Patent application number | Description | Published |
20090021292 | RELIABLE LEVEL SHIFTER OF ULTRA-HIGH VOLTAGE DEVICE USED IN LOW POWER APPLICATION - The present invention relates to integrated circuits. In particular, it relates to an IC comprising a receiving stage for receiving an input signal, an output stage for generating an output signal having a larger voltage range than the input signal and a level shifter. Embodiments of the invention provide a structure and a method for fabricating the IC wherein the level shifter is incorporated within the IC to improve reliability of the IC. | 01-22-2009 |
20120119823 | Bias Circuit with High Enablement Speed and Low Leakage Current - A circuit includes a first and a second PMOS transistor, wherein a gate of the second PMOS transistor is coupled to a gate and a drain of the first PMOS transistor; a first NMOS transistor having a drain coupled to a drain of the first PMOS transistor; and a second NMOS transistor, wherein a drain of the second NMOS transistor is coupled to a gate of the first NMOS transistor, a gate of the second NMOS transistor, and a drain of the second PMOS transistor. A first switch is coupled between the drain of the first PMOS transistor and the drain of the second PMOS transistor. A second switch is coupled between a source of the first NMOS transistor and an electrical ground. A third switch is coupled between a source of the second NMOS transistor and the electrical ground. | 05-17-2012 |
20130070519 | READ ARCHITECTURE FOR MRAM - A read architecture for reading random access memory (RAM) cells includes a multi-level sense amplifier, the multi-level sense amplifier including a plurality of sense amplifiers, each sense amplifier having a respective sense threshold and a respective sense output, and a storage module coupled to the multi-level sense amplifier for storing the sense outputs of the multi-level sense amplifier. The storage module stores a first set of sense outputs corresponding to a first read of an RAM cell and stores a second set of sense outputs corresponding to a second read of the RAM cell. The architecture also includes a decision module for comparing the first and second set of sense outputs and determining a data state of the RAM cell based on the comparison. | 03-21-2013 |
20130188418 | MAGNETORESISTIVE RANDOM ACCESS MEMORY - A magnetoresistive random access memory (MRAM) cell includes a magnetic tunnel junction (MTJ), a top electrode disposed over the MTJ, a bottom electrode disposed below the MTJ, and an induction line disposed above or below the MTJ. The induction line is configured to induce a magnetic field at the MTJ. | 07-25-2013 |
20130201754 | MRAM WITH CURRENT-BASED SELF-REFERENCED READ OPERATIONS - A magnetoresistive memory stores logic values in high and low resistance states of magnetic tunnel junction elements. Instead of comparing the resistance of elements to a fixed threshold to discern a logic state, the resistances of elements are self-compared before and after imposing a low resistance state. A measure of the resistance of an element in its unknown resistance state is stored, for example by charging a capacitor to a voltage produced when read current bias is applied. Then the element is written into its low resistance state and read current bias is applied again to develop another voltage, representing the low resistance state. A comparison circuit using current summing and an offset providing a minimum difference tolerance determines whether the resistance of the element was changed or remained the same. This determines the logic state of the element. | 08-08-2013 |
20130242676 | FAST-SWITCHING WORD LINE DRIVER - A word line driver of a semiconductor memory includes logic circuitry for coupling a word line to a first node set at a first voltage level when the word line driver is in a first state or to a second node set at a second voltage level when the word line driver is in a second state. A capacitor is configured to be charged to a third voltage level that is greater than the first and second voltage levels. First and second transistors are configured to selectively couple the word line to the capacitor and to a third node set at a fourth voltage level when the word line driver is in a third state. The fourth voltage level is greater than the first voltage level and less than the second voltage level. | 09-19-2013 |
20130265820 | ADJUSTING REFERENCE RESISTANCES IN DETERMINING MRAM RESISTANCE STATES - Magneto-resistive memory bit cells in an array have high or low resistance states storing logic values. During read operations, a bias source is coupled to an addressed memory word, coupling a parameter related to cell resistance to a sense amplifier at each bit position. The sense amplifiers determine whether the parameter value is greater or less than a reference value between the high and low resistance states. The reference value is derived by averaging or splitting a difference of resistances of reference cells at high and/or low resistance states. Bias current is conducted over address lines with varying resistance, due to different distances between the sense amplifiers and addressed memory words, which is canceled by inserting into the comparison circuit a resistance from a dummy addressing array, equal to the resistance of the conductor addressing the selected word line and bit position. | 10-10-2013 |
20130272059 | DIFFERENTIAL MRAM STRUCTURE WITH RELATIVELY REVERSED MAGNETIC TUNNEL JUNCTION ELEMENTS ENABLING WRITING USING SAME POLARITY CURRENT - A magnetoresistive memory has first and second magnetic tunnel junction (MTJ) elements operated differentially, each with a pinned magnetic layer and a free magnetic layer that can have field alignments that are parallel or anti-parallel, producing differential high and low resistance states representing a bit cell value. Writing a high resistance state to an element requires an opposite write current polarity through the pinned and free layers, and differential operation requires that the two MTJ elements be written to different resistance states. One aspect is to arrange or connect the layers in normal and reverse order relative to a current bias source, thereby achieving opposite write current polarities relative to the layers using the same current polarity relative to the current bias source. The differentially operated MTJ elements can supplement or replace single MTJ elements in a nonvolatile memory bit cell array. | 10-17-2013 |
20140064000 | Fast Bit-Line Pre-Charge Scheme - A device includes a first switch configured to control a connection between a first voltage node and a capacitor, and a second switch configured to control a connection between a common charge node and the capacitor. The device further includes a plurality of bit-lines, and a plurality of bit-line charge switches, each configured to control a connection between a respective one of the plurality of bit-lines and the common charge node. | 03-06-2014 |
20140071750 | ADAPTIVE WORD-LINE BOOST DRIVER - A word line driver circuit includes a first transistor having its gate coupled to a first node configured to receive a word line select signal. A second transistor has its gate coupled to the first node and a drain coupled to a drain of the first transistor at a second node that is coupled to a word line. A word line assist control circuit is coupled to the first node, to the word line, and to a gate of a third transistor. The word line assist control circuit is configured to turn on or turn off the third transistor to adjust a voltage of the word line. | 03-13-2014 |
20140157088 | MRAM Smart Bit Write Algorithm with Error Correction Parity Bits - Some aspects of the present disclosure relate a method. The method attempts to write an expected multi-bit word to a memory location in memory. After writing of the multi-bit word has been attempted, an actual multi-bit word is read from the memory location. The actual multi-bit word is then compared with the expected multi-bit word to identify a number of erroneous bits and a number of correct bits stored in the memory location. The number of erroneous bits is re-written to the memory location without attempting to re-write the correct bits to the memory location. | 06-05-2014 |
20140211549 | ACCOMMODATING BALANCE OF BIT LINE AND SOURCE LINE RESISTANCES IN MAGNETORESISTIVE RANDOM ACCESS MEMORY - A memory has magnetic tunnel junction elements with different resistances in different logic states, for bit positions in memory words accessed by a word line signal coupling each bit cell in the addressed word between a bit line and source line for that bit position. The bit lines and source lines are longer and shorter at different word line locations, causing a resistance body effect. A clamping transistor couples the bit line to a sensing circuit when reading, applying a current through the bit cell and producing a read voltage compared by the sensing circuit to a reference such as a comparable voltage from a reference bit cell circuit having a similar structure. A drive control varies an input to the switching transistor as a function of the word line location, e.g., by word line address, to offset the different bit and source line resistances. | 07-31-2014 |
20140266312 | Sensing Circuit with Reduced Bias Clamp - A sensing circuit having a reduced bias clamp and method of operating the sensing circuit are provided. The sensing circuit may include a reference path and a sensing path. The sensing path may include a first transistor, clamping capacitor and a pair of switches. The reference path may include a second transistor, clamping capacitor and another pair of switches. A common gain stage receiving a bias voltage charges the clamping capacitors for the respective paths in a charging mode. The clamping capacitors may be charged in a serial or partially parallel manner during the charging mode. Each path may be coupled to a comparator, which may sense current or voltage changes between the paths during a sense mode. The sensing circuit may be configured to provide for sensing current or voltage changes between multiple sensing and/or reference paths in a parallel or serial manner. | 09-18-2014 |
20140269030 | METHOD AND APPARATUS FOR MRAM SENSE REFERENCE TRIMMING - A trimming process for setting a reference current used in operating an MRAM module comprising an operational MRAM cell coupled to a bit line, multiple reference MRAM cells coupled to a reference bit line, and a sense amplifier coupled to the bit line and the reference bit line is disclosed in some embodiments. The process includes applying a bit line reference voltage to the reference bit line to provide a reference cell current formed by a sum of respective currents through the plurality of reference MRAM cells. The reference cell current is detected. A determination is made as to whether the detected reference cell current differs from a target reference cell current. The bit line reference voltage is varied, or a sensing ratio of the sense amplifier is varied, if it is determined that the detected reference cell current differs from the target reference cell current. | 09-18-2014 |
20150063048 | Sample-and-Hold Current Sense Amplifier and Related Method - A device includes an amplifier and a first switched current sampler. The first switched current sampler includes a first transistor, a first capacitor, and first, second, and third switches. The first capacitor has a first terminal electrically connected to a gate electrode of the first transistor, and a second terminal electrically connected to a source electrode of the first transistor. The first switch has a first terminal electrically connected to a first current source, and a second terminal electrically connected to the gate electrode of the first transistor. The second switch has a first terminal electrically connected to the first current source, and a second terminal electrically connected to a drain electrode of the first transistor. The third switch has a first terminal electrically connected to the drain electrode of the first transistor, and a second terminal electrically connected to a first input terminal of the amplifier. | 03-05-2015 |