Patent ID: 7639061
Filing Date: 2009-12-29
Classification: H01L,H03K

Abstract:
1. A capacitance regulation circuit that regulates a capacitance which is added to a semiconductor element having a first main electrode, a second main electrode and a control electrode, a current flowing between the first and second main electrodes being controlled by a control signal which is input between the control electrode and the second main electrode, comprising: a capacitor; and a switch, wherein the switch operates so that the capacitor is connected between the second main electrode and the control electrode during a part of a period when a voltage between the second main electrode and the control electrode changes in accordance with a switching operation of the semiconductor element, and the capacitor is connected between the second main electrode and the control electrode in response to detection of a change in voltage between the second main electrode and the control electrode such that the capacitor is connected between the second main electrode and the control electrode only when the voltage between the second main electrode and the control electrode substantially changes.