Method of Unlocking Low-Voltage Protection Cooperating with Power-off Delay

Abstract

The invention discloses a method for realizing low-voltage protection unlocking in conjunction with power-off delay, and the system enters the low-voltage protection state: S1, detecting the system voltage; S2, judging whether the current voltage is greater than the set start-up voltage V1, and if so, entering S4; otherwise, entering S3 ;S3, record the detected system voltage as the previous voltage, and return to S1; S4, judge whether the previous voltage is less than the set low-voltage protection threshold Vt, if so, enter S5; otherwise, enter S3; S5, turn on the power supply, and set the error flag Clear it to restore the system to normal, and enter S1; Steps S1-S5 run in a loop until the system chip is completely powered off or unlocked successfully. The invention realizes the unlocking of the low-voltage protection for the system which unlocks the protection only when the machine is switched on and off quickly but not when the battery voltage recovers. The present invention solves the problem that the system may fail to start when the battery voltage is not restored when the power is turned on and off quickly in conjunction with the delay time of power failure without increasing structural hardware.

Description

technical field [0001] The invention relates to low-voltage protection, in particular to a method for realizing unlocking of low-voltage protection in cooperation with power-off delay. Background technique [0002] For embedded development, in order to prevent the jitter of the power supply terminal in the system, capacitors are often added to reduce the instability of power supply, but due to the existence of capacitors, there will be a certain delay when the system is powered off. The MCU powered by 5V also slowly drops to the voltage that stops working due to the presence of capacitors, and the software stops running completely, that is, there is a delay between the power-off of the system and the complete stop of the software, which is called the power-off delay of the software here. . [0003] There is generally a low-voltage protection function in the system, which generally protects the voltage connected to the system, which is called the system voltage, and the powe...

AI Technical Summary

Problems solved by technology

However, for the requirement of "after the system reaches the low-voltage protection, turn off the system power supply, even if the power supply is restored, the system will not be turned on unless it is turned on and off again", neither of the above two methods can meet the requirements.

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