Voltage level conversion circuit

Abstract

To make a voltage level converting circuit, which converts an input signal having a logical voltage level corresponding to a high power supply voltage VDD1 into a signal having a logical voltage level corresponding to a low supply voltage VDD2 and outputs it, operable at the lower low supply voltage VDD2. A power source level converting circuit comprises a level converting portion for converting an input signal of a VDD1 system to a signal of a VDD2 system and a NOT circuit 30 for reversing the level converted input signal and outputting it. Outputs of NOT circuits and of the VDD1 system constituting the level converting portion 101a are inputted only into high breakdown voltage transistors Qhn1 and Qhp2 in the level converting portion . A signal having a logical voltage level corresponding to the low supply voltage VDD2 is inputted in low breakdown voltage transistors Qln1 and Qlp2 in the level converting portion . Furthermore, only the level converted input signal from the level converting portion is inputted into the NOT circuit at post-stage of the level converting portion .

Description

technical field [0001] The present invention relates to a voltage level conversion circuit, in particular to converting an input signal having a logic voltage level corresponding to a first power supply voltage into a logic voltage level corresponding to a second power supply voltage lower than the first power supply voltage After the output signal is output, the voltage level conversion circuit is output. Background technique [0002] In recent years, with miniaturization of semiconductor devices, two types of voltages, an external voltage and an internal voltage, are used, and the internal voltage is set lower than the external voltage. Therefore, a circuit for converting the logic voltage level of a signal is required between a circuit driven by an external voltage and a circuit driven by an internal voltage. [0003] Hereinafter, conventional art will be described with respect to a circuit (hereinafter referred to as a voltage level conversion circuit) that converts a l...

AI Technical Summary

Problems solved by technology

[0024] As mentioned above, in Image 6 In the conventional voltage level conversion circuit 201 composed of two-stage negation circuits shown, since the subsequent negation circuit using the low power supply voltage VDD2 as the power supply voltage is composed of VDD1 withstand voltage series (high voltage series) transistors, the transistor's The threshold voltage is high, and it is difficult to operate this high-voltage series transistor with a low power supply voltage lower than the threshold voltage

Therefore, there is a problem that such a voltage level conversion circuit 201 constitutes a factor that prevents the reduction of power consumption by low-voltage driving in semiconductor devices or the miniaturization of transistors.

[0025] in addition, Figure 7 The illustrated level shifting circuit 202, as described above, is considered to be a circuit that converts a logic voltage level corresponding to a low power supply voltage to a logic voltage level corresponding to a high power supply voltage. In the case where the circuit structure is applied to a voltage level conversion circuit that converts a logic voltage level corresponding to a high power supply voltage into a logic voltage level corresponding to a low power supply voltage, the transistor 13 that applies a logic voltage corresponding to a high power supply voltage It is a high-voltage transistor with a thick gate oxide film, so there is a problem that the threshold value of a transistor with a low power supply voltage cannot be lower than that of a transistor with a high power supply voltage as a withstand voltage

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