ER900TS EASY RADIO, ER900TS Datasheet - Page 19

• Manufacturer Part Number: ER900TS
• Description: MODULE, TX, FM, 860-920MHZ
• Manufacturer: EASY RADIO

Specifications of ER900TS

• External Depth: 3.8mm
• External Length / Height: 12.5mm
• External Width: 32mm
• Frequency: 868MHz
• Operating Temperature Max: 65°C
• Operating Temperature Min: -20°C
• Output Power: 10mW
• Range: 150m

Notes:
RSSI Output
The Receiver/Transceiver has a built in RSSI (Received Signal Strength Indicator) that provides an analogue
output voltage that is inversely proportional to the RF energy present within the pass band of the receiver. It
ranges from 0 Volt (maximum signal, –65dBm) to 1 Volt (minimum signal, -115bBm) and has a slope of
approximately 50dB/Volt. This analogue output signal should only be connected to a high impedance load
(>100kΩs) and can be used to provide a measure of the signal strength and any interfering signals (noise)
within band during the installation and operation of systems.
Application Notes
Compatibility
The ERx00TS, ERx00RS & ERx00TRS use crystal controlled synthesisers to accurately define transmit and
receive frequencies incorporating RS232 protocols, and so should not be used in connection with Non-Easy
Radio RF modules unless the firmware allows.
LPRS Data Sheet
ERx00-02 Series V2.3
DATA OUT
HOST RDY
Antenna
DATA IN
RF GND
RSSI
BUSY
ANT
VCC
GND
Host Ready Tied Low
1
2
3
4
5
6
7
8
9
100n
Datasheet Revision 2.3 Sept 2005
+5V
1.3
1.2
1.1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
1
0
-115
-110
ER400TS Transmitter, ER400RS Receiver & ER400TRS Transceiver
ER900TS Transmitter, ER900RS Receiver & ER900TRS Transceiver
-105
1
2
3
4
5
6
7
8
Figure 11 MAX232 Application Circuit
-100
C1+
V+
C1-
C2+
C2-
V-
T2OUT
R2IN
Received Signal Strength (dBm)
MAX232
T1OUT
R1OUT
R2OUT
Easy-Radio ‘02’ (2
Figure 10 RSSI Output
MAX232 Application
-95
R1IN
T1IN
T2IN
VCC
GND
16
15
14
13
12
11
10
9
-90
-85
100n
Copyright LPRS 2005.
-80
nd
100n
Generation Modules)
-75
VO
7805
G
N
D
-70
VI
-65
100n
Vin = 8-12V DC
0 Volt
1
6
2
7
3
8
4
9
5
1N4148
433Mhz
868MHz
PC AT
DCD
DSR
RXD
RTS
TXD
CTS
DTR
RI
GND
Page 19 of 30