Power supply input overvoltage undervoltage shutdown controller protection circuit

Abstract

The invention discloses a power supply input overvoltage undervoltage shutdown controller protection circuit including an upper limit voltage detection unit, a lower limit voltage detection unit and a controller power supply unit. When the power supply input voltage exceeds the set upper limit voltage, a NMOS transistor in the upper limit voltage detection unit is switched on, the supply voltage of the controller power supply unit is decreased to zero and thus a power controller does not operate and no power is output. When the power supply input voltage is lower than the set lower limit voltage, a PMOS transistor in the lower limit voltage detection unit is switched off and the supply voltage of the controller power supply unit is decreased to zero and thus the power controller does not operate and no power is output. When the power supply input voltage is between the lower limit voltage and the upper limit voltage, the power is output normally. The power supply circuit is controlled to be switched on or off by the two MOS transistors, and the power supply input overvoltage undervoltage shutdown controller protection circuit is simple in structure, beneficial to the miniaturization of a DC-DC power supply, low in cost and high in reliability, and does not restart a power supply when undervoltage or overvoltage shutdown.

Description

technical field [0001] The invention relates to a power supply input overvoltage and undervoltage shutdown controller protection circuit, which belongs to the technical field of circuits. Background technique [0002] The traditional power overvoltage and undervoltage protection function circuit is generally composed of a reference source, a comparator and a PMOS switch tube. Both the comparator and the reference source need power supply, and the structure is complex. The power input is connected to the PMOS tube in series, and the loss is high. Large; some are composed of two TL431 and PMOS switch tubes, but the cost of TL431 integrated circuits is relatively high. [0003] Name: An overvoltage shutdown protection circuit, application number: 201310656913.4 Chinese patent, single function, does not include the function of undervoltage judgment protection. Name: Under-voltage and over-voltage protection circuit for power circuits, application number: 201310718375.7 Chinese ...

AI Technical Summary

Problems solved by technology

[0002] The traditional power overvoltage and undervoltage protection function circuit is generally composed of a reference source, a comparator and a PMOS switch tube. Both the comparator and the reference source need power supply, and the structure is complex. The power input is connected to the PMOS tube in series, and the loss is high. Large; some are composed of two TL431 and PMOS switch tubes, but the cost of TL431 integrated circuits is relatively high

[0003] Name: An overvoltage shutdown protection circuit, application number: 201310656913.4 Chinese patent, single function, does not include the function of undervoltage judgment protection

Images