Erase-write voltage generation circuit

Abstract

The invention discloses an erase-write voltage generation circuit which comprises a first charge pump, a climbing circuit, an N-channel metal oxide semiconductor (NMOS) tube and a detection circuit, and also comprises a second charge pump, wherein the second charge pump is connected between the first charge pump and the climbing circuit and is used for increasing high voltage output by the first charge pump by nV, so that the NMOS tube is fully conducted when the erase-write voltage generated by a source is reduced because of overlarge load current. According to the erase-write voltage generation circuit, the first charge pump can make a quick response to the change of the erase-write voltage, so that the erase-write voltage cannot be changed too much, and the aim of precisely controlling the erase-write voltage can be fulfilled.

Description

technical field [0001] The invention relates to an erasing and writing voltage generating circuit, in particular to an erasing and writing voltage generating circuit which precisely controls the erasing and writing voltage. Background technique [0002] In flash memory circuit design, the system often needs to generate 12V high voltage for flash memory erasing. figure 1 It is a schematic circuit diagram of an erasing voltage generation circuit in the prior art. Such as figure 1 As shown, the erasing and writing voltage generation circuit includes a high-voltage charge pump 10, a ramp circuit (Gramp) 11, an NMOS tube ml, and a detection circuit 12. The output voltage Hve of the high-voltage charge pump 10 can quickly rise to 12.4V, and then the detection circuit 12 Triggered to enter the working state and control the high-voltage charge pump 10 to stop working, here the detection circuit 12 can be a comparator, one input terminal is connected to the output terminal of the h...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the problem of excessive fluctuations in the erasing voltage generation circuit in the prior art, the main purpose of the present invention is to provide an erasing voltage generation circuit, which adds a The high-voltage charge pump increases the output voltage of the original high-voltage charge pump, so that the original high-voltage charge pump can quickly respond to the change of the erase voltage without causing the erase voltage to change too much, and achieve the purpose of precisely controlling the erase voltage

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