
Tx enable. <0.15V shuts down module (current
<1A). >1.7V enables the transmitter.
Impedance ~1M. Observe slew rate
requirements (see apps notes).
3.8 mm
32 mm
12.0
mm
12.5
mm
TX2A
Radiometrix
PCB level
15.24 mm
1
2
4
3
5
6
7
1 = RF GND
2 = RF OUT
3 = RF GND
4 = En
5 = Vcc
6 = 0V
7 = TXD
7 holes, 0.7 mm dia, pin spacing 2.54 mm
Fig 3: TX2A physical dimensions
Vcc
(pin 5)
+2.2V to +16V DC supply. Max ripple content 0.1VP-P. Decoupling is not generally required.
0V
(pin 6)
DC supply ground. Internally connected to pins 1 & 3 and module screen.
TXD
(pin 7)
DC-coupled modulation input. Accepts serial digital data at 0V to 2.5V levels.
See applications notes for suggested drive methods. Input is high impedance (>100k).
Notes: 1. The 3V and 5V supply variant TX2As intended for direct replacement to our SAW based TX2
modules and do not have internal regulator. They also have identical pin out as of TX2, hence lack pin
3 (GND) and pin 4 (Enable).
2. The TXD input of 3V and 5V versions require serial digital data at 0-Vcc levels. i.e. 0-3V and 0-5V
respectively
Radiometrix Ltd, TX2A/RX2G Data Sheet
page 2
RX2G receiver
Pin description
RF IN
(pin 1)
50 input from the antenna, DC isolated.
RF GND
(pin 2)
RF ground pins, internally connected to
the module screen and pin 6 (0V). This
pin should be connected to the RF return
path (coax braid, main PCB ground plane
etc.)
RF GND
(pin 3)
Not fitted on non-regulator 5V variant
Fig 4: physical dimensions & pin outs
En (Regulator version) (pin 4)
Rx enable. <0.15V shuts down module (current <1uA). >1.7V enables the receiver. Impedance ~1Mohm.
Observe slew rate requirements (see apps notes).
Not fitted on non-regulator 5V variant.
RSSI
(pin 5)
Received signal strength indicator with 60dB range. See page 4 for typical characteristics.
GND
(pin 6)
DC supply ground. Internally connected to pin 2 & 3 and module screen.
Vcc
(pin 7)
5V regulated DC supply. Max ripple content 0.1Vp-p.
Vcc (for regulator version)
(pin 7)
+4.5V to +16.0V DC supply. Max ripple content 0.1Vp-p. Decoupling is not generally required.
AF out (pin 8)
Buffered and filtered analogue output from the FM demodulator. Standing DC bias 2V approx. External load
should be >10k // <100pF.
RXD
(pin 9)
This digital output from the internal data slicer is a squared version of the signal on pin 8 (AF). It may be used
to drive external decoders. The data is true data, i.e. as fed to the transmitter.
Radiometrix Ltd, TX2A/RX2G Data Sheet
page 3
Absolute maximum ratings
Survival Maximums:
Exceeding the values given below may cause permanent damage to the module.
Operating temperature
Storage temperature
-20C to +70C
-40C to +100C
TX2A, all variants
Vcc (pin 3)
Data input (pin 5)
RF out (pin 2)
-0.3V to +16.0V
+/- 7V
50V DC 10dBm RF
RX2G all variants
Vcc (pin 7)
RSSI, AF, RXD (pins 5,8,9)
RF IN (pin 1)
-0.1V to +5.5V
-0.1V to +3V
±50V DC, +10dBm RF
Performance Specifications: TX2A
(Temperature = 20C unless stated)
pin
min.
typ.
max.
units
notes
DC LEVELS
supply voltage
supply voltage
supply voltage
3
3
3
2.2
4.0
3
3.0
5.0
-
4.0
6.0
16
V
V
V
-3V version
-5V version
STD
CURRENT & RF POWER
TX2A-433-64-3V
supply current @ Vcc = 3V
RF power
@ Vcc = 3V
3
2
9
+8
11
+10
13
+12
mA
dBm
1
TX2A-433-64-5V
supply current @ Vcc = 5V
RF power
@ Vcc = 5V
3
2
9
+8
11
+10
13
+12
mA
dBm
1
TX2A-433-64-STD
supply current @ Vcc = 5V
RF power
@ Vcc = 5V
3
2
9
+8
11
+10
13
+12
mA
dBm
1
RF
2nd harmonic
harmonics @ > 1GHz
initial frequency accuracy
overall frequency accuracy
2
2
-
-20
-25
-70
-60
+/-10
+/-10
-54
-40
+20
+25
dBc
dBc
kHz
kHz
FM deviation (+/-)
Modulation bandwidth @ -3dB
-
20
DC
27
-
35
35
kHz
kHz
modulation distortion (THD)
power up time to full RF
-
-
5
1
10
1.5
%
ms
1
1
Note: 1. Measured into a 50 load.
Radiometrix Ltd, TX2A/RX2G Data Sheet
page 4
Performance specifications: RX2G
(Vcc = 5.0V / temperature = 20 °C unless stated)
pin
min.
typ.
max.
units
notes
5
5
5
4.5
4.5
9
5.0
5.0
15
5.5
16
18
V
V
mA
1
RF sensitivity for 10dB (S+N/N)
RF sensitivity for 1ppm BER
RF sensitivity for 1ppm BER
RSSI range
IF bandwidth
Image rejection
IF rejection (10.7MHz)
LO leakage, conducted
1,2
1,2
1,2
1,2
1
1
1
50
100
-
-113
-108
-102
50
180
54
-125
-110
dBm
dBm
dBm
dB
kHz
dB
dB
dBm
Baseband
Baseband bandwidth @ -3dB
Baseband bandwidth @ -3dB
AF level
DC offset on AF out
Distortion on recovered AF
Load capacitance, AFout/RXD
8
8
8
8
8
3,8
0
0
200
1.5
-
250
2
1
-
7.8
50
350
2.5
5
100
kHz
kHz
mVP-P
V
%
pF
3,5
3,9
3,9
3,9
3,9
3,9
-
0.5
2
10
2
10
3
1
10
ms
ms
ms
ms
ms
ms
3, 15kbps
3, 15kbps, DS
3, 64kbps
3, 64kbps, DS
3, 128kbps
1,5
1,9
1,9
1,9
1,9
1,9
-
100
0.5
5
0.2
1.5
0.75
1
µs
ms
ms
ms
ms
ms
3, 15kbps
3, 15kbps, DS
3, 64kbps
3, 64kbps, DS
128kbps
Time between data transitions
9
Time between data transitions
9
Mark:space ratio
9
0.0667
0.0667
0.0156
0.0156
20
ms
ms
ms
ms
%
4, 15kbps
4, 15kbps DS
4, 64kbps
4, 64kbps DS
5
DC supply
Supply voltage
Supply voltage (regulator ver.)
Supply current
RF/ IF
15kbps
64kbps
15kbps version
64kbps version
2
3
3
DYNAMIC TIMING
Power up with signal present
Power up to valid RSSI
Power up to stable data
Power up to stable data
Power up to stable data
Signal applied with supply on
RSSI response time (rise/fall)
Signal to stable data
Signal to stable data
Signal to stable data
Notes:
-
-
50
10
0.5
1.5
75
0.2
3
80
1. Current increases at higher RF input levels (>-20dBm and above).
2. For received signal with ±30kHz FM deviation.
3. Typical figures are for signal at centre frequency, max. figures are for ±50kHz offset.
4. For 50:50 mark to space ratio (i.e. squarewave).
5. Average over 10ms (15kbps version) or 3ms (64kbps version) at maximum data rate
Radiometrix Ltd, TX2A/RX2G Data Sheet
page 5
Power supply requirement
The standard TX2A module incorporates a built-in regulator which delivers a constant 2.8V to the module
circuitry when the external supply voltage is 2.85V or greater, with 40dB or more of supply ripple rejection. This
ensures constant performance up to the maximum permitted supply rail and removes the need for external
supply decoupling except in cases where the supply rail is extremely poor (ripple/noise content >0.1Vp-p).
Note, however, that for supply voltages lower than 2.85V the regulator is effectively inoperative and supply
ripple rejection is considerably reduced. Under these conditions the ripple/noise on the supply rail should be
below 10mVp-p to avoid problems. If the quality of the supply is in doubt, it is recommended that a 10F lowESR tantalum or similar capacitor be added between the module supply pin (Vcc) and ground, together with a
10 series feed resistor between the Vcc pin and the supply rail.
The Enable pin allows the module to be turned on or off under logic control with a constant DC supply to the
Vcc pin. The module current in power-down mode is less than 1A.
NOTE: If this facility is used, the logic control signal must have a slew rate of 40mV/ms or more. Slew rates less
than this value may cause erratic operation of the on-board regulator and therefore the module itself.
The TX2A incorporates a low voltage shutoff circuit, which prevents any possibility of erratic operation by
disabling the RF output if the supply voltage drops below 2.2V (±5%). This feature is self-resetting, i.e. restoring
the supply to greater than 2.2V will immediately restore full RF output from the module.
The standard RX2G requires a regulated 5V supply with ripple content <100mVpk-pk.
However, a built-in regulator version is also available. The regulator version can be operated from 5V
(minimum) up to 16V (maximum permitted) supply rail and removes the need for external supply decoupling
except in cases where the supply rail is extremely poor (ripple/noise content >0.1Vp-p).
TX2A modulation requirements
The module will produce the specified FM deviation with a TXD input to pin 7 of 2.5V amplitude, i.e. 0V "low",
2.5V "high". Reducing the amplitude of the data input from this value (usually as a result of reducing the supply
voltage) reduces the transmitted FM deviation to typically ±25kHz at the lower extreme of 2.2V. The receiver
will cope with this quite happily and no significant degradation of link performance should be observed as a
result.
Where standard 2-level digital data is employed with a logic "low" level of 0V ±0.2V, the logic "high" level
applied to TXD may be any value between +2.5V and +3V for correct operation. However, if using multi-level or
analogue signalling the maximum positive excursion of the modulation applied to TXD must not exceed +2.5V
or waveform distortion will result. If the input waveform exceeds this level a resistive potential divider should be
used at the TXD input to reduce the waveform amplitude accordingly. This input is high impedance (>100k)
and can usually be ignored when calculating required resistor values.
Received Signal Strength Indicator (RSSI)
The RX2G 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 (~100k) 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, TX2A/RX2G Data Sheet
page 6
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 5: Typical RSSI response
Module mounting considerations
The module may be mounted vertically or bent horizontal to the motherboard. 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
50 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, TX2A/RX2G Data Sheet
page 7
Antenna requirements
Three types of integral antenna are recommended and approved for use with the module:
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.6: Antenna configuration
Features
Ultimate performance
Easy of design set-up
Size
Immunity proximity effects
Range open ground to similar antenna
(for TX2A-433-14-5V & RX2G-433-15-5V)
A
helical
**
**
***
**
200m
B
loop
*
*
**
***
100m
C
whip
***
***
*
*
300m
Antenna selection chart
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
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
Radiometrix Ltd, TX2A/RX2G 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 TX2A-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 TX2A-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 TX2A-433 into their product.
It should be noted that the stated Duty Cycle must not be exceeded otherwise any approval granted for the
TX2A-433 will be invalidated.
Variants and ordering information
The TX2A is manufactured in several variants depending on their supply voltage and operating frequency:
Supply voltage:
3V version:
5V version:
Standard:
TX2A-433-64-3V
TX2A-433-64-5V
TX2A-433-64
Direct replacement for the TX2-433-40-3V
Direct replacement for the TX2-433-40-5V
Different frequency replacement for TX3A
The RX2G receivers are also manufactured in several variants:
Data rate:
Slower version: 7.8kHz baseband B/W, data rate up to 15kb/s
(suffix -15)
Faster version: 50kHz baseband B/W, data rate up to 64kb/s
(suffix -64)
The following variants are standard:
RX2G-433-15-5V-DS
RX2G-433-64-5V-DS
RX2G-433-15-5V
RX2G-433-64-5V
RX2G-433-128-5V
Regulator version:
RX2G-433-15-DS
RX2G-433-64-DS
433.92MHz, 15kbps, Data Slicer for Non-bit balanced data
433.92MHz, 64kbps, Data Slicer for Non-bit balanced data
433.92MHz, 15kbps, Manchester Encoded data packet with preamble
433.92MHz, 64kbps, Manchester Encoded data packet with preamble
433.92MHz, 128kps, Manchester Encoded data packet with preamble
433.92MHz, 15kb/s
433.92MHz, 64kb/s
TX2A/RX2G pair is available on the following frequencies as standard
Frequency:
433.92MHz
(suffix -433)
434.42MHz
(suffix -434)
434.525MHz
(suffix -434.525)
For other frequency variants within 433.05-434.79MHz SRD band, please contact sales department
Evaluation platforms:
1. Universal Evaluation Kit
2. NBEK + SIL carrier
Radiometrix Ltd, TX2A/RX2G Data Sheet
page 9
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/
Information Requests
Ofcom
Riverside House
2a Southwark Bridge Road
London SE1 9HA
Tel: +44 (0)300 123 3333 or 020 7981 3040
Fax: +44 (0)20 7981 3333
[email protected]
European Communications Office (ECO)
Peblingehus
Nansensgade 19
DK 1366 Copenhagen
Tel. +45 33896300
Fax +45 33896330
[email protected]
www.ero.dk
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