RFM63B Datasheet, PDF (66/90 Pages) List of Unclassifed Manufacturers – ISM TRANSCEIVER MODULE V1.1

ADVANCED COMMUNICATIONS & SENSING
RFM63B
7. Application Information
7.1. Crystal Resonator Specification
Table 34 shows the crystal resonator specification for the crystal reference oscillator circuit of the RFM63B.
This specification covers the full range of operation of the RFM63B and is employed in the reference design (see
section
7.5.3).
Table 34: Crystal Resonator Specification
Name
Fxtal
Cload
Rm
Co
Fxtal
Fxtal( T)
Fxtal( t)
Description
Nominal frequency
Load capacitance for Fxtal
Motional resistance
Shunt capacitance
Calibration tolerance at 25+/-3°C
Stability over temperature range [-40°C ; +85°C]
Ageing tolerance in first 5 years
Min.
9
10
-
1
-15
-2 0
-2
Typ.
12.800
15
-
-
-
-
-
Max.
15
16.5
100
7
+15
+20
+2
Unit
MHz
pF
ohms
pF
ppm
ppm
ppm/year
Note that the initial frequency tolerance, temperature stability and ageing performance should be chosen in
accordance with the target operating temperature range and the receiver bandwidth selected.
7.2. Software for Frequency Calculation
The R1, P1, S1, and R2, P2, S2 dividers are configured over the SPI interface and programmed by 8 bits each, at
addresses 6 to 11. The frequency pairs may hence be switched in a single SPI cycle.
7.2.1. GUI
To aid the user with calculating appropriate R, P and S values, software is available to perform the frequency
calculation. The RFM63B PLL frequency Calculator Software can be downloaded from the Semtech website.
7.2.2. .dll for Automatic Production Bench
The Dynamically Linked Library (DLL) used by the software to perform these calculations is also provided, free of
charge, to users, for inclusion in automatic production testing. Key benefits of this are:
• No hand trimming of the reference frequency required: the actual reference frequency of the Device Under Test
(DUT) can be easily measured (e.g. from the CLKOUT output of the RFM63B) and the tool will calculate
the best frequencies to compensate for the crystal initial error.
• Channel plans can be calculated and stored in the application‟s memory, then adapted to the actual crystal
oscillator frequency.
7.3. Switching Times and Procedures
As an ultra-low power device, the RFM63B can be configured for low minimum average power consumption.
To minimize consumption the following optimized transitions between modes are shown.
Page 66 of 90
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