Patent ID: 7391269
Filing Date: 2008-06-24
Classification: H03F

Abstract:
1. An amplifying circuit formed on a semiconductor substrate and comprising: a depression type MOS transistor in which a grounding voltage is given to the gate of the depression type MOS transistor through a resistor together with an input signal; a MOS transistor in which the source of this MOS transistor is connected to the drain of said depression type MOS transistor, and an electric power source voltage is given to the gate of this MOS transistor, and the drain of this MOS transistor is connected to an output node, and the electric power source voltage is applied to the drain of this MOS transistor through a load impedance; and a logical gate for giving a voltage according to the electric power source voltage or the grounding voltage to the source of said depression type MOS transistor in accordance with a control signal for controlling an amplifying operation.