SX1239IMLTRT Semtech, SX1239IMLTRT Datasheet - Page 44

• 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

5.5. Packet Mode
5.5.1. General Description
In Packet mode the NRZ data from the demodulator is not directly accessed by the uC but stored in the FIFO and
accessed via the SPI interface.
In addition, the SX1239 packet handler performs several packet oriented tasks such as Preamble and Sync word check,
CRC check, dewhitening of data, Manchester decoding, address filtering, AES decryption, etc. This simplifies software and
reduces uC overhead by performing these repetitive tasks within the RF chip itself.
Another important feature is ability to empty the FIFO in Sleep/Stdby mode, ensuring optimum power consumption and
adding more flexibility for the software.
Note
5.5.2. Packet Format
5.5.2.1. Fixed Length Packet Format
Fixed length packet format is selected when bit PacketFormat is set to 0 and PayloadLength is set to any value greater
than 0.
In applications where the packet length is fixed in advance, this mode of operation may be of interest to minimize RF
overhead (no length byte field is required). All nodes should be programmed with the same packet length value.
Rev 3 - Jan 2011
ADVANCED COMMUNICATIONS & SENSING
Data
The Bit Synchronizer is automatically enabled in Packet mode.
Rx
SYNC
RECOG.
PACKET
HANDLER
Figure 27. Packet Mode Conceptual View
CONTROL
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FIFO
(+SR)
SPI
DATASHEET
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NSS
SCK
MOSI
MISO
SX1239
DIO3
DIO4
DIO5
DIO0
DIO1
DIO2