This paper presents a new decoupling circuit for multi-power-terminal VLSIs to suppress strong radiated emissions caused by power plane resonance of multilayer printed circuit boards (PCBs). This circuit is based on a previous /spl pi/-network filter consisting of two capacitors and one power trace. The power trace, designed in agreement with transmission line theory, was used in place of the ferrite bead inductor of a conventional /spl pi/-network filter. The new circuit has been so designed that when a number of them are applied in combination to a multi-power-terminal VLSI, they can share capacitors, thus reducing the total number of capacitors required. Both calculated and measured high-frequency characteristics of power buses in PCBs show that in wide-band frequencies this new circuit isolates a VLSI, the source of switching noise, from power distribution buses, which would otherwise resonate that switching noise. Measurements of emissions from PCBs mounted with a 208-pin VLSI demonstrate that this circuit reduces emission levels more effectively than does conventional capacitor-only decoupling circuit.
[1]
H. Arakaki,et al.
Three-dimensional noise current distribution on power and ground planes in printed circuit boards
,
1998,
1998 IEEE EMC Symposium. International Symposium on Electromagnetic Compatibility. Symposium Record (Cat. No.98CH36253).
[2]
B. Archambeault,et al.
Modeling the effectiveness of decoupling capacitors for multilayer PCBs
,
1998,
1998 IEEE EMC Symposium. International Symposium on Electromagnetic Compatibility. Symposium Record (Cat. No.98CH36253).
[3]
S. Caniggia,et al.
Investigation of EMI on multilayer printed circuit boards: radiated emissions
,
1996,
Proceedings of Symposium on Electromagnetic Compatibility.
[4]
H. Sasaki,et al.
A new decoupling technique for suppressing radiated emissions arising from power bus resonance of multilayer PCBs
,
1999,
1999 International Symposium on Electromagnetic Compatibility (IEEE Cat. No.99EX147).