I have several questions about the current sensing through a resistance.
The resistances are 2-SMD package and I will use the 4-wire kelvin method for the layout.(see image) Specifically, there are three resistors, one of 1 mOhm and another two of 10 mOhm.the layout would be approximately like this:
The PCB is two layers with components only in the top layer and the ground plane in the bottom layer.
Due to restrictions in the layout, I can not find a way to route the sense tracks through the upper layer since they cut different power planes, so I will have to use vias and to route the sense tracks in the bottom layer.
Due to my limited knowledge of electronics, I am presented with the following questions:
- Each sense track will route using two vias (top to bottom layer and then bottom to top layer). As long as the resistance of each sense tracks are the same, should the use of vias not affect the accuracy of the measurement, right?
- Route the sense tracks in the bottom layer (where is located the ground plane), would it affect the accuracy of the measurement?
- Should I increase the trace width to minimize the effects of the EMI?
Thanks!