Reference current generating circuit and generating method for EEPROM memory

Abstract

The invention relates to a reference current generating circuit for an EEPROM memory, comprising a storage unit and a mirror unit. The storage unit is configured to output a standard current I0_cell to the mirror unit, the mirror unit is configured to process the standard current I0_cell and output a current m*I0_cell as a reference current Iref, wherein m is 0 (m (1; and a reference current generating method is disclosed). The reference current Iref is associated with the standard current I0_cell to ensure that the reference current Iref always satisfies a formula (1.3), and the current difference brought by a process, the temperature and the like can be reduced as much as possible; a reference CELL is shared in the memory as a reference current source, and the required area is small compared to the conventional current detecting circuit; the reference current Iref generated by this circuit is a relative current, which varies with changes in voltage, temperature and process angle, andsatisfies the formula (1.3) regardless of any change, so that the anti-interference ability and the accuracy of the subsequent read performance can be ensured.

Description

technical field [0001] The invention relates to the technical field of nonvolatile memory, in particular to a reference current generating circuit and a generating method for EEPROM memory. Background technique [0002] At present, the data detection mechanism of the EEPROM reading circuit is generally based on the method of current detection, and its core idea is to convert the conduction current I of EE_CELL to cell with reference current I ref Compare to get the type of storage unit, namely: [0003] I cell > I ref , 0_cell (1.1) [0004] I cell <I ref , 1_cell (1.2) [0005] figure 1 , figure 2 These are two traditional read circuits based on the current detection mechanism. The general idea of ​​these two circuits is that the comparison current is generated by a reference circuit, and a high-performance reference requires a high-gain, high-power differential op amp. In order to ensure the correctness of the read data, usually, it is necessary to ensure ...

AI Technical Summary

Problems solved by technology

Since the reference current I ref The production of MOS tube or triode BJT is usually produced, which is not the same type of device as EE_cell, so that I ref with I cell The matching of is difficult, from figure 1 and figure 2 It can be seen that a separate reference current source or reference voltage source will increase the system development cost (chip area, development and design cycle), and the verification current actually required by the memory unit will fluctuate with the process deviation (process angle FF / TT / SS ), this kind of fluctuation leads to chips produced in different batches of different wafers, the check point will not always be near the optimal value, thus affecting the reading performance (error, speed, anti-interference)

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