SX1239IMLTRT Semtech, SX1239IMLTRT Datasheet - Page 27

• Manufacturer Part Number: SX1239IMLTRT
• Description: IC, RF RECEIVER, 1.02GHz, QFN-24
• Manufacturer: Semtech

Specifications of SX1239IMLTRT

• Applications: Wireless Sensor Networks, Automated Meter Reading, Home And Building Automation
• Receiving Current: 16mA
• Data Rate: 300Kbps
• Modulation Type: FSK, OOK
• Sensitivity Dbm: -120dBm
• Rohs Compliant: Yes
• Rf Ic Case Style: QFN
• No. Of Pins: 24
• Sensitivity (dbm): -120dBm
• Supply Voltage Range: 1.8V To 3.6V
• Operating Temperature Range: -40°C To +85°C
• Lead Free Status / Rohs Status: Supplier Unconfirmed

signed result is loaded in FeiValue in RegFei, in 2’s complement format. The time required for an FEI evaluation is 4 times
the bit period.
To ensure a proper behavior of the FEI:
The 20 dB bandwidth of the signal can be evaluated as follows (double-side bandwidth):
The frequency error, in Hz, can be calculated with the following formula:
3.4.16. Automatic Frequency Correction
The AFC is based on the FEI block, and therefore the same input signal and receiver setting conditions apply. When the
AFC procedure is done, AfcValue is directly subtracted to the register that defines the frequency of operation of the chip,
F
Rev 3 - Jan 2011
ADVANCED COMMUNICATIONS & SENSING
RF
The operation must be done during the reception of preamble
The sum of the frequency offset and the 20 dB signal bandwidth must be lower than the base band filter bandwidth
Each time the receiver is enabled, if AfcAutoOn = 1
Upon user request, by setting bit AfcStart in RegAfcFei, if AfcAutoOn = 0
. The AFC can be launched:
Preamble-modulated input signal
Figure 11. FEI Process
BW
Signal level > Sensitivity
FEI
SX1239 in Rx mode
20 dB
Set FeiStart
Yes
=
FeiValue
FeiDone
F
=
Read
= 1
= 1
Page 27
STEP
2
×
⎛
⎝
×
F
FeiValue
DEV
No
+
BR
------ -
2
⎞
⎠
DATASHEET
www.semtech.com
SX1239