AN296 Silicon_Laboratories, AN296 Datasheet - Page 21

• Manufacturer Part Number: AN296
• Description: Using THE Si3400 AND Si3401 POE PD Controllers IN Isolated AND Non-isolated Designs
• Manufacturer: Silicon_Laboratories

Figure 17 is the measured conducted emissions result. For the grounded-output case, a common-mode choke,
such as the Coilcraft BU9-2820R5BL, is required due to a possible ground loop.
7.5. Minimum Load Considerations
To ensure the switcher does not pulse on and off when no load is on the output, Silicon Labs recommends a
≥250 mW load be present. See "3.4. Maintain Power Signature" on page 7 for more information.
8. Conclusion
This application note has covered the basic operation and design equations for the Si3400/01, allowing the design
of highly-integrated and efficient PDs for PoE applications.
As mentioned earlier, reference designs and design spreadsheets are also available at www.silabs.com/PoE to
assist in the easy design-in process for the Si3400/01. The spreadsheets should be used in conjunction with this
application note, and additional documentation is included within the spreadsheet. The evaluation boards and
reference designs are documented separately and include example layouts and BOM lists.
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Figure 17. Conducted Emissions Test Result
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AN296
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