International Business Machines Corporation

Wilfried Klein

Knut K Najmann

Siegfried K Wiedmann

Klaus Heuber

Friedrich C Wernicke

Erich Klink

Helmut H Heimeier

Rolf Remshardt

Volker Rudolph

Horst H Berger

Rudolf Brosch

Disclosed is a phase splitter with integrated latch circuit, where the complementary output signals generated after an input signal applied to a true-complement generator are available directly without any load by the latch circuit, where upon a premature change of the input signal there is no undesired change of the previously set switching state or of the output signals, respectively, and where a simple clocking for functional control can be used. The advantages presented by the disclosed Phase splitter substantially consist in that the speed with which the complementary output signals are supplied is extremely high since the output signals are available directly, i.e. with only one stage delay, the latch circuit being non-conductive in the stationary state, and thus in a latching process does not have to be switched from one stage to the other, but only switched on.

Phase splitter with integrated latch circuit

After a controlled strong lowering of the word line potential for the purpose of addressing a cell, said potential is immediately recharged simultaneously increasing the potential on the N side of the two PNP injectors of the cell and causing the injector capacitances of the selected storage cells and the bit line capacitances to form a capacitive voltage divider, so that the bit lines connected thereto are recharged to different degrees by the different magnitudes of the injector capacitances. Thus, the differential signal formed on the bit lines is noticeably amplified by the supply of currents of different magnitudes.

Circuit arrangement for capacitive read signal amplification in an

An integrated semiconductor memory having memory cells which have (or are designed to have) inherent asymmetrical access times for the distinguishable memory states thereof. The memory is operated on the basis of the shorter access time. This is accomplished by utilizing an oppositely asymmetrical sense system, preferably in the form of a pre-set sense latch. For example, in the case of a digital memory with the reading of a '0' state having a shorter access time than the reading of a '1' state, at the beginning of a read operation a sense latch is set to the (slower) '1' state. Thus, only in the case of reading a '0' is the state of the latch changed to the '0' state. Thus, the actual access time is no longer determined by the longer access time, namely, the reading of a '1'. The access time is determined by the shorter access time, namely, the reading of a '0'. The concept may also be used if the sense latch has an asymmetric access time. Then it is advantageous to intentionally choose a corresponding asymetrical memory cell design.

Integrated semiconductor memory and method of operating same

In an integrated circuit an improved highly integrated semiconductor structure for providing a Schottky diode-resistor circuit configuration is disclosed. Although not limited thereto, the improved highly integrated semiconductor structure has particular utility when employed in a monolithic memory.

Highly integrated semiconductor structure providing a diode-resistor

A memory storage system which utilizes semiconductor storage cells comprised of cross-coupled bipolar transistors arranged in a memory system array with an error reference circuit and a standby reference circuit that is controlled by a clock signal. The standby reference circuit and the error reference circuit are both coupled to the bit lines and selectively control a restore circuit that maintains, in the standby state, a selected potential on the bit lines such that short access times are realized and current is prevented from flowing into unselected cells when adjacent defective cells are being read or written.

Memory storage array with restore circuit

The invention relates to a circuit arrangement for operating the read/write cycles of an integrated semiconductor memory storage system whose storage cells consist of flip flops with bipolar switching transistors, Schottky diodes as read/write elements coupling the cell to the bit lines, and high-resistivity resistors, or transistors controlled as current sources, as load elements, in several phases. This is accomplished through coupling the storage cell to both read/write circuits and restore/recovery circuits via the bit lines and by selective pulsing of the cell with the read/write circuits and the restore/recovery circuits. This permits high speed, low operating current, large scale memory systems to be built.

Circuit arrangement for operating a semiconductor memory system

An improved method of operating a monolithic memory together with novel and efficient circuitry for practicing said improved method is disclosed. In a bipolar transistor store, or monolithic memory, in accordance with the invention, a very low current (first level) flows from the load elements to the internal cell nodes in the stand-by mode. During the initial portion of a read cycle, current flows from the bit lines to the cell nodes, in addition to the stand-by current (second level). In the recovery period of the read cycle or write cycle a short pulse is added to the stand-by current (third level), thereby reducing the recovery time. The practice of the invention provides a monolithic memory having minimal power requirements and a substantially reduced cycle time.

Read/write speed up circuit for integrated data memories

This teaches a sense circuit for an integrated memory storage system in which the storage cell output is detected by a differential amplifier, controlling a flip-flop, serving as a latch, having load elements which also function as the load elements of the latch to ensure an optimum power and speed product. The latch can be coupled to an output driver circuit through a current switch which shares common elements with the latch to assure that the latch remains symmetrical even when used with an output driver having asymmetrical control.

Sense circuit for memory storage system

Modern bipolar cross coupled memory cells for high density arrays use diodes as coupling elements from the cell to the bit lines. The write operation of these cells requires a high amount of current if the current gain of the cell transistors is high. The time required to perform a write operation is prolonged significantly due to the inherent capacitors in the cell known as the Miller effect. The described circuit completely eliminates the Miller effect during the write operation and makes the required write current completely independent of the current gain of the cell transistors. In the present invention this is accomplished by dropping the word line of such a cell from a stand-by potential to a select potential, so that the inner cell nodes are equally discharged, without disturbing the state of the cell, after which the word line is pulsed up to an intermediate potential between the select potential and the stand-by potential.

Write speed-up circuit for integrated data memories

A method and circuit arrangement for operating an information store, in particular a monolithic information store, whose storage cells and address circuits comprise bipolar transistors which are not continuously subjected to full power. The monolithic information store is readily fabricated by known planar process technology, has increased density, has reduced read/write times, reduced cycle time, and reduced power dissipation.

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Holzgerlingen, Germany

Wilfried Klein