AUREL RX-AM4SF Instruction Manual

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RX-AM4SF

Instruction Manual

RX-AM4SF Receiver

The super-heterodyne receiver RX-AM4SF can provide a RSSI output indicating the amplitude of
the received signal: this output can be used to create a field-strength meter capable to indicate the
distance of the transmitting unit.
Furthermore the RX-AM4SF allows you to select the sensitivity level at which the module must
operate: setting it in a low-sensitivity condition (- 90 dBm) the receiver provides at the RSSI output
a proximity indication, that is not possible at high sensitivity due to the unavoidable saturation of
the receiver; this feature can be useful when you intend to realize equipments for access control
where, besides an identification code, you must also recognize the distance of the transmitter from
the opening under control.

Pin-out

Lot (Week/Year)
Code

Connections

Pin 1
Pin 2-7
Pin 3
Pin 15
Pin 11

Pin 13
Pin 14

+V Preamp
Ground
Antenna
+V
Gain

RSSI output
Data output

15

1

Positive voltage supply +5V ± 5%.
GND
Antenna input, impedance 50 ohm

Positive voltage supply +5V ± 5%.
Sensitivity Level Selection:
Logic level 0 : -109 dBm.
Logic level 1 : -90 dBm.
Output RSSI proportional to the amplitude of the input signal.
Data output from the receiver.

Le caratteristiche tecniche possono subire variazioni senza preavviso. La AUREL S.p.A non si assume la responsabilità di danni causati dall’uso improprio del dispositivo.

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Tel.: [phone] Fax: [phone]

http://www.aurelwireless.com - email: [e-mail]

15/02/2005AUREL S.p.A. Via Foro dei Tigli, 4 - 47015 Modigliana (FC) – ITALY

Pag 1 di 6

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x

A

r

r

r

RX-AM4SF

Instruction Manual

Technical Features

Reception frequency
Supply Voltage Vs
Supply Current
RF Sensitivity
RF passing band at –3dB
IF passing band at –3dB
Interference rejection at ±10MHz
Output square wave
Logic level “0”
Logic level “1”
Spurious RF emission in antenna
Switch-on time
Operating temperature range

Dimensions

Note1:
Note2:
Note3:

power supply is applied.

Note4:

t

Values have been obtained by applying the test system as Fig.1, with a square wave 99% as modula ion index.
The RF emission measu ement has been obtained by connecting the spectrum analyser direc ly to the RX pin 3.
By switch on time is meant the time required by the receiver to acquire the declared characteristics from the very moment the

Values obtained with 10KΩ maximum load applied.

r t

The declared technical characteristics have been obtained by using the following test system:

Fig. 1

RF Generator: frequency 433.92 MHz

Out Level –88dBm

Digital Encode

MC 145026

Min Typ Max Unit Notes

433.92 MHz

4.75 5 5.25 V

6.5 mA

-108 -109 -111 dBm See note 1
600 KHz
300 KHz
dB
2 3 KHz
gnd+0.4 V See note 4

Vs-0,4V V See note 4

-60 dBm See note 2
0,2 s See note 3

-20 +80

°C

See Fig.5

40.13 x 17.5 x 5.5 mm

Modulato

OOK [-2dB]

Pin 3

R

AM4SF

ttenuato

-10dB

Pin 14

Code

Validation

Decoder

MC 145028

Le caratteristiche tecniche possono subire variazioni senza preavviso. La AUREL S.p.A non si assume la responsabilità di danni causati dall’uso improprio del dispositivo.

---------------------------------------------------------------------------------------------------------------------------------------------------------------------

Tel.: [phone] Fax: [phone]

http://www.aurelwireless.com

- email: [e-mail]

15/02/2005AUREL S.p.A. Via Foro dei Tigli, 4 - 47015 Modigliana (FC) – ITALY

Pag 2 di 6

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RX-AM4SF

Instruction Manual

Pin.13 “RSSI” Output

In fig.2 it is reported grafically the behaviour of the voltage at the RSSI output in function of the
power of the input signal, in High Gain mode (pin 11 at logic level 0). In fig 3 it is shown the
equivalent diagram but in Low Gain mode (pin 11 at logic level 1).
Both the diagrams have been obtained experimentally applying at the RF input (pin 3) of the
receiver a square wave AM-modulated, with a modulation index of 99%, drawn directly from a
signal generator, and connecting a 10uF capacitor between the pin 11 and GND .

RSSI Output

2,80
2,60
2,40
2,20
2,00
1,80

RSSI Level (V)

-110 -100 -90 -80 -70 -60 -50

1,60
1,40
1,20
1,00

Received Power (dBm)

Fig. 2 : RSSI output with high gain

RSSI Output

RSSI Level (V)

-100 -90 -80 -70 -60 -50 -40 -30

Received Power (dBm)

Fig. 3 : RSSI output with low gain

2,80

2,60

2,40

2,20

2,00

1,80

1,60

1,40

1,20

1,00

Le caratteristiche tecniche possono subire variazioni senza preavviso. La AUREL S.p.A non si assume la responsabilità di danni causati dall’uso improprio del dispositivo.

---------------------------------------------------------------------------------------------------------------------------------------------------------------------

Tel.: [phone] Fax: [phone]

http://www.aurelwireless.com

- email: [e-mail]

15/02/2005AUREL S.p.A. Via Foro dei Tigli, 4 - 47015 Modigliana (FC) – ITALY

Pag 3 di 6

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RX-AM4SF

Instruction Manual

Device usage

In order to take advantage of the performances described in the technical specifications and to
comply with the operating conditions which characterize the Certification, the receiver has to be
fitted on a printed circuit, considering what follows:

5 V dc supply:

1. The receiver must be supplied by a very low voltage source, safety protected against short
circuits.

2. Maximum voltage variations allowed: ± 0,25 V.

3. De-coupling, next to the receiver, by means of a minimum 100.000 pF. ceramic capacitor.

Ground:

1. It must surround at the best the welding area of the receiver. The circuit must be double layer,
with throughout vias to the ground planes, approximately each 15 mm.

2. It must be properly dimensioned, specially in the antenna connection area, in case a radiating
whip antenna is fitted in it (an area of approximately 50 mm radius is suggested.)

Fig.3 Suggested lay-out for the device correct

usage

50 Ohm line:

1. It must be the shortest as possible.

2. 1,8 mm wide for 1 mm thick FR4 printed circuits and 2,9 mm wide for 1,6 mm thick FR4
printed circuits. On the same side, it must be kept 2 mm away from the ground circuit.

3. On the opposite side a ground circuit area must be present.

Le caratteristiche tecniche possono subire variazioni senza preavviso. La AUREL S.p.A non si assume la responsabilità di danni causati dall’uso improprio del dispositivo.

---------------------------------------------------------------------------------------------------------------------------------------------------------------------

Tel.: [phone] Fax: [phone]

http://www.aurelwireless.com

- email: [e-mail]

15/02/2005AUREL S.p.A. Via Foro dei Tigli, 4 - 47015 Modigliana (FC) – ITALY

Pag 4 di 6

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RX-AM4SF

Instruction Manual

Antenna connection:

1. It may be utilized as the direct connection point for the radiating whip antenna.

2. It can bear the connection of the central wire of a 50 Ω coaxial cable. Be sure that the braid is
welded to the ground in a close point.

Antenna

1. A whip antenna, 16,5 mm long and approximately 1 mm dia, brass or copper wire made, must
be connected to the RF input of the receiver.

2. The antenna body must be keep straight as much as possible and it must be free from other
circuits or metal parts (5 cm minimum suggested distance.)

3. It can be utilized both vertically or horizontally, provided that the connection point between
antenna and receiver input, is surrounded by a good ground plane.

N.B: As an alternative to the a.m. antenna it is possible to utilize the whip model manufactured by
Aurel (see related Data Sheet ed Application Notes).
By fitting whips too different from the described ones, the EEC Certification is not assured.

Other components:

1. Keep the receiver separate from all other components of the circuit (more than 5 mm).

2. Keep particularly far away and shielded all microprocessors and their clock circuits.

3. Do not fit components around the 50 Ohm line. At least keep them at 5 mm distance.

If the Antenna Connection is directly used for a radiating whip connection, keep at least a 5
cm radius free area. In case of coaxial cable connection 5 mm radius will suffice.

Reference Rules

The RX-AM4SF receiver is EEC certified and in particular it complies with the European set of
Rules EN 300 220-3 for class 2, and EN 300 683 for class 1. The equipment has been tested
according to rule EN 60950 and it can be utilized inside a special insulated housing that assures the
compliance with the above mentioned rule. The receiver must be supplied by a very low voltage
safety source protected against short circuits The use of the receiver module is foreseen inside
housings that assure the overcoming of the provision EN 61000-4-2 not directly applicable to the
module itself. In particular, it is at the user’ s care the insulation of the external antenna connection,
and of the antenna itself since the RF output of the receiver is not built to directly bear the
electrostatic charges foreseen by the a.m. provision.

Le caratteristiche tecniche possono subire variazioni senza preavviso. La AUREL S.p.A non si assume la responsabilità di danni causati dall’uso improprio del dispositivo.

---------------------------------------------------------------------------------------------------------------------------------------------------------------------

Tel.: [phone] Fax: [phone]

http://www.aurelwireless.com

- email: [e-mail]

15/02/2005AUREL S.p.A. Via Foro dei Tigli, 4 - 47015 Modigliana (FC) – ITALY

Pag 5 di 6

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RX-AM4SF

Instruction Manual

Reference curves

Current Supply

8,00 mA

7,00 mA

6,00 mA

5,00 mA

4,00 mA

-40 °C -20 °C 0 °C 20 °C 40 °C 60 °C 80 °C 100 °C

Sensibilità

-105 dBm

-103 dBm

-101 dBm

-99 dBm

-97 dBm

-95 dBm

-93 dBm

-91 dBm

-40 °C -20 °C 0 °C 20 °C 40 °C 60 °C 80 °C 100 °C

Fig. 5: Voltage Supply 5V, Frequency 433,92 MHz

Le caratteristiche tecniche possono subire variazioni senza preavviso. La AUREL S.p.A non si assume la responsabilità di danni causati dall’uso improprio del dispositivo.

---------------------------------------------------------------------------------------------------------------------------------------------------------------------

Tel.: [phone] Fax: [phone]

http://www.aurelwireless.com

- email: [e-mail]

15/02/2005AUREL S.p.A. Via Foro dei Tigli, 4 - 47015 Modigliana (FC) – ITALY

Pag 6 di 6