Hi ,
I am troubled with the TIDA-00961 project( 1.6-kW High-Density GaN-Based 1-MHz CrM Totem-Pole PFC Converter).
I'm wondering how high frequency switches work in every high frequency cycle. Could you plz help me?
To be specifically, like in the picture below:(assume that in positive cycle, the yellow part is the lower switch and it is on during the Ton ,while the blue part is the high switch and it works on when the Toff)
My question is
Q1: How to arrange the time of the DeadTime2 (between the yellow part and blue part, the color is grey in the picture)? As we know, the time of DeadTime2 changes in every different input voltage. The bigger the input voltage, the shorter the time. Shall we fix this time？100ns? Maybe there will be a massive loss!! Considering GaN has a forward voltage when the current goes from drain to source.
Q2: How to decide the time of the Toff？in other words, when shall we switch off the sync. freewheeling switch? I noticed that we didn't detect the current in every channel(this is 2-phased interleaved).I see in somewhere we calculated the time of Toff？ Does it work over 1 MHz?
One more question, how to decide the time of Ton? the specific time of lower switch on?Just waiting for the auxiliary winding‘s voltage change? if so, the time of the DeadTime1 can't be a very time- it changes in every different input voltage.
Thanks for you attention. I have seen some answers of Mr. Hrishikesh Nene. Hopes my questions can be handled.
Best Regards,
Ginger
