My customer have some questions regarding TPS7A78EVM waveform.
We change the AC input voltage from 80VAC to 240VAC and find the value of SC IN and AC+ voltage is constant.
however, the [H] duty of SCIN begins to decrease when we increase the AC input voltage as follows.
Regarding on the waveform as follows we have some question, please give us an explanation.
1. Why is the AC+ voltage constant ? even if we change the AC INPUT voltage. whether there is a clamp circuit ?
2. IS there a minimum on DUTY spec for SC IN PIN? if we increase AC INPUT voltage above 300VAC or higher,
the SCIN pin or AC+ PIN will be broken because of overcurrent ?