SX1231
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
FRC
BRF
BRO
FDA
RC Oscillator frequency
Bit rate, FSK
After calibration
Programmable
Programmable
-
62.5
-
kHz
1.2
1.2
0.6
-
-
-
300
kbps
kbps
kHz
Bit rate, OOK
32.768
300
Frequency deviation, FSK
Programmable
FDA + BRF/2 =< 500 kHz
2.4.3. Receiver
All receiver tests are performed with RxBw = 10 kHz (Single Side Bandwidth) as programmed in RegRxBw, receiving a
PN15 sequence with a BER of 0.1% (Bit Synchronizer is enabled), unless otherwise specified. The LNA impedance is set
to 200 Ohms, by setting bit LnaZin in RegLna to 1, and the AdcLowPowerOn in RegTemp is set to 1. Blocking tests are
performed with an unmodulated interferer. The wanted signal power for the Blocking Immunity, ACR, IIP2, IIP3 and AMR
tests is set 3 dB above the nominal sensitivity level.
Table 6 Receiver Specification
Symbol
Description
Conditions
Min
Typ
Max
Unit
RFS_F
FSK sensitivity, highest LNA gain
-
-
-
-118
-114
-105
-
-
-
dBm
dBm
dBm
FDA = 5 kHz, BR = 1.2 kb/s
FDA = 5 kHz, BR = 4.8 kb/s
FDA = 40 kHz, BR = 38.4 kb/s
-
-
-120
-112
-10
-
-109
-
dBm
dBm
dB
FDA = 5 kHz, BR = 1.2 kb/s *
BR = 4.8 kb/s
RFS_O
OOK sensitivity, highest LNA gain
CCR
ACR
Co-Channel Rejection
-13
Adjacent Channel Rejection
-
37
42
42
-
-
dB
dB
Offset = +/- 25 kHz
Offset = +/- 50 kHz
BI
Blocking Immunity
-
-
-
-45
-40
-32
-
-
-
dBm
dBm
dBm
Offset = +/- 1 MHz
Offset = +/- 2 MHz
Offset = +/- 10 MHz
Blocking Immunity
Wanted signal at sensitivity
+16dB
-
-
-
-36
-33
-25
-
-
-
dBm
dBm
dBm
Offset = +/- 1 MHz
Offset = +/- 2 MHz
Offset = +/- 10 MHz
AMR
AM Rejection , AM modulated
interferer with 100% modulation
depth, fm = 1 kHz, square
-
-
-
-45
-40
-32
-
-
-
dB
dB
dB
Offset = +/- 1 MHz
Offset = +/- 2 MHz
Offset = +/- 10 MHz
IIP2
IIP3
2nd order Input Intercept Point
Unwanted tones are 20 MHz
above the LO
-
-
+75
+35
-
-
dBm
dBm
Lowest LNA gain
Highest LNA gain
3rd order Input Intercept point
Unwanted tones are 1MHz and
1.995 MHz above the LO
-
+20
-18
-
-
dBm
dBm
Lowest LNA gain
Highest LNA gain
-23
BW_SSB
Single Side channel filter BW
Programmable
Page 13
2.6
-
500
kHz
Rev 2 - Nov 2009
www.semtech.com
SEMTECH [ SEMTECH CORPORATION ]
