Tokyo Shibaura Denki Kabushiki Kaisha

Hideaki Ito

Yoshio Wada

Hiroshi Sadamatsu

A switch circuit is comprised of first and second NPN transistors, the collectors of which are interconnected and the emitters of which are respectively connected to an input terminal and a reference voltage, third and fourth PNP transistors connected between the bases of said first and second transistors and a power source voltage, and fifth and sixth NPN transistors connected between the bases of the third and fourth transistors and ground. Seventh and eighth PNP transistors, connected between the power source and ground, are further provided, with their ON and OFF states being controlled by a control signal applied to the bases thereof. The bases of the fifth and sixth transistors are respectively connected to the collectors of the seventh and eighth transistors. The fifth and sixth transistors are ON/OFF controlled by the collector currents of the seventh and eighth transistors, respectively.

Transistor switch and driver circuit

A switching circuit for AC bias signal has an input terminal for inputting an input signal into the switching circuit and a first transistor connected to the emitter of the input terminal. A second transistor is connected at the collector to the collector of the first transistor. The emitter area of the second transistor is larger than that of the first transistor so that the dynamic resistances of the these transistors are equal to each other when these resistors are ON state. The emitter of the second transistor is connected to the reference voltage terminal supplied with ground voltage. The first and second transistors are controlled in conduction by a control signal as input.

Growing community of inventors

Kawasaki, Japan

Hideaki Ito