SX1231 SEMTECH [Semtech Corporation], SX1231 Datasheet - Page 65

• Manufacturer Part Number: SX1231
• Description: Low Power Integrated UHF Transceiver
• Manufacturer: SEMTECH [Semtech Corporation]

Rev 2 - Nov 2009
ADVANCED COMMUNICATIONS & SENSING
RegRxBw
(0x19)
RegAfcBw
(0x1A)
RegOokPeak
(0x1B)
RegOokAvg
(0x1C)
RegOokFix
(0x1D)
7-5
4-3
2-0
7-5
4-3
2-0
7-6
5-3
2-0
7-6
5-0
7-0
DccFreq
RxBwMant
RxBwExp
DccFreqAfc
RxBwMantAfc
RxBwExpAfc
OokThreshType
OokPeakTheshStep
OokPeakThreshDec
OokAverageThreshFilt
-
OokFixedThresh
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
r
Page 65
000000 unused
(6dB)
011 *
0110
010
101
100
000
000
10
01
01
10
*
*
*
Cut-off frequency of the DC offset canceller (DCC):
~4% of the RxBw by default
Channel filter bandwidth control:
00
01
Channel filter bandwidth control:
FSK Mode:
OOK Mode:
See Table 13 for tabulated values
DccFreq parameter used during the AFC
RxBwMant parameter used during the AFC
RxBwExp parameter used during the AFC
Selects type of threshold in the OOK data slicer:
00
01
Size of each decrement of the RSSI threshold in the OOK
demodulator:
000
010
100
110
Period of decrement of the RSSI threshold in the OOK
demodulator:
000
010
100
110
Filter coefficients in average mode of the OOK
demodulator:
00
01
10
11
Fixed threshold value (in dB) in the OOK demodulator.
Used when OokThresType = 00
f
RxBwMant = 16
RxBwMant = 20
fixed
peak
f
f
f
C
C
C
C
8 times in each chip
0.5 dB
1.5 dB
3.0 dB
once per chip
once every 4 chips
twice in each chip
5.0 dB
≈ chip rate / 2.π
≈ chip rate / 32.π
≈ chip rate / 8.π
≈ chip rate / 4.π
RxBw
RxBw
fc
=
=
----------------------------------------------------------------- -
RxBwMant 2
----------------------------------------------------------------- -
RxBwMant 2
=
10
11
111
001
011
101
----------------------------------------- -
2 π 2
×
4 RxBw
×
average
reserved
DccFreq
FXOSC
FXOSC
2.0 dB
1.0 dB
4.0 dB
6.0 dB
101
111
001
011
10
11
×
×
RxBwExp
RxBwExp
+
reserved
RxBwMant = 24
16 times in each chip
2
4 times in each chip
once every 2 chips
once every 8 chips
DATASHEET
www.semtech.com
SX1231
+
+
2
3