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Hello all! I am new to Altium PCB Design. Can anyone give a review on the schematic before I move on to the layout? Should I include more net classes? If yes, where and why?

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  • \$\begingroup\$ Out of curiosity, why are you using a two-output gate driver for a single output? \$\endgroup\$
    – Hearth
    Oct 19, 2023 at 15:25
  • \$\begingroup\$ R3, no HV supply capacitor, and a lack of indicated Kelvin source connections for Q2 may cause you to have a bad time. \$\endgroup\$
    – W5VO
    Oct 19, 2023 at 15:43
  • \$\begingroup\$ @Hearth to match the actual intended converter (gate loop parasitics) which uses dual output gate driver for driving mosfets \$\endgroup\$
    – Andr7
    Oct 25, 2023 at 4:50
  • \$\begingroup\$ @W5VO didn't get your lack of Kelvin source connection point, what does it mean? What will happen? \$\endgroup\$
    – Andr7
    Oct 30, 2023 at 9:06
  • \$\begingroup\$ You want to isolate the gate drive loop from the drain-source current loop to minimize the impact of switched current on your gate voltage. Imagine you have a few (5) nH of inductance If you have a sudden change in drain-source current. If the drain-source current was changing at say 1 A/ns, then it will develop 5V across the source lead, turning off your transistor. Your transistor will oscillate between on and off, with possibly explosive results. \$\endgroup\$
    – W5VO
    Oct 30, 2023 at 19:45

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In general, the schematic looks pretty good.

I always try to add detail to the circuit because in six months (or sometimes a day) I'll forget what it does. Here are some suggestions:

  • Add names to nets (under place/net_label). It makes it easier to find traces.
  • Add colors to nets to make it easier see what is connected to what (under view/set net colors). I typically do this to traces like GND which go to a bunch of things. Or when you have multiple grounds like you do.
  • Remove pin numbers for non-polarized parts such a resistors.
  • It appears that your capacitors have a reference designator that are only numbers? I'd add a C before the number.
  • For your input power connectors, add a text box (under place / text_frame) indicating the input voltage (nominal and maximum) and current. For output connectors I'll put the voltage range. Labeling connectors as an input or output isn't a bad thing.
  • If I'm handing the schematic off to someone else I sometimes put a note in the bottom left indicating what the circuit does.
  • Use net classes to group traces that are special in the layout. For example, is the trace a high voltage trace which requires additional spacing? Are the traces impedance controlled? Do the traces pass high current? If yes, then I assign a net class. I usually use a net class name like "50_Ohm", "1_A", "250_VDC", small enough to fit on the schematic, but easy to understand.
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