A-type leakage protector allowing leakage tripping current values to stay same

Abstract

The invention discloses an A-type leakage protector allowing leakage tripping current values to stay the same. The A-type leakage protector is formed by integrating a chopper stabilizing zero operational amplifier, a hysteresis comparator, a digital processing module and a ring oscillator on the same chip, wherein the chopper stabilizing zero operational amplifier is used for reducing offset voltage of a CMOS operational amplifier and amplifying A-type leakage induction signals; the hysteresis comparator is used for comparing the amplified A-type leakage induction signals with different A-type leakage signal comparative levels and producing corresponding leakage comparison pulses; the digital processing module is used for recognizing A-type leakage signals and producing trip signals; the ring oscillator provided with a tail current source is used for providing modulating signals for the chopper stabilizing zero operational amplifier and providing a clock for the digital processing module. The A-type leakage protector can be effectively prevented from being triggered by mistake; from triggering timing, several types of leakage waveforms are sequentially detected within subsequent successive time periods and do not interfere with each other even if the leakage waveforms are not in a standard form; due to detection within the time periods, the interference rejection of the leakage protector is also improved, and the leakage tripping current values are allowed to stay the same; accordingly, the leakage protector has prospects of market application.

Description

technical field [0001] The invention relates to the field of integrated circuit design, in particular to an A-type leakage protector with consistent A-type leakage tripping current values. Background technique [0002] With the advancement of science and technology and the continuous development of the economy, people's living standards have been greatly improved, and electrical equipment is becoming more and more complex, especially electrical equipment with a large number of electronic components. Such as computers, electronic office appliances and household appliances are increasing, and there are more and more non-sinusoidal AC residual currents in electrical circuits. Traditional AC-type residual current protectors can only ensure tripping for sudden or slowly rising residual sinusoidal alternating currents, so common AC-type residual current protectors can no longer meet the requirements. [0003] Type A leakage protector is a leakage protector that can ensure reliabl...

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Problems solved by technology

[0005] The Chinese patent document with the publication number CN102130440A discloses an ASIC chip for a type A leakage protector. The chip is too simple to judge the type of A type leakage, and the discreteness of the tripping current values ​​of different types of A type leakage is large, which cannot satisfy The practical requirements for consistent tripping current values ​​result in weak anti-interference ability of A-type leakage protectors, which are not suitable for market application

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