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Please help with providing the guidelines for layout design for a double pulse test PCB. Following is the description:

  1. 4-layer board - Signal-Gnd-Power-Signal
  2. 2 Grounds - high voltage ground and microcontroller (for double pulse) ground.
  3. Application - operating at 100VDC and 30A drain current.

I need gate driver layout guidelines and placement guidelines of SMD inductor and DC-link capacitorss and the switching MOSFETS, as well as guidelines on traces.

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This is what comes to my mind... incomplete, but i hope it helps.

(1)

Do a "SIGNAL(1) - GND(2) - GND(3) - SIGNAL(4)" stack. Route Power on (1) and place only power-components/caps/inductors/drivers/connectors on (1). Place the MCU and its support (LDO, XTAL, whatever) on (4).

(2)

Do not split grounds. No benefit - only problems.

(3)

Do not route on (2) - if necessary, route on (3) but try to avoid it.

(4)

Spend 95% of your time on component placement - especially the power components.

Keep traces short and think about the current loop area.

(5)

If you connect GND-Pads on (1) to (2), use multiple vias and keep inductance in mind (DC-Resistance is an issue, but less important than via inductance).

(6)

Make sure to design the traces wide enough (use e.g Saturn PCB calculator). Think about adding PCB-solderable busbars (available via digikey etc...).

(7)

When you finished your layout, stitch the GND planes together with GND-vias. Be generous!

(8)

Think about test-pads/connectors: What measurements do you want to take? What test-points are required?

Is there a critical measurement? Maybe connect the signal via a BNC/SMA directly to your scope instead of using a probe?

(9)

Add some plastic stand-offs in the corner, so you can place the PCB on your desk nicely.

(10)

Think about safety: Yes, even in a lab. 100VDC is not a joke anymore, so maybe add standoffs on the top as well and place a plexiglass sheet above your PCB... Nice touch.

(11)

Think about the Silk-screen: Scratching your ehad in the lab before searching for the schematic PDF again takes time..... Use the silkscreen to your benefit.

(12)

Think about your connectors: How to connect your lab-supply/lab-sink/dut/pc nicely? 5mm banana? BNC? USB-A?

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  • \$\begingroup\$ Thanks for your comment. Regarding the 2nd point, grounds are isolated in my application. HV ground and LV ground. \$\endgroup\$
    – Andr7
    Jan 5 at 9:08
  • \$\begingroup\$ @Andr7 Is this because you "want" or you need galvanic isolation? If you need it, make sure to bridgegrounds with 1pF/1Meg in parallel if you feed digital signals from the MCU to the Driver side. \$\endgroup\$ Jan 5 at 9:12
  • \$\begingroup\$ I need it. I am using an isolated gate driver. \$\endgroup\$
    – Andr7
    Jan 5 at 9:16
  • \$\begingroup\$ @Andr7 Okay, understood. \$\endgroup\$ Jan 5 at 9:18

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