Abstract: A PCB (Printed Circuit Board) design support system and a PCB design method reduce radiation of electromagnetic waves by optimizing layout of a substrate while following a conventional method for designing a PCB and maintaining a conventional structure. The PCB design support system includes an input information section for a ground plane structure, power plane structure and layout of a PCB, a circuit model section for calculating voltages between the ground plane and power plane and distribution of currents flowing on the ground plane and power plane using input information, a frequency selection section and a section to display obtained voltage and current distribution in a form of two-dimensional voltage and current distribution maps corresponding to shapes of the PCB. The PCB design support system enables a via-hole disposed between planes and/or wiring installed between planes causing variations in voltages to be specified in a precautionary manner from a PCB design stage.

Abstract: Disclosed is a power decoupling circuit generating system and method capable of easily generating a power decoupling circuit for each device such as an LSI. On the basis of information regarding parameters of generating a power decoupling circuit held in a capacitor parts library and a line calculation parameter file, a power decoupling circuit of a &pgr;-type low pass filter construction having first and second decoupling capacitors to be added to a power supply terminal of a device as a target from which high frequency noise is prevented from being passed to a power plane and a power line corresponding to an inductance is automatically generated by a power decoupling circuit generating unit, thereby making calculation for generating the power decoupling circuit unnecessary.

Abstract: Disclosed is a power decoupling circuit generating system and method capable of easily generating a power decoupling circuit for each device such as an LSI. On the basis of information regarding parameters of generating a power decoupling circuit held in a capacitor parts library and a line calculation parameter file, a power decoupling circuit of a &pgr;-type low pass filter construction having first and second decoupling capacitors to be added to a power supply terminal of a device as a target from which high frequency noise is prevented from being passed to a power plane and a power line corresponding to an inductance is automatically generated by a power decoupling circuit generating unit, thereby making calculation for generating the power decoupling circuit unnecessary.