SI4020-I1-FT Silicon Laboratories Inc, SI4020-I1-FT Datasheet - Page 23

• Manufacturer Part Number: SI4020-I1-FT
• Description: IC TX FSK 915MHZ 5.4V 16-TSSOP
• Manufacturer: Silicon Laboratories Inc

Specifications of SI4020-I1-FT

• Package / Case: 16-TSSOP
• Frequency: 315MHz, 433MHz, 868MHz, and 915MHz
• Modulation Or Protocol: FSK, OOK
• Data Rate - Maximum: 256 kbps
• Current - Transmitting: 14mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 2.2 V ~ 5.4 V
• Operating Temperature: -40°C ~ 85°C
• Operating Frequency: 315 MHz to 915 MHz
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 2.2 V to 5.4 V
• Supply Current: 1.5 mA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Power - Output: -
• Applications: -
• Memory Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1621-5

CRYSTAL SELECTION GUIDELINES
The crystal oscillator of the Si4020 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
crystal, the oscillator is able to start up with any crystal having less than 300 ohms ESR (equivalent series loss resistance). However,
lower C
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: There may be other requirements for the TX carrier accuracy with regards to the requirements as defined by standards and/or channel
Bit Rate: 2.4kbps
Bit Rate: 9.6kbps
Bit Rate: 38.3kbps
separations.
0
and ESR values guarantee faster oscillator startup.
315 MHz
433 MHz
868 MHz
915 MHz
315 MHz
433 MHz
868 MHz
915 MHz
315 MHz
433 MHz
868 MHz
915 MHz
don’t use
don't use
don't use
don't use
30
30
20
10
10
30
25
15
30
8
8
60
75
50
25
25
60
70
50
25
25
60
30
20
10
10
100
100
90
75
40
40
90
75
40
40
90
75
50
30
25
Transmitter Deviation [+/- kHz]
Transmitter Deviation [+/- kHz]
Transmitter Deviation [+/- kHz]
120
100
100
120
100
100
120
100
60
50
60
50
75
40
40
150
100
100
150
100
100
150
100
100
75
75
75
70
60
60
180
100
100
100
180
100
100
180
100
100
75
75
75
75
75
0
) value is expected for the
c
). Therefore, f
0
.
210
100
100
100
100
210
100
100
100
100
210
100
100
100
75
c
Si4020
is directly
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