Contents
How to decouple power from ground plane noise?
Effective Power/Ground Plane Decoupling for PCB Dr. Bruce Archambeault IBM Distinguished Engineer IEEE Fellow IBM Research Triangle Park, NC [email protected] IEEE October 2007 October 2007 Dr. Bruce Archambeault 2 “Ground Bounce” Power Plane Noise Control October 2007 Dr. Bruce Archambeault 3 Power/Ground-Reference Plane Noise
How to reduce noise in a PCB design?
Some PCB layout tips that can help reduce noise in your design. A look at some PCB design CAD tool features that can help. It is early morning and my backyard neighbor has decided to continue the construction project that he started yesterday.
How to decouple power and ground planes for PCB?
October 2007 Dr. Bruce Archambeault 16 Measured S21 for 12″ x 10″ PC Board Between Power/Ground Planes with Various Amounts of Decoupling Capacitors (Measured Center to Corner) -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 0.0E+00 2.0E+08 4.0E+08 6.0E+08 8.0E+08 1.0E+09 1.2E+09 1.4E+09 1.6E+09 1.8E+09
How are the signal layers of a PCB supposed to work?
Ideally, the signal layers of PCB will be sandwiched between power and ground planes allowing for a clear return path on the ground plane. If the plane is blocked by holes or split planes then the signal return will wander around trying to find its way back creating noisy interference as it goes.
How does power decoupling work on a PCB?
– Requires TRANSIENT analysis – Charge will NOT travel from far corners of the board fast enough – Local decoupling capacitors dominate – Impedance at ASIC/IC pins important October 2007 Dr. Bruce Archambeault 10
How big is a decoupling capacitor via separation?
Comparison of Decoupling Capacitor Via Separation Distance Effects 0.1 uF Capacitor 10 mils Via Separation October 2007 Dr. Bruce Archambeault 32
What’s the difference between a via and a plane decoupling?
Comparison of Decoupling Capacitor Impedance 100 mil Between Vias & 10 mil to Planes 0.01 0.1 1 10 100 1000 1.0E+06 1.0E+07 1.0E+08 1.0E+09 1.0E+10 Frequency (Hz) Impedance (ohms) 1000pF 0.01uF 0.1uF 1.0uF October 2007 Dr. Bruce Archambeault 31 Via Seperation (mils) Inductance (nH) Impedance @ 1 GHz (ohms)