I watched TI's basic flyback video about the different control methods. and I am confused about some things, please see mine below questions.
1.) Valley Switching and QR, last time I ask a question about Flyback Frequency Foldback Mode (FFM) and Skip Mode and the answer is when the load current is decreasing, the switching will be reduced to improve the efficiency. but in TI's video (QR mode), "fsw decrease as load increase", so I am confused about that.
2.) Valley switching is equal to QR in the flyback?
3.) The reason we need more ringing in deadtime is for average output power? I don't very understand why increased deadtime and having more ringing will achieve the average power.