Ben Abel’s Work Log

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  • Post last modified:October 7, 2023
  • Reading time:3 mins read
  • Post category:Work Logs

9/17/23 – 9/23/23

Researched converter configuration options for isolated DC to DC converter, either a Flyback or Buck

  • Flyback is typically seen in lower powered applications [100 watts]
  • Flyback does have built in galvanic isolation
  • Buck could provide better efficiency but at the cost of a larger foot print

After meeting with our sponsor’s engineering advise we decided to go with a flyback design

Began focusing on the AC side to DC side before the flyback stepdown converter

  • Looking into creating an accurate model of a typical AC wall input for Simulations
  • Sizing components for the Passive Power Correction
  • Mitigating EMI

9/24/23 – 9/30/23

Began researching Power Factor Corrections options

  • Deciding Between Active or Passive PFC – Active choose because it allowed for better power factor as well as a wider range of input voltage

After deciding to go with an Active PFC, needed to decide what type of control mode to choose from:

  • Continues Current Mode [CCM]
  • Critical Conduction Code [CrCM]
  • Discontinues Current Mode [DCM]

After reviewing it was decided that a CrCM would be the best option because it has the lowest ripple current and it can be used in an interleaving mode which allows small component sizing, but at the cost of a high component count compared to the other modes.

Component sizing for 2 possible CrCM interleaving PFC ICs and identification of which IC would be better suited.

  • UCC28065
  • UCC28060