Datasheet

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SX1272/73
WIRELESS, SENSING & TIMING DATASHEET
Rev. 2 - July 2014
©2014 Semtech Corporation
5.5.6. Channel Filter
The role of the channel filter is to reject noise and interference outside of the wanted channel. The SX1272/73 channel
filtering is implemented with a 16-tap finite impulse response (FIR) filter. Rejection of the filter is high enough that the filter
stop-band performance is not the dominant influence on adjacent channel rejection performance. This is instead limited by
the SX1272/73 PLL phase noise.
Note To respect sampling criterion in the decimation chain of the receiver, the communication bit rate cannot be set at a
higher than twice the single side receiver bandwidth (BitRate < 2 x RxBw)
The programmed single side bandwidth RxBw of the channel filter is determined by the parameters RxBwMant and
RxBwExp in RegRxBw:
The following channel filter bandwidths are hence accessible in the case of a 32 MHz reference oscillator.
Table 38 Available RxBw Settings
5.5.7. Temperature Measurement
A stand alone temperature measurement block is used in order to measure the temperature in all mode except Sleep and
Standby. It is enabled by default and can be stopped by setting TempMonitorOff to 1. The result of the measurement is
stored in TempValue in RegTemp.
RxBwMant
(binary/value)
RxBwExp
(decimal)
RxBw (kHz)
FSK / OOK
10b / 24 7 2.6
01b / 20 7 3.1
00b / 16 7 3.9
10b / 24 6 5.2
01b / 20 6 6.3
00b / 16 6 7.8
10b / 24 5 10.4
01b / 20 5 12.5
00b / 16 5 15.6
10b / 24 4 20.8
01b / 20 4 25.0
00b / 16 4 31.3
10b / 24 3 41.7
01b / 20 3 50.0
00b / 16 3 62.5
10b / 24 2 83.3
01b / 20 2 100.0
00b / 16 2 125.0
10b / 24 1 166.7
01b / 20 1 200.0
00b / 16 1 250.0
Other settings reserved
RxBw
FXOSC
RxBwMant 2
RxBwExp 2+
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