I have concern Switching frequency of TPS61032 interfere AM radio band.
Could you advice how to resolve EMC issue?
for example, snubber circuit, shield, filter, etc
Hi Sir,
Thanks for reaching out. Do you mean the frequency band of 525–1606.5 kHz, 525–1705 kHz, so the AM radio band? TPS61032 could have switching frequency between 500kHz and 700kHz, which falls inside the band you mentioned.
There are several things needed to be consider to mitigate EMI:
1.Snubber circuitry
SW node can be a big EMI source for any DCDC converters. It is mainly formed by switching frequency and also combines normally >10MHz ringing. Add snubber could help mitigate EMI;
See the app note for reference of how to design snubber circuitry
2.Output ripples
Boost converter has output ripple of switching frequency; If there is sensitive circuitry connecting to VOUT directly, it could be interfaced. Use 2nd L-C filter or LDO can be a good way to mitigate this.
See the app note for understanding of output ripple regarding boost converter; For design, you can refer to datasheet 11.2.2.4.2
3.Layout
Layout is of vital importance and should be really taken care of. The SW node combines mainly switching frequency and any sensitive circuitry should keep away;
SW->VOUT->COUT->GND loop should be as small as possible to minimize parasitic from influencing boost operation and can also decrease EMI;
You can refer to the app note for design of boost converter,
-Wenhao
