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Some schematic questions
#2
Another question:
  • How is the value for C5/C6 in the H-bridge calculated?  And what characteristics should D1/D2 have?
Here's the datasheet for the NCP5106B MOSFET gate driver:

  https://pdf1.alldatasheet.com/datasheet-...5106B.html

It doesn't show how C5/C6 should be calculated.  Figure 53 in the datasheet shows an extra diode to protect against negative voltages, and the diodes are MUR160, same as in the schematic.  Figure 53 also shows a direct connection between the gate driver output pins and the MOSFET gates (whereas the schematic has 47R current limiters).  Figure 53 also has a 100n bootstrap capacitor, whereas the one in the schematic is 1u (a mistake?)

Regarding the value for C5/C6, I found this app note for a SiLabs gate driver:

  https://www.silabs.com/documents/public/.../AN486.pdf

It shows how to calculate the value for the bootstrap capacitor.  But an important part of the calculation is to know the gate capacitance for the MOSFET.  The schematic doesn't say which MOSFET.

I wasn't able to find NCP5106B gate drivers., so I have bought some DGD1503s.  I've compared the two datasheets and the NCP5106B seems a bit faster, but I think the DGD1503 should also work.  I just want to make a circuit to test the pypilot version of motor.ino and @McNugget's version.

Thanks for any pointers.
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Messages In This Thread
Some schematic questions - by CapnKernel - 2020-01-20, 02:01 PM
RE: Some schematic questions - by CapnKernel - 2020-01-21, 03:07 PM
RE: Some schematic questions - by seandepagnier - 2020-01-21, 05:06 PM
RE: Some schematic questions - by CapnKernel - 2020-10-06, 06:06 AM
RE: Some schematic questions - by wdee - 2020-01-21, 06:00 PM
RE: Some schematic questions - by seandepagnier - 2020-01-21, 07:21 PM
RE: Some schematic questions - by seandepagnier - 2020-10-06, 07:04 AM
RE: Some schematic questions - by CapnKernel - 2020-10-06, 07:07 AM
RE: Some schematic questions - by kaa39518 - 2020-12-03, 07:36 AM
RE: Some schematic questions - by rastam4n - 2020-10-15, 03:34 PM
RE: Some schematic questions - by seandepagnier - 2020-10-15, 07:10 PM
RE: Some schematic questions - by rastam4n - 2020-11-10, 06:14 PM
RE: Some schematic questions - by xfactor99 - 2020-11-10, 06:48 PM
RE: Some schematic questions - by seandepagnier - 2020-11-11, 08:35 PM
RE: Some schematic questions - by rastam4n - 2020-11-11, 11:31 PM
RE: Some schematic questions - by seandepagnier - 2020-11-13, 05:29 PM

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