Contents
Why are power planes split into multiple domains?
Having a single well of power for all the components on a signal layer to draw from makes a lot of sense if they all have the same voltage requirements. Increasingly, however, more complex high density PCB designs have made the practice of splitting a power plane into multiple domains more popular.
When do you need to split a power plane?
Increasingly, however, more complex high density PCB designs have made the practice of splitting a power plane into multiple domains more popular. If your MCU requires one voltage while your I/O ports need another, you may need to split the reference plane to accommodate both voltages.
What happens when traces cross a split plane?
On a 4-layer board this means the power layer, more often than not, will be split up, and, as a result, traces crossing splits or slots on adjacent reference planes are often unavoidable. Let’s assume we have a pair of traces on the top layer crossing a 50 mil gap on the adjacent layer as shown in Figure 2.
How many layers should a power plane be?
You’ll notice that you will generally only see power planes in boards with 4 or more layers. This is because the best practice for multi-layer stackups are to use an even number of layers.
How is a power plane connected to a ground plane?
Similar to how the ground plane is connected to the ground connection of the power supply. Its purpose is to provide a steady supply of voltage to your board. Whenever a component needs to draw power, simply run a trace to a via that makes contact with the power plane and completes your circuit.
Why do I need a power plane board?
In order to light a lightbulb, spin a motor, or otherwise perform some action such as maintaining the optimum temperature on your DIY espresso machine, your board needs a steady supply of voltage to function.
How is a power plane connected to a PCB?
What is a Power Plane? Often designated as a VCC in PCB design, a power plane is simply a flat plane of copper connected to a power supply. Similar to how the ground plane is connected to the ground connection of the power supply. Its purpose is to provide a steady supply of voltage to your board.