XE1202AI027TRLF Semtech, XE1202AI027TRLF Datasheet - Page 9

• Manufacturer Part Number: XE1202AI027TRLF
• Description: Narrow Band 433/868/915MHz RF Transceiver
• Manufacturer: Semtech

When “RTParam_Bits” is set to “0”, the bit synchronizer is turned off, and DATAOUT is the output of the
demodulator. In this case DCLK is not used and its value is set “low”.
For guaranteed operation of the demodulator, the modulation index, β, of the modulated carrier should meet the
following condition:
where ∆f is the frequency deviation, and BR the bit rate.
Table 5 details typical sensitivity figures for different bit rates, frequency deviations and baseband filter bandwidths:
Figure 2 illustrates the typical BER curve under narrowband conditions:
4.1.2
The receiver can be operated in two different modes that provide the highest sensitivity (for reception of weak
signals) or the highest linearity (in areas of strong signals). The receiver mode is determined by the programming of
the “
A-mode: high sensitivity mode (see RFS parameter)
B-mode: high linearity mode (see IIP3 parameter)
© Semtech 2006
RTParam_Rmode
Receiver LNA modes
” register (see the Configuration register section below).
Figure 2: BER versus Rx input power with BR=4.8 kbits/s, ∆f=5 kHz, BW=10 kHz
β
=
BER
2
Bit rate
[kbits/s
]
4.8
9.6
19.2
38.4
76.8
BR
∆ ⋅
10 -2
10 -3
10 -4
10 -5
10 -6
f
-116 -115 -114 -113 -112 -111 -110 -109
≥
, 2
∆f
[kHz]
5
20
10
20
20
40
40
100
100
10
BW
[kHz]
10
40
20
40
40
200
200
200
200
RX in mode A
Pin [dBm]
Table 5: Sensitivity for 1 % BER
Sensitivity for 1 % BER
[dBm]
mode A
-116
-117
-115
-115.5
-112.5
-109
-107
-109
-106.5
XE1202A TrueRF™
mode B
-103
-104
-101
-102.5
-99.5
-97.5
-95
-97.5
-95
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