AN851 Datasheet, PDF (15/25 Pages) Silicon Laboratories – Si468X SCHEMATICS AND LAYOUT GUIDE

The following is the vendor information for the above transformer:
Vendor #1:
Jiaxin Dianzi
Guangzhou Jiaxin Electronics Shenzhen Sales Office
email:
[e-mail]
Web:
www.firstantenna.com
Vendor #2:
UMEC USA, Inc.
Website: www.umec-usa.com
www.umec.com.tw
6.2. Air Loop Antenna Schematic
AN851
Figure 10. AM Air Loop Antenna Schematic
D1 is a required ESD diode since the antenna is exposed.
6.3. Air Loop Antenna Bill of Materials
Designator
LOOP_ANTENNA
T1
Table 7. Air Loop Antenna Bill of Materials
Description
Air loop antenna
Transformer, 1:6 turns ratio
Note
D1
ESD diode, IC, SM, SOT23-3,
California Micro Devices, CM1213-01ST
6.4. Air Loop Antenna Layout
Place the chip and the transformer as close as possible to the air loop antenna feedline. This will minimize the
trace going to the air loop antenna which in turn will minimize parasitic capacitance and the possibility of noise
coupling.
When an air loop antenna with a transformer is used with the Si468x, minimize inductive coupling by making sure
that the transformer is placed away from all sources of interference. Keep the transformer away from signals on the
PCB and away from even the I/O signals of the Si468x. Do not route any signals under or near the transformer.
Use a shielded transformer if possible.
Rev. 0.2
15