Voltage level shift circuit

Abstract

The invention discloses a voltage level shift circuit comprising a voltage clamping unit operating between the highest level voltage and a first low level voltage of a first system power supply, a current-limiting circuit coupled to the second low level voltage of the first system power supply, and a single power switching transistor coupled to the voltage clamping unit and the current-limiting circuit, wherein the first low level voltage is higher than the second low level voltage. When the single power switching transistor is not turned on, the output voltage is pulled up to the highest level voltage of the first system power supply; when the single power switching transistor is powered on, the current-limiting circuit limits the breakover current of the single power switching transistor to a value not exceeding a current upper limit, the condition that the voltage clamping unit does not need to be provided with the other high withstand power transistor is ensured, and thus the output voltage is clamped at the first low level voltage.

Description

technical field [0001] The invention relates to a voltage level shift circuit, in particular to a voltage level shift circuit. Background technique [0002] For integrated circuits under different power supply environments, the judgment of their logic values ​​is not the same. For an integrated circuit that uses a system power supply voltage range of 0V to 5V, when judging the logic value, when the signal voltage level is 0V, the logic value is judged as 0; when the signal voltage level is 5V, the logic value is judged is 1. Taking the system power supply voltage range from 0V to 60V used in analog integrated circuits for power management as an example, when judging the logic value, when the signal voltage level is 0V, the logic value is judged to be 0; when the signal voltage level is 60V, the judgment logic value is 1. When these two integrated circuits are used in combination, such as Figure 8 As shown, a voltage level shift circuit 52 must be connected in series to s...

AI Technical Summary

Problems solved by technology

As the component density of integrated circuits increases, it is not conducive to the use of components with too large layout area. For the voltage level shift circuit commonly used in integrated circuits, it also faces the same challenge and must be further improved.

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