I am trying to adapt mi fly-back circuit (60W PWM fixed frequency) to the new UCC28700 fly-back controller.
At bench test I noted that the circuit accomplishes to the control law in first step (from 1 Khz to 40 Khz) Once reached that point the “Control Law Profile” said that frequency must to remain constant and turn into de AM control mode. Instead of that the frequency goes down and the circuit enters in current limit mode.
I tried several primary inductance and different primary peak current. I did not note difference.
I will appreciate any clue to helps my research.
