There is no info available on the topic. Where should components be paced on the pcb board? Here is the screen from the datasheet of DRV8305.

  1. Where should the 1uF capacitors on high side MOSFETs be placed?

  2. Where should 470uF capacitors be placed? 0.1uF and 0.01uF?

  3. 1000pF caps from SN to SP?

  4. SENSE devider resistors and the cap?

It is interesting to read about the logic of the placement also, why they should be placed there and not here.

Thank you!

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  • \$\begingroup\$ Typically the schematic gives a hint - as it does here. Caps are near whatever they are supposed to be placed close to. \$\endgroup\$
    – pipe
    Oct 2, 2016 at 22:19
  • \$\begingroup\$ Thanks. What about ASENSE, BSENSE, CSENSE deviders and caps? Components should be placed near the warming MOSFETs and the trace should go to MCU, or should they be placed near the MCU? \$\endgroup\$ Oct 2, 2016 at 22:29

1 Answer 1


Component placement is something that can require many days of thinking and planning, and you should really start by analyzing the current flow through the circuit, separating critical and non-critical sections, etc. I can not cover all of that, but I will try to answer some of your specifics.

As I mentioned in my comment, a good schematic will have hints on component placement, and this is not an exception. The 1 µF capacitors you ask about are all located near their respective MOSFET, and this reveals their purpose - they act as "energy reservoirs" for fast changes in current and should be placed close to the transistors.

SNx and SPx are across a 5 mΩ sense resistor and the capacitor is drawn right across it. As you can see, it would probably have been easier to draw the bottom leg of the capacitor to ground, but they refrained from doing so, likely because they want you to place it close. Here it's also important to note that even though SPx are actually connected to ground, they want you to make a trace directly to the resistor pads.

The 470 µF capacitors should not be as critical. These are bulk supply capacitors, and usually placed right next to where PVDD enters the board. They could also be placed near the power section, but those two should be the same - you should preferably have power entering the board where it's used.

Lastly, the A/B/C/PVDD SENSE dividers, they shouldn't be critical, as there won't be much current flowing through them. I would put them somewhere between the power section and the MCU on the board. They are connected to the ADC, and since I don't know the speeds involved, I can't give any better advice.


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