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I had to make my own DC-DC converter on the TPS54360 driver. But because of the driver for two cameras are very strong interference. I want to try to isolate the driver GND and design it with a track back to the ground, because I understand that my main mistake is a common Polygon of GND.

Scheme of TPS54360: enter image description here

My PCBs: enter image description here +12 - Power of cams +24 - Power of TPS54360

TOP: enter image description here

BOT: enter image description here

My result :'( : enter image description here enter image description here (the TPS54360 is on when the light is on) What else can you pay special attention to?

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  • \$\begingroup\$ comparing the size of your diode to that of your inductor: Are you sure that the inductor is rated for the average and ripple/peak current you're asking from it? My guess is that you're really not seeing noise in the classical sense, but simply a supply voltage with dropouts... \$\endgroup\$ Apr 27, 2019 at 22:31
  • \$\begingroup\$ in any case, adding more capacity in parallel to C27 and C28 would be the first thing I'd do. \$\endgroup\$ Apr 27, 2019 at 22:33
  • \$\begingroup\$ How many layers is your PCB? looks like just two... \$\endgroup\$ Apr 28, 2019 at 2:25
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    \$\begingroup\$ It’s possible that the switching noise is coupling upstream to the 24V supply and then back to the cameras’ 12V. Try adding a series choke at the 24V input right before the input capacitors C29 and C30. A ferrite bead is a good option. You can also try increasing C29’s capacitance. \$\endgroup\$
    – joribama
    Apr 28, 2019 at 15:02
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    \$\begingroup\$ The switching noise is likely coming from common ground that is shared between switcher and analog signals. This PCB layout is not salvageable. The switcher needs to be isolated as much as possible, and connected to signal ground at a single (power entry) point, such that all high-current spike loops have local return ground. \$\endgroup\$ Apr 28, 2019 at 17:16

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You have beat notes between the video sampling frequency and the switch reg ripple.

Add more LC filter sections.

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