Spread spectrum technique offers a simple and cost effective solution for the average EMI noise reduction. Figure 3-2 through Figure 3-5 show the conducted and radiated EMI results (CISPR 11) for TPSM5601R5H and TPSM5601R5HS for a 24-V input, 5-V output, and 1.5-A Load. Emission tests were performed on the default evaluation board for both devices. As expected, the EMI results show that implementing the spread-spectrum technique reduced peak emissions while efficiency and output ripple did not have an impact. Note, both TPSM5601R5H and TPSM5601R5HS are compliant with EN55011 Class-B radiated emissions.

Figure 3-2 Conducted Emissions

Figure 3-4 Radiated Emissions

Figure 3-6 Output Ripple

Figure 3-8 Efficiency

Figure 3-3 Conducted Emissions with Spread Spectrum

Figure 3-5 Radiated Emissions with Spread Spectrum

Figure 3-7 Output Ripple with Spread Spectrum