SX1232
WIRELESS & SENSING
DATASHEET
3.5. Receiver Description
3.5.1. Overview
The SX1232 features a digital receiver with the analog to digital conversion process being performed directly following the
LNA-Mixers block. The Low-IF receiver is able to handle ASK, OOK, (G)FSK and (G)MSK modulation. All the filtering,
demodulation, gain control, synchronization and packet handling is performed digitally, which allows a very wide range of
bit rates and frequency deviations to be selected. The receiver is also capable of automatic gain calibration to improve
precision on RSSI measurement and enhanced image rejection.
Figure 8. Receiver Block Diagram
3.5.2. Automatic Gain Control - AGC
The AGC feature allows receiver to handle a wide Rx input dynamic range from the sensitivity level up to maximum input
level of 0dBm or more, whilst optimizing the system linearity.
Table 15 hereafter shows typical NF and IIP3 performances for the different LNA gains.
Table 15 LNA Gain Control and Performances
Gain
Setting
Relative LNA
Gain [dB]
NF
[dB]
IIP3
[dBm]
RX input level (Pin)
LnaGain
Pin <= AgcThresh1
G1
G2
G3
G4
G5
G6
‘001’
‘010’
‘011’
‘100’
‘110’
‘111’
0 dB
7
-12
-8
AgcThresh1 < Pin <= AgcThresh2
AgcThresh2 < Pin <= AgcThresh3
AgcThresh3 < Pin <= AgcThresh4
AgcThresh4 < Pin <= AgcThresh5
AgcThresh5 < Pin
-6 dB
11
16
26
34
44
-12 dB
-24 dB
-26 dB
-48 dB
-5
5
10
10
Rev 3 - August 2012
Page 27
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