Switching circuit having a reduced output impedance

摘要

In a switching circuit for use in a mobile telephone device in controllably transmitting a speech signal to a radio transmission unit through an output terminal (312), a first switch (31) is controlled by a control signal which is supplied to a control terminal (32) with a high level and a low level of putting the first switch in a conductive and a non-conductive state when a second switch (36) is put in its off and on states. A capacitor (35) is connected between the control terminal and the output terminal in order to make the switching circuit have a low output impedance when the first switch is put in its off state.