TIDT232 September   2021

 

  1. 1Description
  2. 2Device Description
  3. 3Efficiency
  4. 4Start-up
  5. 5Shutdown
  6. 6Output Voltage Ripple
  7. 7EMI Results
  8. 8Test Setup
    1. 8.1 EMI Scans - Single UCC12050, 5 VOUT, 100 mA
    2. 8.2 EMI Scans - 4x UCC12050, 5 VOUT
    3. 8.3 EMI Scans - Conclusion

6 Output Voltage Ripple

Output ripple voltage shown in the following figures is for a single output (ISO OUTPUT 1), VINP = 5 V, VISO = 5 V, POUT = 500 mW. The 25-kHz, low-frequency modulation in Figure 6-1 is a result of the UCC12050 spread spectrum modulation (SSM) used to reduce the EMI peak harmonic content.

GUID-20210409-CA0I-TQBL-QMWM-WQJSMCJ6FL9R-low.pngFigure 6-1 VISO1 (5 V) Modulated AC Ripple Voltage About 60 mV, 25 kHz
GUID-20210409-CA0I-D42R-0HWD-KXRWVG72PCFS-low.pngFigure 6-2 VISO1 (5 V) High Frequency, AC Ripple Voltage About 35 mV, 16 MHz