The PCB layout design is important for the performance of a linear voltage regulator. A good PCB layout can optimize the performance, whereas a poor one may impact on the stable operation of the regulator and introduce various disturbances in the system.
Here are some general recommendations for the PCB design with a linear voltage regulator:
- Place the output capacitor as close as possible to the regulator’s output and GND pins and on the same side of the PCB as the regulator.
- Place the ceramic input capacitor (e.g. 100nF) as close as possible to the regulator’s input pin and on the same side of the PCB as the regulator.
- Place the larger input buffer capacitor (e.g. 10µF) on the same PCB.
- Traces connected to the regulator’s input and output should be sized according to the current flowing through it.
- Ensure a good GND connection.
- For 4 or more layer PCBs, use one middle layer for GND and place sufficient number of vias to GND layer.
- For a 1 or 2 layer PCB, place a sufficient GND plane.
The PCB layout design is also crucial to the thermal performance. Here are some recommendations for a good thermal design:
- Ensure good thermal connection.
- Place sufficient cooling area depending on the power dissipation.
- For 4 or more layer PCBs, place sufficient number of thermal vias to the thermal layer.
- Put other heat sources on the board as far away as possible from the position of the linear voltage regulator.
Below is an example of a good PCB layout design:
PCB layout example