Patent ID: 8146049
Filing Date: 2012-03-27
Classification: G06F

Abstract:
1. A design support apparatus configured to support design of a printed circuit board on which a device and a switching power supply, which supplies power to the device, are mounted, comprising: a calculation module configured to calculate, based on design information of the printed circuit board including capacitor information indicative of characteristics of at least one decoupling capacitor, a first impedance between a power plane and a ground plane in the printed circuit board at an ON time of a high-side transistor in the switching power supply, and a second impedance between the power plane and the ground plane at an ON time of a low-side transistor in the switching power supply; a determination module configured to determine one of the first impedance, the second impedance and a third impedance in an intermediate range between the first impedance and the second impedance to be an impedance between the power plane and the ground plane, based on ON-time information indicative of a ratio of an ON period of the high-side transistor to a switching cycle of the switching power supply in an operation period of the device; and an evaluation module configured to evaluate the capacitor information by comparing the determined impedance and a target impedance.