Taiwan Semiconductor Manufacturing Comp. Ltd.

Hon-Jarn Lin

Chia-Fu Lee

Yu-Der Chih

Yi-Chun Shih

Ku-Feng Lin

Po-Hao Lee

Kuo-Ching Huang

Yu-Wei Ting

Chun-Yang Tsai

A reference circuit for generating a reference current includes a plurality of resistive elements including at least one magnetic tunnel junction (MTJ). A control circuit is coupled to a first terminal of the at least one MTJ and is configured to selectively flow current through the at least one MTJ in the forward and inverse direction to generate a reference current.

MRAM reference current

A memory cell includes a memory circuit and a multiplier circuit. The multiplier circuit includes an output node configured to output the output signal, a first transistor and an initialization circuit. The first transistor is coupled to the output node and the memory circuit, and is configured to receive at least the second signal. The initialization circuit is coupled to the first transistor by the output node, and is configured to initialize the multiplier circuit in response to at least a third signal or a fourth signal. The memory circuit is configured to store a first value of a first signal of a first storage node. The multiplier circuit is coupled to the memory circuit. The multiplier circuit is configured to generate an output signal in response to the first signal and a second signal. The output signal corresponds to a product of the first signal and the second signal.

Memory cell and method of operating the same

A sense amplifier is provided. A first terminal of a first invertor is connected to a power node and a second terminal of the first invertor is connected to a cell current source. A first terminal of a second invertor is connected to the power node and a second terminal of the second invertor is connected to a reference current source. The first invertor is cross coupled with the second invertor at a first node and a second node. A pre-charge circuit is connected to the first node and the second node. A first pull up transistor and a second pull up transistor are connected between a supply voltage node and the power node. A signal level detector circuit is connected to the second pull up transistor. The signal level detector circuit switches on the second pull up transistor when a remaining voltage on one of the first node and the second node is below a reference voltage.

Sense amplifier

A circuit includes cross coupled invertors including a first invertor and a second inventor. The first invertor and the second invertor are cross coupled at a first data node and a second data node. An input unit is coupled between the cross-coupled invertors and a power node. The input unit controls the cross-coupled invertors in response to a first input signal received at a first input terminal of the input unit and a second input signal received at a second input terminal of the input unit. A first transistor is connected between the power node and a supply node. The first transistor connects the power node to the supply node in response to an enable signal changing to a first value. A second transistor is connected between the power node and ground. The second transistor connects the power node to the ground in response to the enable signal changing to a second value.

Latch

A device includes first and second reference storage units, and first and second reference switches. The first reference switch outputs a first current at a first terminal thereof to the first reference storage unit. The first reference storage unit receives the first current at a first terminal thereof and generates a first signal, according to the first current, at a second terminal thereof to an average current circuit. The second reference switch outputs a second current at a first terminal thereof to the second reference storage unit. The second reference storage unit receives the second current at a first terminal thereof, and generates a second signal, according to the second current, at a second terminal thereof to the average current circuit. The first and second reference switches are coupled to a plurality of first memory cells by a first word line.

Memory device and reference circuit thereof

A method for sensing logical states of memory cells in multiple segments in a memory device, each cell having a high- and low-resistance state, resulting in different cell current levels for the different resistance states. The method includes determining target reference current levels for the respective segments, at least two of the target reference current levels being different from each other; generating a reference current for each segment with the target reference current level for that segment; comparing the cell current level for each cell to the reference current level for the segment the cell is in; and determining the logical states of the memory cells based on the comparison.

Segmented reference trimming for memory arrays

A device includes a first reference storage unit, a second reference storage unit, a first reference switch, and a second reference switch. The first reference switch includes a first terminal coupled to a first reference bit line, a second terminal coupled to the first reference storage unit, and a control terminal coupled a reference word line. The second reference switch includes a first terminal coupled to a second reference bit line, a second terminal coupled to the second reference storage unit, and a control terminal coupled the reference word line. The first reference storage unit is configured to receive a bit data through the first reference switch, and to generate a first signal having a first logic state.

A device includes memory cells, a first reference switch, a second reference switch, a first reference storage unit, a second reference storage unit, and an average current circuit. The memory cells are each configured to store corresponding bit data. The first reference switch and the second reference switch are turned on when a word line is activated. The first reference storage unit generates a first signal having a first logic state when the first reference switch is turned on. The second reference storage unit generates a second signal having a second logic state when the second reference switch is turned on. The average current circuit averages the first signal and the second signal to generate a reference signal to be compared with a current indicating the bit data of one memory cell, in order to determine a logic state of the bit data of the memory cell.

An integrated chip is disclosed. In some embodiments, the integrated chip includes a plurality of resistive random access memory (RRAM) devices respectively having a first electrode and a second electrode. A bit-line decoder is connected to the first electrode of the plurality of RRAM devices by a plurality of bit-lines. A current limiting element is connected to the second electrode of the plurality of RRAM devices by way of a plurality of access transistors. The current limiting element is configured to concurrently limit currents on the plurality of bit-lines.

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Taipei, Taiwan

Hon-Jarn Lin