PCB Power Supply Design Important Concerns

Whether your next device runs on battery power, a solar element, or plugs into the wall, you’ll need to design circuitry to regulate the power leading to your device. PCB power supply design can encompass more than just an actual power supply; systems ranging from personal computers to home appliances need a power supply to convert AC power from the wall to DC power with low noise content.

PCB power supply design is about more than just converting between AC and DC power. There are power and signal integrity issues to consider, as well as thermal management issues that arise with high power electronics. In fact, signal and power integrity are intimately related due to the way ICs operate, and some power supplies can produce significant radiated EMI that affects other parts of a circuit board.

No power supply or the system connected to it is immune from signal integrity or power integrity problems, but implementing some simple design procedures can help prevent a redesign. These best practices include everything from proper component arrangement to decoupling/bypassing, and stack up design.

For the power supply design, the designer needs to execute a good PCB layout and plan an efficient power distribution network. Also, the designer needs to ensure that noisy digital circuit power supplies are separated from critical analog circuit power supplies and circuits. Some of the important things to be considered are discussed below:

1. Choosing the right regulator for PCB power supply
2. Thermal management for power supply
3. Ground and power planes for better PCB power supply
4. Decoupling capacitor and bypass capacitor
5. EMI filtering
6. Frequency response for power delivery system
7. Power integrity (PI)

Conclusion

Good power supplies are the key to the accurate functioning of an electronic device. As we have seen, the PCB designer has several options available when considering the design of a power supply. The choice of regulators, capacitors, and EMI filtering is important in those considerations. Similarly, the thermal effect and load response should also be considered while designing a power supply system.

At the same time, follow the recommendations mentioned in the power supply IC data sheets. The trace thickness and component placement play a critical role in the power supply design.