RADIOMETRIX RX3G

Radiometrix
Hartcran House, 231 Kenton Lane, Harrow, HA3 8RP, England
Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233
RX3G
Issue 2, 13 November 2012
UHF FM receiver module with RSSI
The RX3G is a PLL synthesiser based
miniature PCB mounting UHF radio
data receiver.
With
the
matching
TX3B-869-64
transmitters, RX3G allows the simple
implementation of wireless data links
at speeds up to 64kbps and distances up
to 75 metres in-building or 300 metres
over open ground.
Fig 1: RX3G-869.85-64
Features:
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Designed to comply with harmonised radio standard EN 300 220-3
Designed to comply with harmonised EMC standard EN 301 489-3
North American version conforms to FCC part 15.249
Data rates up to 128kbps
Usable range up to 300m
Versions available on 868.3MHz, 869.5MHz, 869.85MHzn and
Regulated and Unregulated versions available
Fully screened
Improved blocking performance
Fast data settling time
Available for operation at 868.3MHz, 869.5MHz and 869.85MHz in Europe, the RX3G
combines full screening with internal filtering to ensure EMC compliance by minimising
spurious radiation and susceptibility. The module suits 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 the small size and
low power requirements, the RX3G is ideal for use in portable, battery-powered wireless
applications such as hand-held terminals.
Technical Summary
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Single conversion FM superhet
SAW front end filter gives >50dB image rejection
Supply: +5V (± 10%)
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
RX3G data sheet
page 1
Pin description
RF IN
(pin 1)
50 input from the antenna, DC
isolated.
RF GND
(pin 2)
RF
ground
pin,
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.)
Fig 2: physical dimensions & pin outs
RF GND
(pin 3)
Not fitted on non-regulator 5V variant
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.
0V
(pin 6)
DC supply ground. Internally connected to pin 2/3 and module screen.
Vcc (5V variant)
(pin 7)
Externally regulated 5V DC supply. Max ripple content 0.1Vp-p.
Vcc (for regulator variant)
(pin 7)
5.1V to +16V 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
RX3G data sheet
page 2
Absolute maximum ratings
Exceeding the values given below may cause permanent damage to the module.
Operating temperature
-20C to +70C
Storage temperature
-40C to +100C
Vcc (pin 7)
-0.1V to +5.5V
RSSI, AF, RXD (pins 5,8,9) -0.1V to +3V
RF IN (pin 1)
50V DC, +10dBm RF
Performance specifications
(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/ IF
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
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
3,5
3,9
3,9
3,9
-
0.5
6
1.5
10
1
ms
ms
ms
ms
1,5
1,9
1,9
1,9
-
100
0.5
5
0.2
1
μs
ms
0.5
ms
DC supply
Supply voltage
Supply voltage (regulator ver.)
Supply current
Signal applied with supply on
RSSI response time (rise/fall)
Signal to stable data
Signal to stable data
Signal to stable data
Signal to stable data
Time between data transitions
15kbps version
64kbps version
15kbps version
64kbps version
2
3
3
3, 15kbps version
3, 64kbps version
3, -DS version
3, 15kbps
3, 15kbps DS
3, 64kbps
3, 64kbps DS
0.0667
1.5
ms
4, 15kbps
0.0667
75
ms
4, 15kbps DS
Time between data transitions
9
0.0156
0.2
ms
4, 64kbps
0.0156
3
ms
4, 64kbps DS
Mark:space ratio
9
20
50
80
%
5
Notes:
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
9
RX3G data sheet
page 3
Power supply requirements
The standard RX3G requires a regulated 5V supply with ripple content <100mVpk-pk
However, built-in regulator in the regulator version RX3G delivers a constant 5V to the
module circuitry when the external supply voltage is 5V or greater, with 40dB or more of
supply ripple rejection. This ensures constant performance up to the maximum permitted
supply rail (16V max.) 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 5V 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 low-ESR 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.
Received Signal Strength Indicator (RSSI)
The module incorporates a wide range RSSI which measures the strength of an incoming
signal over a range of approximately 50dB. This allows assessment of link quality and
available margin and is useful when performing range tests.
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 10nF 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, in the form of a capacitor from pin 5 to ground, at
the expense of response speed.
Typical RSSI characteristic is as shown below:
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)
Radiometrix Ltd
RX3G data sheet
page 4
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 0V 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.
Variants and ordering information
The RX3G receivers are manufactured in several variants:
Data rate:
Slower version:
Faster version:
Frequency: 868.30MHz
869. 50MHz
869.85MHz
914.50MHz
7.8kHz baseband B/W,
(suffix -15)
50kHz baseband B/W,
(suffix -64)
50kHz baseband B/W,
(suffix -128)
data rate up to 15kb/s
data rate up to 64kb/s
data rate up to 128kb/s
(suffix –868.30)
(suffix -869.50)
(suffix –869.85)
(suffix –914.50)
The following data rate variants are standard:
RX3G-869.85-15-5V-DS
RX3G-869.85-64-5V-DS
869.85MHz, 15kb/s Data Slicer for Non-bit balanced data
869.85MHz, 64kb/s Data Slicer for Non-bit balanced data
RX3G-869.85-15-5V
RX3G-869.85-64-5V
869.85MHz, 15kb/s Manchester Encoded data packet with preamble
869.85MHz, 64kb/s Manchester Encoded data packet with preamble
RX3G-869.85-128-5V
869.85MHz, 128kb/s
Regulator version:
RX3G-869.85-15-DS
RX3G-869.85-64-DS
RX3G-869.85-128
869.85MHz, 15kb/s
869.85MHz, 64kb/s
869.85MHz, 128kb
Matching Transmitters:
TX3B-869.85-64
869.85MHz
For other variants please contact the sales department
Evaluation platforms:
1. Universal Evaluation Kit
2. NBEK + SIL carrier
Radiometrix Ltd
RX3G data sheet
page 5
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 wireless 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