Automatic reset detection circuit for power up and power failure

Abstract

The invention discloses an automatic reset detection circuit for power up and power failure. The circuit comprises a power supply detection circuit (1), a band-gap reference circuit (2), a voltage comparator (3), a ring-shaped RC (remote control) oscillator (4) and an M-bit counter (5), wherein the power supply detection circuit (1) is used for detecting change of power supply voltage, when the power supply voltage is higher than preset threshold voltage, the voltage comparator (3) outputs a high voltage level, the ring-shaped RC oscillator (4) and the M-bit counter (5) begin to work, after 2M periods, an output Reset signal is changed to the high voltage level, and the power up reset detection is completed; when the power supply voltage is lower than the preset threshold voltage, the voltage comparator (3) outputs a low voltage level, the ring-shaped RC oscillator (4) and the M-bit counter (5) stop working, the output Reset signal is changed to the low voltage level, and the power failure reset detection is completed. The automatic reset detection circuit is simple in structure and easy to implement, and further has the power up and power failure reset detection functions simultaneously.

Description

technical field [0001] The invention mainly relates to the design field of automatic reset detection circuit for power-on and power-off, in particular to an automatic reset detection circuit for power-on and power-off. Background technique [0002] Electronic products based on integrated circuits need to judge the power supply voltage when the system is powered on to ensure that the system works at a safe voltage. For example, when using batteries, fuel cells, solar cells or generators, it is possible that the power supplied by the power supply is insufficient, resulting in slow power-up or failure to reach the voltage for stable operation of the system. In this way, some circuits in the circuit may work, and the It will cause errors and accelerate the aging and damage of the chip. Therefore, when the power supply voltage exceeds the operating conditions of the equipment, an accurate and reliable method for initializing and shutting down the circuit is very important. Duri...

AI Technical Summary

Problems solved by technology

For example, when using batteries, fuel cells, solar cells or generators, it is possible that the power provided by the power supply is insufficient, resulting in slow power-up or failure to reach the voltage for stable operation of the system. In this way, some circuits in the circuit may work, and the Will lead to errors, accelerate the aging and damage of the chip

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