Hitachi, Ltd.

Hitachi Computer Engineering Co., Ltd.

Katuhiro Morisuye

Makoto Hayashi

Katsuyoshi Washio

Tomoyuki Watanabe

Takahiro Okabe

Makoto Furihata

Shizuo Kondo

Setsuo Ogura

A logic circuit is provided which includes a first multi-emitter transistor with its emitters coupled to a group of first input lines and a first transistor with its base coupled to the collector of said first multi-emitter transistor. A second transistor is also provided with its base coupled to the collector of said first transistor, said second transistor having a polarity opposite to that of said first multi-emitter transistor. A second multi-emitter transistor is connected with its base coupled to the collector of said second transistor and with its emitters coupled to a group of second input lines, and a third transistor is connected with its base coupled to the collector of said second multi-emitter transistor and with its collector coupled to an output line. The collector of said first multi-emitter transistor is coupled to the emitter of said second multi-emitter transistor in order to absorb minority carriers stored in the transistors. This feature significantly improves the circuit operating speed. A further feature is the provision of a logic circuit which is highly integrated and which consumes reduced amounts of electric power, while maintaining high-speed performance of the TTL circuit, by substituting a multi-collector transistor that reversely operates for an inverter portion of the TTL circuit.

Bipolar logic circuit having two multi-emitter transistors with an

Growing community of inventors

Kodaira, Japan

Katuhiro Morisuye