Signal ground and Power ground implementation
Natnael , 12-09-2015, 11:23 PM
Hi,
i am trying to design a power supply using PMIC's from Linear Technology,in the datasheet there is a distinction between signal and power grounds, it says make them separate and connect them at a single point only, i understand the need to separate them but my questions is, is it a good idea to assign one ground plane to signal ground another to power ground and use a via to connect the two? or is there another way to implement this concept?
Natnael,
i am trying to design a power supply using PMIC's from Linear Technology,in the datasheet there is a distinction between signal and power grounds, it says make them separate and connect them at a single point only, i understand the need to separate them but my questions is, is it a good idea to assign one ground plane to signal ground another to power ground and use a via to connect the two? or is there another way to implement this concept?
Natnael,
robertferanec , 12-10-2015, 05:45 AM
Hello @Natnael,
in power supplies I normally only use one ground (even if they speak about power ground and signal ground). However, I am careful about how I place components and how I route the signals - for example, I do not place sensitive components and tracks into High current area. The best is to find an evaluation board of that chip and check how the chip manufacturer designed the PCB. If they use two different grounds, you may want to do it the same way.
In case you decide to split GND, I would use two different netnames + a component to connect these two grounds together. You can use for example 0R (I have used this), a special VIA component (I have never used this) or Altium supports a special component called net-tie (I have never used it, but it looks like it could be what you are looking for): "a Net Tie component would be (however not limited to) connecting two polygons of differing ground nets together at a specific place (AGND and DGND for instance), " ... more ...
in power supplies I normally only use one ground (even if they speak about power ground and signal ground). However, I am careful about how I place components and how I route the signals - for example, I do not place sensitive components and tracks into High current area. The best is to find an evaluation board of that chip and check how the chip manufacturer designed the PCB. If they use two different grounds, you may want to do it the same way.
In case you decide to split GND, I would use two different netnames + a component to connect these two grounds together. You can use for example 0R (I have used this), a special VIA component (I have never used this) or Altium supports a special component called net-tie (I have never used it, but it looks like it could be what you are looking for): "a Net Tie component would be (however not limited to) connecting two polygons of differing ground nets together at a specific place (AGND and DGND for instance), " ... more ...
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