problem in bringing up a 440w LLC

[mirbagheri1122]

Hi
I have builded a LLC buck regulator based on datasheet of LCS708 from pi.
and gave it 380 v directly but response that i get is 3v instead of 44v i attached my schematic and pcb
my ic draw 80 ma current.
please check sch and pcb
thanks for any guidance

[mirbagheri1122]

Hi
i changed ic and started to rise voltage with variac and no load.but in 30v (input) output starts to rise up slowly from 6v to 30 v that i turned it off but my hb voltage is rectangular.
Frequency is 170khz
Strange for me is secondary waveform that increases slowly and triple that compelled me to turn it off.
Output cap is electrolytic that I will change it.
Thanks alot

[ali_asadzadeh]

Hi,
Please upload your design file spread sheet

[mirbagheri1122]

Hi
this is my spreadsheet
and hb pin voltage
thanks

[ali_asadzadeh]

Please upload the PI expert Spread sheet

[mirbagheri1122]

Hi
i reached to regulated voltage at 40 % of nominal input voltage.and output is very good.
with load of 10w after 30 min my ic shut down happened.and after turning off input i saw my core is very very hot.
ofcourse i changed turns numbers to 12.5 and 2.5.i think i found problem of core overheating.maybe is because of my low secondary turns that is 2.5 and BAC is 525.but in new spreadsheet that nurn number is 25 and 5 because of my new constant Lres that is 70uH and is about high.i cant satisfy other conditions.
thanks alot.

[mirbagheri1122]

Hi
When i increase voltage more than 340v my device goes to off state and out put decreases to .4v[with 8w load].
my ov/uv pin is disabled.
Thanks