Ias voltage generator for reference cell and bias voltage providing method therefor

Abstract

A bias voltage generator and generating method for a reference cell are provided. The bias voltage generator includes a data read detector, a cut-off signal generator and an output stage circuit. The data read detector generates a detection signal according to transition points of a sense amplifier enable signal and a sense amplifier latch signal. The cut-off signal generator delays the detection signal a delay time to generate a cut-off signal, wherein a start-up time of the cut-off signal is decided by the detection signal and the delay time. The output stage circuit starts or stops to provide a bias-voltage providing signal according to the cut-off signal.

Description

BACKGROUND[0001]1. Field of the Invention[0002]The invention is directed to a serial interface flash memory and more particularly, to a bias voltage generator for a reference cell adapted to a serial interface flash memory.[0003]2. Description of Related Art[0004]In the technical field of the related art, when performing a read operation on a serial interface flash memory, a bias voltage applying operation requiring to be performed on a gate of the reference cell would cause an effect of read disturb. The read disturb is relevant to an amount of the voltage level biased by the gate of the reference cell and the length of the bias voltage. Moreover, the read disturb causes reduction of a read margin of the serial interface flash memory, so that the performance of the serial interface flash memory is influenced.[0005]In the technical field of the related art, the bias voltage applied to the reference cell in the serial interface flash memory is sequentially applied to a gate of the re...

AI Technical Summary

Benefits of technology

The invention is about a device that generates a bias voltage for a reference cell in a flash memory to prevent read-disturbs. The device automatically adjusts the bias voltage when the memory is operating at a low frequency. This helps to improve the reliability and performance of the flash memory.

Problems solved by technology

In the technical field of the related art, when performing a read operation on a serial interface flash memory, a bias voltage applying operation requiring to be performed on a gate of the reference cell would cause an effect of read disturb.

A situation where the bias voltage applying operation is received for a long term commonly leads to deterioration of the memory cell.

Specially, when the serial interface flash memory is operated in a low operation frequency, a time length for the bias voltage applied to the reference cell is longer, and as a result, damages caused to the reference cell would become worse.

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