Stmicroelectronics Gmbh

Duane Giles Laurent

James Brady

James Leon Worley

Elmer H Guritz

An apparatus and method is provided that reduces the propagation delay in a conductor carrying an electrical signal from a first area of a circuit to a second area of the circuit. The conductor is fabricated to include a first conductor extending from the first area to the second area. The conductor also includes a second conductor extending substantially parallel and along the first conductor and electrically connected to the first conductor. A third and additional conductors may also be used which extend substantially parallel and along the first conductor and are electrically connected to the first conductor. The additional second conductor (and any additional conductors) reduces the capacitance of the conductor thereby reducing the propagation delay in the conductor (increasing the speed of the signal). The additional conductor(s) effectively 'shield' the first conductor from some capacitance that the first conductor would normally 'see' without the use of such additional conductors.

Apparatus and method for reducing propagation delay in a conductor system selectable to carry a single signal or independent signals

A dynamic random access memory (DRAM) includes a bit line pair, including a first bit line and a second bit line. Memory cells and a sense amplifier are coupled to the bit lines. A first characterization cell is coupled between the first bit line and a first reference supply line. The first characterization cell includes a capacitor. Similarly, a second characterization cell is coupled between the first bit line and the first reference supply line. The second characterization cell also includes a capacitor but preferably with a different capacitance. In the preferred embodiment, similar characterization cells are coupled to the second bit line.

Method and circuit for determining sense amplifier sensitivity

Apparatus and method for reducing propagation delay in a conductor

A circuit and method are disclosed for reducing soft errors in dynamic memory devices using error checking and correcting. In an exemplary embodiment, a memory device includes a dual port memory having a first port for externally-initiated memory access operations and a second port for handling memory access operations associated with error checking and error correction operations. An error module, coupled to the second port of the dual port memory, performs an error checking operation on words read from the dual port memory. An error controller, coupled to the error module, controls the error module to perform error check operations on each word sequentially read from the dual port memory through the second port thereof. The error checking is performed substantially in parallel with externally-initiated memory access operations performed using the first port of the dual port memory. The error module may also generate a corrected word for a word that is detected by the error module as having a correctable error. The error controller may replace in the dual port memory the word having the correctable error with the corrected word.

System and method for correcting soft errors in random access memory devices

A circuit is disclosed for monitoring a reference voltage generated in a semiconductor memory device to facilitate a memory access operation. The circuit utilizes a pair of Schmitt trigger circuits. A first of the Schmitt trigger circuits detects the voltage appearing on the output of a reference voltage generator falling below a minimum threshold voltage level. A second of the Schmitt trigger circuits detects the output voltage of the reference voltage generator exceeding a maximum threshold voltage level. The circuit may further include reset circuitry for initially placing predetermined voltage levels on the inputs of the Schmitt trigger circuits. An output circuit receives the output of each Schmitt trigger circuit and generates an output signal having a value indicative of whether the output of the reference voltage generator is not within an acceptable voltage range.

Voltage detection circuit and method for semiconductor memory devices

A circuit and method are disclosed for controlling bootstrap circuitry that boosts a voltage level appearing on word lines of a dynamic random access memory device. During execution of a memory access operation, the circuit is adapted to enable the bootstrap circuitry a period of time following the memory device's sense amplifiers initially powering up. The circuit senses when the voltage appearing on a select bit line crosses a predetermined voltage level, and enables the bootstrap circuitry thereafter. In this way, a period of time elapses between the sense amplifiers turning on and the activation of the bootstrap circuitry, thereby reducing noise introduced from the sense amplifiers turning on from impacting the operation of the bootstrap circuitry.

Bit line sense circuit and method for dynamic random access memories

Composite layers of titanium silicide and polysilicon define a fuse resistor within a programmable fuse element that increases its resistance from about 50 ohms in the unprogrammed state to about 250 K-ohms in the programmed state by creating a discontinuity in the silicide layer immediately over a PN junction in the polysilicon layer. The resistance of the fuse resistor in the programmed state is determined by the reverse-biased diode characteristic of the PN junction. Portions of a metallic layer overlie portions of the fuse resistor except at the site of the PN junction in the polysilicon layer so that the silicide is preferentially heated immediately above the PN junction to cause the discontinuity to occur at that site. The metallic layer portions serve both as a heat sink for the underlying portions of the silicide layer and as electrical connections to the fuse resistor.

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Lewisville, TX, United States of America

Duane Giles Laurent