Browse Prior Art Database

Monolithic Memory Cell

IP.com Disclosure Number: IPCOM000092075D
Original Publication Date: 1968-Aug-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 26K

Publishing Venue

IBM

Related People

Wiedman, S: AUTHOR

Abstract

This memory cell, comprising a bipolar transistor flip-flop, is monolithic. Transistors T1 and T2, linked on the emitter side and connected to voltage V through high-resistivity collector resistors, are cross-coupled. Such is in the form of a flip-flop through emitter-follower T3 or T4 between the collector of one and the base of the other transistor. Due to additional amplification of the emitter-followers, a low current amplification is required for T1 and T2 so that these can be inversely operated in a joint insulated region.

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Monolithic Memory Cell

This memory cell, comprising a bipolar transistor flip-flop, is monolithic. Transistors T1 and T2, linked on the emitter side and connected to voltage V through high-resistivity collector resistors, are cross-coupled. Such is in the form of a flip-flop through emitter-follower T3 or T4 between the collector of one and the base of the other transistor. Due to additional amplification of the emitter- followers, a low current amplification is required for T1 and T2 so that these can be inversely operated in a joint insulated region.

In a second insulated region, T3 and T4 are provided with two additional emitters for writing and reading stored information. Their base diffusions are extended and interconnected, serving outside the transistor structures as high- resistivity, pinch-type collector resistors. By metallizations, the base diffusion between the two resistors is linked with the N+ emitter diffusions coating the pinch resistors. The connected N- epitaxial layer, incorporating the collectors of T3 and T4, carries voltage V for the collector potential of the emitter-followers and the supply voltage of the first transistors through the subcollector underpass resistor.

In a memory matrix, only two insulated regions are required for several cells,
i.e., one word. These cells receive voltage through a joint subcollector underpass which also serves to address the cells by word line W. Information is read and written respectively through the se...