SI4420 Datasheet, PDF (10/33 Pages) Silicon Laboratories – No alignment required in production

Si4420
AC Characteristics (continued)
Note 1: Not using a 10 MHz crystal is allowed but not recommended because all crystal referred timing and frequency parameters will
change accordingly.
Note 2: See the BER diagrams in the measurement results section for detailed information (Not available at this time).
Note 3: See matching circuit parameters and antenna design guide for information.
Note 4: Optimal antenna admittance/impedance:
Si4420
315 MHz
433 MHz
868 MHz
915 MHz
Yantenna [S]
1.5E-3 - j5.14E-3
1.4E-3 - j7.1E-3
2E-3 - j1.5E-2
2.2E-3 - j1.55E-2
Zantenna [Ohm]
52 + j179
27 + j136
8.7 + j66
9 + j63
Lantenna [nH]
98.00
52.00
12.50
11.20
Note 5: Adjustable in 8 steps.
Note 6: With selective resonant antennas (see: Application Notes available from www.silabs.com/integration).
Note 7: During this period, commands are not accepted by the chip. For detailed information see the Reset modes section.
Note 8: The crystal oscillator start-up time strongly depends on the capacitance seen by the oscillator. Using low capacitance and low ESR
crystal is recommended. When designing the PCB layout keep the trace connecting to the crystal short to minimize stray
capacitance.
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