Kabushiki Kaisha Toshiba

Takeshi Sugoh

Hiroyuki Hara

Yasuhiro Sugimoto

Hisashi Sugiyama

Yoshinori Nitta

A semicustom integrated circuit comprises pads arranged on peripheral portions of a chip along the four sides thereof. Peripheral circuit cells are arranged on a part of the chip to the inside of the pads. An internal circuit is arranged on a part of the chip to the inside of the peripheral circuit cell. The peripheral circuit cells include an ECL level input circuit an ECL level output circuit, a TTL level input circuit and a TTL level output circuit. Main source lines are formed on the peripheral circuit cells so as to surround the internal circuit. The main source lines are connected to pads to which source potentials is applied. Branch source lines cross the main source lines and connected to a selected one of the peripheral circuit cells and said internal circuit. The main source lines are selectively connected to the branch source lines by an interlayer connecting source line.

Wiring structure of source line used in semicustom integrated circuit

Bi-CMOS output circuit with limited output voltage

An ECL circuit is designed such that at the beginning of the falling of the output level, the current flowing to an output terminal is rapidly led in the direction where it will be reduced, the potential of the output terminal at this time is directly detected, and a pull down transistor is controlled through a feedback loop, thus assuring high-speed operation and low power consumption. A control circuit is provided to regulate the collector current of the pull down transistor, which is used to drop the level of the potential at the output terminal. This control circuit is so designed that the base current of the pull down transistor is controlled by the operation of another, single transistor, and no capacitor which will obstruct the circuit integration is employed to drive the pull down transistor. The structure of this circuit is therefore advantageous in realizing higher integration.

Growing community of inventors

Yokosuka, Japan

Takeshi Sugoh