Tips for Power Supply Noise Reduction

Tips for Power Supply Noise Reduction

1. Design a stack up that keeps power and ground planes together.
2. Keep the separation between power and ground plane as small as possible.
3. Design a stack up that uses more power and ground planes.
4. Use bigger vias to connect decoupling capacitors to power and ground layers. Your system should have at least two types of vias, smaller vias for high speed signals and larger vias for power and ground connections.
5. Use wider traces to connect decoupling capacitors to power and ground planes.
6. Keep vias connecting power and ground ends of a decoupling capacitor as close as possible.
7. For larger capacitors use multiple vias to connect power and ground signals.
8. Use ceramic decoupling capacitor that has wider metal contact to lower the ESL (Effective Series Inductance). For example, a 0612 Capacitor will have lower ESL than 1206 even with same physical size.
9. Place decoupling capacitors as close to the IC power pins as possible.
10. If you are using multiple vias to connect a large capacitor to a power plane, keep them apart. Similarly, keep the multiple vias connecting the ground end of a large capacitor far.
11. Prefer a package with short leads. In DDR, for example if a choice is available, use BGA package over SSOP package.
12. Use large number of decoupling capacitor to reduce total effective series inductance.
13. Use smaller size decoupling capacitor. Prefer 0402 over 0603 or 0805.
14. Place power supply regulator IC close to the place where it will be used to minimize trace inductance.


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