Other Parts Discussed in Thread: DRV8301, TPS54160, TPS768, TPS746, TPS746-Q1
Hello TI, I wish you a happy new year!
I have a motor controller board that has a few issues with quite a noise (80-100kHz) on the 3.3V rail. It’s the board of a friend and I think the noise comes from messing up the ground.
The TPS54160 Buck Converter (DRV8301 Buck Converter) is used to generate 5V and a the TPS76833 is used to generate 3.3V from the 5V line.
He asked me to help him on the circuit and layout and we have created this:
In the picture you can see the new board. Now there is only one ground connection point at the bottom of the DRV8301, next to that is the VDD connection point (purple lines). Both with star connection from the input connector. I think that should be right?
I placed the TPS76833 a bit away from the Gate Driver and Buck Converter.
In the picture below there is the DRV8301(Buck Converter) schematic.
I added a filter before the PVDD Buck input (yellow line) and on the output of the Buck Converter a ferrite bead (purple line). What do you think about that?
I’m also thinking about adding a ferrite bead on the input of the Gate Driver (blue line).
On the input of the 3.3V Regulator I added an RC-Filter with a resistor value of about 1-3 ohm, would that make sense?