SM1211E915 Semtech, SM1211E915 Datasheet - Page 30

• 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 new floor threshold value found during this test should be the value used for OOK reception with those receiver
settings.
Note that if the output signal on DATA is logic “1”, the value of MCParam_OOK_floor_thres is below the noise floor
of the receiver chain. Conversely, if the output signal on DATA is logic “1”, the value of MAParam_floor_thres is
several dB above the noise floor.
A sudden drop in signal strength can cause the bit error rate to increase. For applications where the expected
signal drop can be estimated the following OOK demodulator parameters RXParam_OOK_thresh_step and
RXParam_OOK_thresh_dec_period can be optimized as described below for a given number of threshold
decrements per bit RXParam_OOK_thresh_dec_period:
For each decrement of RXParam_OOK_thresh_step:
Rev 7 – Sept 2
ADVANCED COMMUNICATIONS & SENSING
000
001
010
011
100
101
110
111
000
001
010
011
100
101
110
111
once in each chip period (d)
once in 2 chip periods
once in 4 chip periods
once in 8 chip periods
twice in each chip period
4 times in each chip period
8 times in each chip period
16 times in each chip period
0.5 dB (d)
1.0 dB
1.5 dB
2.0 dB
3.0 dB
4.0 dB
5.0 dB
6.0 dB
nd
, 2008
3.4.10.2. Optimizing OOK Demodulator Response for Fast Fading Signals
MCParam_OOK_floor_thres
Figure 23: Floor Threshold Optimization
Increment
Page 30 of 92
Default RXParam_OOK_thresh setting
Adjust Bit Rate, Channel filter BW
Set SX1211 in OOK Rx mode
Monitor DATA pin (pin 20)
Optimization complete
Continuous Mode
No input signal
Glitch activity
on DATA ?
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SX1211