
Si4421
Note 1: Measured with disabled clock output buffer
Note 2: Not using a 10 MHz crystal is allowed but not recommended because all crystal referred timing and frequency parameters will change accordingly
Note 3: See the BER diagrams in the measurement results section (page 37) for detailed information
Note 4: See reference design with 50 Ohm Matching Network (page 39) for details
Note 5: See reference design with Resonant PCB Antenna (BIFA) on page 41 for details
Note 6: Optimal antenna admittance/impedance:
Si4421 | Yantenna [mS] | Zantenna [Ohm] | Lantenna [nH] | |
433 MHz | 2 – j5.9 | 52 | + j152 | 62 |
868 MHz | 1.2 - j11.9 | 7.8 + j83 | 15.4 | |
915 MHz | 1.49 - j12.8 | 9 | + j77 | 13.6 |
Note 7: Adjustable in 8 steps
Note 8: During the
Note 9: The crystal oscillator start up time strongly depends on the capacitance seen by the oscillator. Low capacitance and low ESR crystal is recommended with low parasitic PCB layout design.
Note 10: By design
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