Browse Prior Art Database

Integrated Circuits

IP.com Disclosure Number: IPCOM000092236D
Original Publication Date: 1968-Oct-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Heneghan, MJ: AUTHOR

Abstract

Because of the small size of a semiconductor chip, maximum utilization of chip output terminals is sought. Electrical conductors connecting different chips are required to carry high-frequency signals and thus, in many cases, constitute transmission lines. Generally, a chip output terminal is driven by an emitter-follower stage having or not having an emitter resistor. This depends upon the length of the transmission line employed to interconnect different chips. Advantageous utilization of a chip output terminal is obtained by selectively inserting or removing an emitter resistor connected to a single chip output terminal, thus eliminating the use of an additional chip output terminal.

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Integrated Circuits

Because of the small size of a semiconductor chip, maximum utilization of chip output terminals is sought. Electrical conductors connecting different chips are required to carry high-frequency signals and thus, in many cases, constitute transmission lines. Generally, a chip output terminal is driven by an emitter- follower stage having or not having an emitter resistor. This depends upon the length of the transmission line employed to interconnect different chips. Advantageous utilization of a chip output terminal is obtained by selectively inserting or removing an emitter resistor connected to a single chip output terminal, thus eliminating the use of an additional chip output terminal.

Chip 10 comprises a plurality of circuits 12, and 14 and 16, shown generally, connected to their respective emitter-follower outputs 18, 20, and 22. Chip output terminals 24, 26, and 28 are connected to each of the respective emitter- follower output circuits. Control line 30 is adapted to receive a switching voltage at terminal 32 so as to selectively insert or remove the plurality of emitter resistors R. Such is effected by appropriately biasing diodes D1, D2, and D3 connected in the respective emitter-follower output circuits 18, 20, and 22.

A negative biasing source, not shown, applied to terminal 32, forward biases D1, D2, and D3 so as to insert the plurality of resistors R into their respective chip terminals 24, 26, and 28. Similarly, a positive biasing...