AN851 Datasheet, PDF (16/25 Pages) Silicon Laboratories – Si468X SCHEMATICS AND LAYOUT GUIDE

AN851
6.5. Air Loop Antenna Design Checklist
 Select a shielded transformer or a toroidal shape transformer to prevent noise pickup from interfering sources
 Select a high-Q transformer with coupling coefficient as close to 1 as possible
 Use multiple strands Litz wire for the transformer winding
 Place the transformer away from any sources of interference and even away from the I/O signals of the Si468x.
Please make sure that the AM antenna is as far away as possible from circuits that switch at a rate which falls in
the AM band (520–1720 kHz).
 Select ESD diode D1 with minimum capacitance.
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Rev. 0.2