Texas Instruments Corporation

Motorola Corporation

Other

Sudhir Kumar Madan

Hugh Pryor McAdams

Sung-Wei Lin

John Y Fong

Anand Seshadri

Jarrod Eliason

David J Toops

Hugh P Mcadams

Theodore Warren Houston

Bryan David Sheffield

Robert J Landers

Stephen S Poon

Jeffrey L Klein

Suresh Balasubramanian

Juergen T Rickes

Bob D Strong

Mark S Swenson

A method of maintaining a power supply voltage during a brownout is disclosed. The method includes the step of storing a charge in a charge reservoir () and storing a charge on a power supply capacitor (). A charge from the charge reservoir is applied to the power supply capacitor in response to a power supply fail signal (BROWNOUT).

Method to maintain power supply voltage during brownout

A memory circuit to reduce active power is disclosed (FIG.). The circuit includes a sense amplifier (). A first bit line (BL) is coupled to a memory array. A second bit line (BLB) that is a complementary bit line to the first bit line is also coupled to the memory array. A first transistor (TG) is coupled between the first bit line (BL) and the sense amplifier. A second transistor (TG) is coupled between the second bit line (BLB) and the sense amplifier. A first drive circuit () is coupled between the sense amplifier and the first bit line and is operable to drive a first data signal from the sense amplifier onto the first bit line when the second transistor is off.

Single sided bit line restore for power reduction

A method of reducing leakage current in a memory circuit is disclosed (FIG.A). The method includes connecting a first supply voltage terminal (VDD) to a bulk terminal of a transistor in an active mode of operation. The method further includes detecting a low power mode (SLEEP) of operation of the transistor and disconnecting the first supply voltage terminal from the bulk terminal in response to the step of detecting.

Power reduction circuit and method

A method of reading a memory cell. The method includes the step of connecting () a reference voltage generator () to a first bitline (/BL). The first bitline is charged to a reference voltage (VREF) from the reference voltage generator. The reference voltage generator is disconnected (RFWL_A/B low at t, FIG.B) from the first bitline. A signal voltage (PL high at t, FIG.B) from the memory cell is applied to a second bitline (BL) after the step of disconnecting. A difference voltage between the first and second bitlines is amplified (SAEN high at t, FIGS.A andB).

Method of reading a ferroelectric memory cell

An integrated circuit containing a memory array, a redundancy circuit and a redundancy error correction circuit coupled to said redundancy circuit. A method for constructing a redundancy word which corresponds to each memory segment and a method for error checking the redundancy word during a memory access request.

High reliability and low power redundancy for memory

A static RAM redundancy memory for use in combination with a non-volatile memory array, such as ferroelectric RAM (FRAM), in which the power consumption of the SRAM redundancy memory is reduced. Each word of the redundancy memory includes data bit cells for storing addresses of memory cells in the FRAM array to be replaced by redundant elements, and also enable bits indicating whether redundancy is enabled for those addresses. A logical combination of the enable bits in a given word determines whether the data bit cells in that word are powered-up. As a result, the power consumption of the redundancy memory is reduced to the extent that redundancy is not enabled for segments of the FRAM array.

Low-power redundancy for non-volatile memory

A solid-state memory such as a ferroelectric random access memory (FeRAM) with multiplexed internal data bus and reduced power consumption on data transfer. The memory stores data in the form of multi-byte data words with error correction coding (ECC). In a page mode read/write operation, data states stored in memory cells of the selected row are sensed by sense amplifiers arranged in first and second banks, which are associated with first and second groups of columns. The first bank of sense amplifiers, associated with the first group of columns and containing the ECC value, are coupled to to the internal bus, followed by coupling the second bank of sense amplifiers associated with the second group of columns to the internal bus. The internal bus is then placed in tri-state, following which the internal data bus is driven with data to be written into the second group of columns in that same row, that data latched into the second bank of sense amplifiers. The internal bus is then driven with the data to be written to the first group of columns in the row, and latched into the first bank of sense amplifiers. To the extent that the data in the second group of columns does not change from the read to write operations, power consumption otherwise necessary for switching the internal bus is avoided.

Data path read/write sequencing for reduced power consumption

An integrated circuit containing a nonvolatile memory circuit which contains memory segments and sense amplifier banks individually powered by a power decoder circuit. A method of accessing a portion of a powered-down memory.

Memory array power domain partitioning

One embodiment relates to a ferroelectric memory device. The ferroelectric memory device includes a segment of contiguous ferroelectric memory cells arranged in rows and columns. A row of ferroelectric memory cells includes a common wordline that allows access to the memory cells of the row and also includes at least two platelines associated with the row. At least one of the at least two platelines is associated with adjacent columns of ferroelectric memory cells within the row. The row of ferroelectric memory cells includes another word line which is not associated with the at least two platelines. Other methods and systems are also disclosed.

Ferroelectric memory devices with partitioned platelines

One embodiment relates to an integrated circuit that includes a ferroelectric memory cell. The ferroelectric memory cell includes a ferroelectric capacitor having a first plate and a second plate. The first plate is associated with a storage node of the ferroelectric memory cell, and the second plate associated with a plateline. The ferroelectric memory cell also includes a complementary transmission gate configured to selectively couple the storage node to a bitline as a function of a wordline voltage and a complementary wordline voltage. Bias limiting circuitry selectively alters voltage on the storage node as a function of the wordline voltage or the complementary wordline voltage. Other methods, devices, and systems are also disclosed.

Ferroelectric memory cell with access transmission gate

One embodiment relates to a ferroelectric memory device. The ferroelectric memory device includes a memory array comprising one or more ferroelectric memory cells that are arranged in a number of plateline groups. The memory device also includes a plateline driver configured to boost a plateline voltage above a supply voltage within the plateline driver, and provide the boosted plateline voltage along platelines associated with the plateline driver. Other methods and systems are also disclosed.

Plateline driver for a ferroelectric memory

One aspect of the invention relates to a method for accessing a memory device. One embodiment relates to a method for accessing a memory device. In the method during a read operation, one data value is provided on a local IO line while complimentary local IO line that is associated with the local IO line is inactivated. During a write operation, another data value is provided on the local IO line and a complimentary data value is provided on the complimentary local IO line. Other systems and methods are also disclosed.

Methods and systems for accessing memory

Memory devices are provided, having a ferroelectric memory array and a zero cancellation system with one or more zero cancellation circuits for coupling a negative charge to a memory array bitline through a zero cancellation capacitor while a memory cell plateline signal is applied during a read operation, wherein one or more layers of the zero cancellation system layout is identical or substantially identical to that of the memory cells of the array.

Ferroelectric memory array for implementing a zero cancellation scheme to reduce plateline voltage in ferroelectric memory

Methods are described for operating a FeRAM and other such memory devices in a manner that avoids over-voltage breakdown of the gate oxide in memory cells along dummy bit lines used at the edges of memory arrays, the methods comprising floating the dummy bit line during plate line pulsing activity. In one implementation of the present invention the method is applied to a FeRAM dummy cell having a plate line, a dummy bit line, a pass transistor, and a ferroelectric storage capacitor. The method comprises initially grounding the dummy bit line as a preferred pre-condition, however, this step may be considered an optional step if the storage node of the storage capacitor is otherwise grounded. The method then comprises floating the dummy bit line, activating a word line associated with the memory cell, and pulsing the plate line. Alternately, the method comprises applying a positive voltage bias to the dummy bit line in place of, or before floating the dummy bit line. The method may further optionally comprise grounding the dummy bit line after pulsing the plate line, and optionally disabling the word line after grounding the dummy bit line to precondition the cell for the next memory operation.

Active float for the dummy bit lines in FeRAM

An FeRAM memory array wherein the plate lines run in the direction of word lines is described that provides a reduced plate line resistance in arrays having a common plate line connection. The lower plate line resistance reduces the magnitude of negative spikes on the plate line to reduce the potential for FeCap depolarization. Two or more plate lines of a plurality of columns of memory cells are interconnected along a bit line direction. Some or all of the plate lines of one or more columns of dummy memory cells may also be interconnected to reduce the plate line resistance and minimize any increase in the bit line capacitance for the active cells of the array. The improved FeRAM array provides a reduced data error rate, particularly at fast memory cycle times.

Growing community of inventors

Richardson, TX, United States of America

Sudhir Kumar Madan