LM5036: How to Realize the Minimum Dead time？

shaowei cui

Part Number: LM5036

Hi TI Engineers,

According to section 7.3.7 of LM5036, minimum dead time can be obtained between SR1 and LSG, but how can it be achieved?

regard,

shaowei

over 6 years ago

0 Sonal Singh over 6 years ago

TI__Expert 6080 points

Hello Shaowei,

Thank you for your interest in LM5036.
You can set the deadtime t1 to its minimum value by setting RD1 to zero, this will set t1= 85ns.

Regards,
Sonal

Please hit "Answered" if your query is resolved.

0 shaowei cui over 6 years ago in reply to Sonal Singh

Intellectual 590 points

Hi Sonal,

When I changed the resistance to zero, the power supply stopped working.Why?

Regards,

shaowei

0 Sonal Singh over 6 years ago in reply to shaowei cui

TI__Expert 6080 points

Hi Shaowei,

I think changing the RD1 to zero did set the delay to it's minimum but doing that might have introduced an overshoot in the output and you might have ended up damaging your SR or other components.
Can you please explain stop working? and identify broken components?

Regards,
Sonal

0 shaowei cui over 6 years ago in reply to Sonal Singh

Intellectual 590 points

Hi Sonal,

It's not working at all after the power is turned on.

Regars

shaowei

0 Sonal Singh over 6 years ago in reply to shaowei cui

TI__Expert 6080 points

Hello Shaowei,

I was able to reproduce this error in LM5036, thank you very much for pointing it out and we are working on identifying the bug.

When the RD1 is set to zero there are packets of switching period when the turn-ON of the LSG and SR1 is overlapping which causes the damage on the sec side. Please use the recommended dead time(RD1=1kOhm) for now and I will keep you posted for any updates on this issue. Please refer to figure 7 on page 10 of the LM5036 datasheet for reference.

Regards,

Sonal

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LM5036: How to Realize the Minimum Dead time？