TNY276 CCM and DCM identification
Hello,
I am testing a multi-output flyback powersupply with TNY276GN chip. The input voltage range is 85V DC to 374V DC and the outputs are +5V @0.15A, -5V @ 0.15A, +15V @ 0.1A. The transformer magnetizing inductance is 686µH. Even though the design is for DCM, I get to see both CCM and DCM waveforms. I am not very familiar with operation of PI switchers and this is my first design with PI chip. Even the design guidelines in AN-23 is different from conventional design methodology. Please look at the attached waveform and comment on how to identify the mode of operation. For a given input voltage and load, how can one see both CCM and DCM operation?
Comments
No, I don't have a capture. It looks the same even with 10% load.
Hi,
How about some schematic capture or file? We would like to check if your schematic is correct with respect to the IC. Thank you very much.
Hi,
Thank you very much for considering Power Integrations product. Just a few questions, do you also have some waveforms for say 25%, 50%, and 75% loading condition? Just would like to check on this first to make sure you are operating properly.