SEMICONDUCTOR SWITCH CIRCUIT

PURPOSE:To reduce the gate current for the transition from the closed state to the opened state, by providing a transistor TR in parallel with a four-layered element where the gate can be turned on and off and connecting the base of this TR to a channel having the same conduction type of the intermediate layer of the four-layered element. CONSTITUTION:First, when a TR16 is turned off, TRs 15 and 17 are turned off. When a current is flowed to the base of the TR16 through a P gate terminal 13 and TRs 15 and 17 are turned on to set the closed state, the closing current is minute because of the positive feedback operation of TRs 15 and 16. When the closed state is set once, the closed state is held by the positive feedback operation of TRs 15 and 16. The current is led out to the external from the P gate 13 to turn off the TR16, and TRs 15 and 17 are turned off, thus switching the state to the opened state.