SI4022-A0-FTR Silicon Laboratories Inc, SI4022-A0-FTR Datasheet - Page 17

• Manufacturer Part Number: SI4022-A0-FTR
• Description: IC TX FSK UNI 868/915MHZ 16TSSOP
• Manufacturer: Silicon Laboratories Inc

Specifications of SI4022-A0-FTR

• Frequency: 868MHz, 915MHz
• Applications: ISM
• Modulation Or Protocol: FSK
• Data Rate - Maximum: 115.2kbps
• Power - Output: 6dBm
• Current - Transmitting: 24mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 2.2 V ~ 3.8 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 16-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Memory Size: -

Note:
Note:
CRYSTAL SELECTION GUIDELINES
The crystal oscillator of the Si4022 requires a 10 MHz parallel mode crystal. The circuit contains an integrated load capacitor in order
to minimize the external component count. The internal load capacitance value is programmable from 8.5 pF to 16 pF in 0.5 pF steps.
With appropriate PCB layout, the total load capacitance value can be 10 pF to 20 pF so a variety of crystal types can be used.
When the total load capacitance is not more than 20 pF and a worst case 7 pF shunt capacitance (C
the oscillator is able to start up with any crystal having less than 300 ohms ESR (equivalent series loss resistance). However, lower
C
low as possible.
The crystal frequency is used as the reference of the PLL, which generates the RF carrier frequency (f
proportional to the crystal frequency. The accuracy requirements for production tolerance, temperature drift and aging can thus be
determined from the maximum allowable carrier frequency error.
Maximum XTAL Tolerances Including Temperature and Aging [ppm]
Whenever a low frequency error is essential for the application, it is possible to “pull” the crystal to the accurate frequency by
changing the load capacitor value. The widest pulling range can be achieved if the nominal required load capacitance of the crystal
is in the “midrange”, for example 16 pF. The “pull-ability” of the crystal is defined by its motional capacitance and C
Note:
Note:
Note: There may be other requirements for the TX carrier accuracy with regards to the requirements as defined by standards and/or
0
and ESR values guarantee faster oscillator startup. It is recommended to keep the PCB parasitic capacitances on the XTL pin as
Bit Rate:
Bit Rate:
Bit Rate:
Bit Rate:
channel separations.
2.4 kbps
9.6 kbps
38.4 kbps
115.2 kbps
868
915
868
915
868
915
868
915
do not use
do not use
do not use do not use
do not use do not use
do not use do not use do not use do not use do not use
do not use do not use do not use do not use do not use
20
20
20
20
2
2
40
40
40
40
12
12
8
8
60
60
60
60
25
20
20
15
10
10
Transmitter Deviation [+/- kHz]
Transmitter Deviation [+/- kHz]
Transmitter Deviation [+/- kHz]
Transmitter Deviation [+/- kHz]
80
80
80
80
30
30
30
30
20
20
100
100
100
100
40
40
40
40
30
30
120
120
120
120
50
50
50
50
40
40
2
2
0
) value is expected for the crystal,
140
140
140
140
c
). Therefore f
60
60
50
50
12
12
70
60
0
.
160
160
160
160
Si4022
80
70
70
70
70
60
25
20
c
is directly
17