A high voltage detection circuit for overvoltage protection

Abstract

The invention belongs to the technical field of overvoltage protection, and discloses a high-voltage detection circuit for overvoltage protection, which is characterized by comprising a decoder, an adjustable step-down module and a comparison circuit; the decoder is 3- 8-decoder, including three input ports and seven output ports; the adjustable step-down module for reducing the input high voltage to a low voltage, including the seven-segment step-down circuit, and the seven-segment step-down The circuits are respectively adapted to the seven output ports; the comparison circuit includes a positive feedback loop, and the positive feedback loop includes an inverter and an lvlshift module, and the comparison threshold of the comparison circuit is set based on the lvlshift module, and the adjustable drop is realized. The comparison between the voltage after the step-down of the voltage module and the comparison threshold; to sum up, the present invention can effectively form different degrees of step-down based on the seven-segment step-down circuit, reduce the area of ​​the voltage detection circuit, and make the output result more stable , and also has the effect of improving circuit efficiency.

Description

technical field [0001] The invention belongs to the technical field of overvoltage protection, and in particular relates to a high-voltage detection circuit for overvoltage protection. Background technique [0002] Overvoltage protection means that when the voltage input to the protected circuit is higher than a certain value, the voltage is cut off or suppressed to prevent the protected circuit from being damaged. In the design of electronic circuits, the overvoltage protection circuit is widely placed in the front end of the protected circuit. , in order to achieve effective overvoltage protection. [0003] In the existing overvoltage protection circuit, a voltage comparison type overvoltage protection circuit is included, and in this type of overvoltage protection circuit, the voltage detection circuit is an important part, which is used to detect whether the voltage input to the protected circuit is not If it exceeds the preset value, it will output the corresponding si...

AI Technical Summary

Problems solved by technology

[0005] (1) Resistors are used for voltage division, the output capacity is small, and a slight change in the load will affect the output voltage, and the circuit area is large;

[0006] (2) The resistance consumption is large, which will lead to low circuit efficiency;

[0007] (3) The built-in voltage of the reference source is used as the reference voltage, making it difficult to adjust the reference voltage;

[0008] (4) The driving force of the existing voltage detection circuit is low and the delay time is long

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