Level shift circuit capable of suppressing noise

Abstract

The invention discloses a level shift circuit capable of suppressing noise, comprising a floating power supply, a dipulse generation circuit, a high-voltage level shift circuit, an undervoltage detection circuit, an RS latch circuit, a drive circuit, a differential mode current detection circuit and a differential mode noise elimination circuit, wherein the differential mode current detection circuit is used for suppressing a common mode current signal output by the high-voltage level shift circuit, detecting a differential mode current signal, converting the differential mode current signal into a differential mode voltage signal and outputting the differential mode voltage signal to the differential mode noise elimination circuit; and the differential mode noise elimination circuit is used for receiving the differential mode voltage signal output by the differential mode current detection circuit, eliminating differential mode noise introduced by the mismatching of the high-voltage level shift circuit, converting the differential mode voltage signal into a high-end reset signal and a high-end position signal and outputting the two signals to the RS latch circuit. The invention not only can be used for suppressing the common mode noise, but also can be used for eliminating the differential mode noise and has the advantages of simple circuit structures, chip area saving and convenient popularization and use.

Description

technical field [0001] The invention belongs to the technical field of analog integrated circuits, in particular to a level shift circuit capable of suppressing noise. Background technique [0002] In traditional electronic ballasts, a transformer is generally used to drive an inverter circuit. Using a transformer to drive the inverter circuit not only consumes a lot of power and occupies a large area, but also has poor switching characteristics. The level shift circuit integrated on-chip can transmit the low-voltage control signal to the high-voltage drive circuit without the need of a traditional transformer, and generate the required high-voltage drive signal, which can save power consumption and area, and has better switching characteristics. [0003] However, the integrated level shift circuit on-chip is powered by the floating power supply. When the high-end power tube is turned on, the floating power supply VB and VS change drastically. The road introduces spike noi...

AI Technical Summary

Problems solved by technology

The level shift circuit used in high-voltage integrated circuits is realized by two fully matched level shift branches, one branch is used for setting, and the other branch is used for clearing. If the set branch of the level shift circuit There is a process deviation between the clearing branch and the clearing branch, and the noise introduced by one branch of the level shift will make the other branch lose its function, which will cause erroneous logic, which will have a very bad effect on the high-voltage integrated circuit and the external power transistor. influences

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