SM1211E915 Semtech, SM1211E915 Datasheet - Page 23

• Manufacturer Part Number: SM1211E915
• Description: Dev Kit Accessory
• Manufacturer: Semtech

Specifications of SM1211E915

• Modulation Type: FSK, OOK
• Data Rate Max: 200Kbps
• Frequency Range: 902MHz To 928MHz
• Supply Voltage Range: 2.1V To 3.6V
• Module Interface: SPI
• Supply Current: 25mA
• Accessory Type: RF Module
• Sensitivity: -105dBm
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Package Type: TQFN EP
• Operating Supply Voltage (min): 2.1V
• Operating Supply Voltage (typ): 2.5/3.3V
• Operating Supply Voltage (max): 3.6V
• Sensitivity (dbm): -105dBm
• Rohs Compliant: NA
• Lead Free Status / RoHS Status: na
• Lead Free Status / RoHS Status: na

The SX1211 is set to receive mode when MCParam_Chip_mode = 011.
The SX1211 receiver employs a super-heterodyne architecture. Here, the first IF is 1/9
(approximately 100MHz). The second down-conversion down-converts the I and Q signals to base band in the
case of the FSK receiver (Zero IF) and to a low-IF (IF2) for the OOK receiver.
After the second down-conversion stage, the received signal is channel-select filtered and amplified to a level
adequate for demodulation. Both FSK and OOK demodulation are available. Finally, an optional Bit Synchronizer
(BitSync) is provided, to be supply a synchronous clock and data stream to a companion uC in Continuous mode,
Rev 7 – Sept 2
ADVANCED COMMUNICATIONS & SENSING
3.4. Receiver Description
LNA
RF
equal to fo
in FSK
IF2<0
mode
3.4.1. Architecture
nd
, 2008
First down-
conversion
LO1 Rx
in FSK
IF2=0
mode
0
0
down-conversion
Second
down-conversion
Second
IF1
Second down-
≈100MHz
≈100MHz
conversion
LO2
IF1
Rx
IF1
LO2 Rx
LO2 Rx
Figure 16: OOK Receiver Setting
Figure 14: Receiver Architecture
Figure 15: FSK Receiver Setting
RSSI
Page 23 of 92
down-conversion
down-conversion
First
First
Baseband, IF2 in OOK
demod
demod
OOK
FSK
frequency
frequency
Image
Image
synchronizer
Bit
LO1 Rx
LO1 Rx
th
of the RF frequency
Channel
Channel
Control logic
-Pattern recognition
-FIFO handler
-SPI interface
-Packet handler
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SX1211
Frequency
Frequencyl