I have been evaluating Full bridge phase shift control using UCC28951 controller. I have few questions regarding this.
1) I see that the current sense feddback is recommended to be put on dc link return path to capture the link current.
I have a question, if I put it on switching node or in series with transformer primary current, what are the downsides to it? With CT in series with transformer primary, It is obvious the CT will be automatically reset every cycle, since it will be carrying HF ac current and switching commutation loop for the phase-legs can now be very optimized. Has someone considered this before or can share any downside in putting the CT in series with transformer?
2) I have been trying emulate the block diagram model for UCC28951, but needs some more information than it is available. What is the stepdown factor for error amplifier output signal going into PWM comparator ? Similarly, is there any scale-down factor for the Ramp signal going into PWM comparator?
Thanks
Ritwik
