Write circuit for phase change memories and write method thereof

Abstract

The invention discloses a write circuit for phase change memories. The write circuit is characterized in that an output end of an adjustable square-wave voltage pulse circuit is connected to an input end of a first switch circuit; a second end of the first switch circuit is connected with a first end of a phase change resistor and a first end of a second switch circuit; a second end of the phase change resistor is connected with a drain electrode of a gate tube; a source electrode of the gate tube and a second end of the second switch circuit are respectively grounded; the adjustable square-wave voltage pulse circuit outputs a first voltage pulse satisfying a SET operation in the process of executing the SET operation, and outputs a second voltage pulse satisfying a RESET operation in the process of executing the RESET operation; the first switch circuit is closed when the SET operation and the RESET operation are executed; the second switch circuit is disconnected when the SET operation and the RESET operation are executed, and closed when the RESET operation is completed; and the gate tube is conducted when the SET operation and the RESET operation are executed. The invention also discloses a write method of the write circuit. The circuit and method disclosed by the invention are simple and easy to implement, and the complexity of the write circuit is significantly reduced.

Description

technical field [0001] The invention relates to a phase-change memory, in particular to a writing circuit and a writing method of the phase-change memory. Background technique [0002] Due to the fast read and write speed and long data retention time of the phase change memory, it has been developed rapidly in recent years. [0003] Reading and writing of phase change memory can be realized by applying different voltage or current pulses. The write operation is divided into a set (SET) operation and a reset (RESET) operation to complete the transformation of the two states of low resistance and high resistance. [0004] When performing RESET operation, a higher voltage or current pulse needs to be applied, which will raise the temperature of the phase change material above the melting temperature by generating a certain amount of heat, and then rapidly cool and crystallize to form a high-resistance state. When performing SET operation, a medium-intensity voltage or current...

AI Technical Summary

Problems solved by technology

[0007] Depend on figure 1 It can be seen that the existing writing circuit is relatively complicated, but for large-scale capacity storage, in order to make the writing speed very fast, the number of bits written each time is more, and one bit corresponds to a GST phase-change resistor 16, so The required write circuits will also increase accordingly, the more the number of current mirrors required, the greater the power consumption generated by the current mirrors, and the larger the layout area occupied by the current mirrors.

[0008] In addition, considering different process conditions, when producing chips, the matching of the current mirror will also have deviations in the magnitude of the generated current. In the actual production process, to achieve accurate current replication, especially when the required When there are many current mirrors, it will be more difficult to generate precise current

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