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BOOSTXL-DRV8301 to Custom Hardware

Other Parts Discussed in Thread: BOOSTXL-DRV8301, DRV8301-69M-KIT, OPA374


I have a question about the BOOSTXL-DRV8301 as reference to build my own hardware.

What is the best position for the 1000pF capacitor over the differential measurement signal from the shunt. I see on the BOOSTXL-DRV8301 (C31,C32 and C33) layout that they are placed as close as possible to the shunt. On the other hand on the DRV8301-69M-KIT they (C75,C78 and C84) are placed as close as possible to the Op Amp and resistors.

And second question:

The 1.65V reference voltage for the third shunt measurement Op Amp is generated by an OPA374 Op Amp in voltage follower mode. Is it correct to place a 2.2uF (C38) capacitor on the output of this Op Amp, because in the datasheet I read that it can drive only 250pF in unity gain.


  • Hi Rixo,

    Space allowing, I would recommend placing them as close to the differential amplifiers inputs as you can. This would be to eliminate as much high frequency noise from entering the amplifier. This is on the rev list for BOOSTXL-DRV8301 but may not be feasible as space is tight. 

    I am not as sure on your second question. I agree that this capacitor seems over sized. The Op Amp is OPA2374, but I think this is still a concern. I am investigating furthur.

  • Hi Nick

    Thank you very much for your answer. Is this rev list for BOOSTXL-DRV8301 PCB somewhere available?

    About my second question: It seems logical to place a cap to buffer this reference voltage but it sounds illogical from the Op Amp side. Maybe I can ask this question better in the Op Amp forum?

  • Hi Rixo,

    No, this is not a public document. Just a list of minor tweaks we would make if we decide to rev the board (nothing that would impact functionality).

    I am still investigating internally, I have not received an answer yet. You are welcome to ask on the Op Amp forums about their thoughts on capacitive loads on unity gain buffers.