First off, I'm new to pcb design and I'm trying to learn a bit for some simple projects. This project was a bit out of my realm, so I hired someone through another forum to help me out. When I reached out stating it didn't work, I haven't heard back.

I'm trying to understand why this isn't working. I actually paid someone to design this for me, they have since ghosted me. I've ordered the PCB's assembled, and upon testing with my bench supply I'm having a few issues. If I apply 12v to either VIN, the display on the bench supply drops the voltage to 5v, and the FET heats up quickly. All the outputs, including the unregulated output, only read about 4v and that drops as the FET continues to heat up.

When reviewing the TI docs, it seems HB and HS should be connected with a polarized cap, my design does not have that. I can make the change, but I'm unsure of which size cap to use. I also would appreciate if anyone had a moment to review the schematic to see if anythign else stands out.

Thank you for your time.

 

Hi james,
I have not used that device, but there is a Calculator available, Search the calculator for Chb value.

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