PCB ground plane for multiple Vcc

Thread Starter

Soban

Joined Aug 8, 2020
1
Hi all,

this is my first post in this forum.

im designing a line follower robot (car) PCB, and in this PCB im using two buck converters, the first one is used to power the motor driver ic with 7v and the second buck is to power my sensors with 5v.

my question might sound as a stupid one but can i use a single and common ground plane for all the PCB.
the schematic for the robot is as shown below
Schematic_Line_Follower_2_2020-08-08_21-12-24.png
 

ronsimpson

Joined Oct 7, 2019
928
There are many ways to do this. Some people would use two grounds. I would use only one ground but watch where the current flows. Do not let motor ground current flow through the sensor's ground.

I would have 5V_gnd, A0..A6 and 5V_Vcc have a good clear path to the Arduino_Nano. Maybe all on the right side of the board.
I might have U1 motor driver on the left side.
And the Arduino in the middle.
This way if the left side has high current the right side will not see it.
Keep the motor wires (traces) away from the computer and all inputs.
I see the motor "buck power supply" at the bottom center to left side while the buck 5V is bottom center to right side.

You can mark blocks on paper and then draw current paths. Power connector to power supply to motor driver to motor, back to motor driver back to power supply back to power connector. Now keep the sensors out of that current path.
 
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