SLYY200A April   2021  – December 2023 LM25149 , LM25149-Q1 , LM5156-Q1 , LM5157-Q1 , LM53635-Q1 , LM60440-Q1 , LM61460-Q1 , LM61495-Q1 , LMQ62440-Q1 , LMR33630-Q1 , LMS3655-Q1 , TPS55165-Q1 , UCC12040 , UCC12050

 

  1.   1
  2.   Overview
  3.   At a glance
  4.   What is EMI?
  5.   Conventional methods to reduce EMI in the low- and high-frequency ranges
  6.   Innovations in reducing low-frequency emissions
  7.   Spread spectrum
  8.   Active EMI filtering
  9.   Cancellation windings
  10.   Innovations in reducing high-frequency emissions
  11.   HotRod™ package
  12.   Enhanced HotRod QFN
  13.   Integrated input bypass capacitor
  14.   True slew-rate control
  15.   EMI modeling capabilities
  16.   Low-frequency EMI designs using WEBENCH® design tool
  17.   Conducted and radiated EMI results published in data sheets
  18.   Conclusion
  19.   Keep product categories for low EMI

Innovations in reducing low-frequency emissions

Look at a few techniques that TI uses when building its converters and controllers to address the fundamental trade-offs involving efficiency, EMI, size and cost.

GUID-20231208-SS0I-0FWT-BDL2-Q4S6VNCQQPJQ-low.gif Figure 7 EMI plots of square waveforms with different rise times.
GUID-20231208-SS0I-TBLC-HL55-91PJWDFWRJBW-low.gif Figure 8 The effect of different switch-node slew rates and associated ringing on high-frequency emissions. Reduced slew rates impact EMI roll-off in the 30- to 200-MHz band while the reduced ringing impacts EMI at the ringing frequency around 400 MHz.