TIDT232 September 2021
A comparison between a single, 5-V, 500-mW, UCC12050 (Figure 8-3, Figure 8-4) vs four, 5-V, 500-mW, UCC12050 converters (Figure 8-5, Figure 8-6) demonstrates almost no notable difference in radiated EMI, under identical operating conditions. Cable length, shielding and relative cable position is critical to radiated EMI CISPR 32 results. The UCC12050 includes SSM which greatly reduces sharp harmonic peaks, offering significant benefits for passing radiated EMI. Four UCC12050 converters have been shown to pass CISPR 32, class B without external ferrite beads (Figure 8-7, Figure 8-8). Ferrite beads placed at the input of each UCC12050 have been shown to significantly improve radiated EMI.