Dear All,
Sorry for the late reply.
I am attaching waveforms of the IC28950 pins such as CS,SS,COMP, EA- and also transformer primary. I am also attaching the schematic used.
The final requirement is 1.5kW at 48V. However for initial testing, I have changed the sense resitor to get a voltage of 24 V in output(Input is varied from 0 to 150V). I am attaching waveforms captured in attached pdf. The load resistance presently used is 4 Ohms. The transformer primary inductance is 2.6mH and leakage inductance is 7uH. I am not using any shim inductance.
The key observation is that the transformer voltage is nearly square wave. Once system reaches 24V, any further increase in input voltage the system goes to burst mode.
Also it is observed that the Gate Voltage of QA starts dipping and then nearly turns of as the system output voltage reaches 24V. I am also attaching updated daughter board schematic values.
How should I troubleshoot the issue.