Over and under voltage detection circuit

Abstract

The present invention discloses an overvoltage detection circuit. The overvoltage detection circuit comprises an overvoltage reference voltage source, an undervoltage reference voltage source, a power source voltage acquisition module, a logic circuit module, an overvoltage and undervoltage comparison module and a latch module; the logic circuit module comprises a two-input OR gate logic circuit OR1 and a two-input OR gate logic circuit OR2; the overvoltage and undervoltage comparison module comprises an overvoltage comparison module and an undervoltage comparison module; the overvoltage detection circuit integrates an overvoltage circuit and an undervoltage circuit; and an overvoltage point and an undervoltage point both have two threshold voltages, so that it can be ensured that the overvoltage detection circuit can operate stably in the vicinities of an overvoltage threshold point and an undervoltage threshold point. In addition, the overvoltage detection circuit of the present invention is different from an existing mainstream technology according to which hysteresis is realized through feedback, therefore, the response speed of the overvoltage detection circuit is greatly improved.

Description

Technical field [0001] The present invention relates to a protection circuit based on CMOS integrated circuit technology, in particular to an overvoltage and undervoltage detection circuit for detecting overvoltage and undervoltage of a CMOS integrated circuit. Background technique [0002] CMOS integrated circuits are realized by connecting single or multiple functions that are expected to be realized by connecting various devices manufactured on wafers into circuits. CMOS integrated circuits themselves have specific operating voltage ranges. If the given voltage exceeds these The maximum rating of the device will often cause irreversible loss of the chip; [0003] In order to prevent chip damage or damage to peripheral circuits caused by abnormal chip operation, it is usually necessary to set a corresponding safe operating voltage range. If the given voltage is too high or too low, the chip can be protected by its own circuit. [0004] Although the existing overvoltage and undervo...

AI Technical Summary

Problems solved by technology

[0004] Although the existing overvoltage and undervoltage circuits can protect the main control chip by controlling the switch detection module in both overvoltage and undervoltage conditions, the circuit is susceptible to noise interference and is frequently turned on or off at the overvoltage and undervoltage detection points. broken modules, and eventually cause system instability;

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