A multi-level temperature-controlled self-refresh memory device and method based on threshold voltage adjustment

Abstract

The invention relates to the technical field of memories and especially relates to a device and a method for threshold-voltage adjustment-based multistage temperature control self-refreshing storage. The device for threshold-voltage adjustment-based multistage temperature control self-refreshing storage comprises an oscillator, a frequency divider, a temperature sensor, and a first selector. The temperature sensor is connected to the first selector. The oscillator is connected to the frequency divider. The frequency divider is connected to the first selector. The first selector is connected to a DRAM array. The device for threshold-voltage adjustment-based multistage temperature control self-refreshing storage also comprises n substrate voltage stabilization modules and a second selector. The n substrate voltage stabilization modules produce substrate voltage VBB1 to VBBn in DRAM keeping. The second selector selects one of the substrate voltage VBB1 to VBBn under the control of a temperature voltage signal Vtemp produced by the temperature sensor and then outputs it as transistor substrate voltage of the DRAM array. The device and the method solve the prior art problems of a large temperature range corresponding to each grade frequency, a large threshold-voltage change range, and low efficiency or unreliability.

Description

technical field [0001] The invention relates to the technical field of memory, in particular to a multi-level temperature-controlled self-refresh method based on threshold voltage adjustment. Background technique [0002] DRAM can cause data corruption due to leakage current, so the data should be read out before the cell data is lost and then charged to the initial charge level. This recharging process is called refreshing. In addition, self-refresh means that the DRAM itself refreshes at a fixed period to maintain data in the memory cells in the standby state. On the other hand, the leakage current doubles for every 10°C rise in temperature. In other words, when the temperature rises by 10 degrees, the retention time of the memory cell data is reduced by 1 / 2, and when the temperature rises by 50 degrees, the retention time is reduced to 1 / 32. As described above, leakage current is closely related to temperature, therefore, temperature is an important factor affecting th...

AI Technical Summary

Problems solved by technology

[0005] The disadvantage of the existing technology is that, under normal circumstances, if it is not controlled, the refresh rate needs to be doubled every 12 degrees

The temperature range corresponding to the frequency of each stage is large, and the threshold voltage changes in a large range, which may cause low efficiency or unreliability problems

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