LYT5216D-TL shorting (damage) issue 24V 150mA design

Posted by: Hitesh Gambhava on 08/19/2023

Hi,

I have used LYT5216D-TL for 24V, 150mA LED driver non-isolated design. I got reference schematic for this requirement from PI's support team and built a proto types around this.

During testing I am facing issue like LED driver board blown out randomly and in all cases we can see that LYT's Source and Drain get shorts along with current sense resistors. I can regenerate issue if I do board power on/off from mains 3-4 times within a 4-5 second.

Attached is the screen shot of schematic. Any insight is highly appreciated in timely manner.

I am struggling more than a month but no luck to find root cause.

Thanks,

Hitesh

Files

Attachment	Size
LED driver design.png	317.92 KB

Comments

Hi Hitesh,

What topology are you currently using? Looking at your schematic, I assume this is buck-boost? (Please correct my if I am wrong)

Please send your transformer construction and your PCB layout.

Thank you.

Regards,

Tarmo

Hi Tarmo,

I am using buck topology. Following is our construction windings. Is there any private channel where I can share the layout file?

Thanks,

Hitesh

Attach is inductor construction winding.

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Construction winding.png	19.6 KB

Hi Hitesh,

What's the operating input voltage range? Do you have any waveforms on the LYT5 Drain Source during start-up, normal operation, and fault? You can send your layout to my e-mail

Regards,

Tarmo

Hi Tarmo,

I have shared layout to your email ID. Our operating input voltage range is 95VAC-230VAC.

See attached LYT5 drain source start-up voltage.

Thanks,

Hitesh

Attachment	Size
waveform.png	886.54 KB

Hi Tarmo,

Any update on this?

Thanks,

Hitesh