Undervoltage detection circuit and detection method

Abstract

The present application discloses an undervoltage detection circuit and detection method, including a power supply, a state machine, a decoding control circuit, a sampling voltage divider network, and a voltage comparison circuit; the state machine is connected to the power supply and the output end of the voltage comparison circuit; the input and output ends of the decoding control circuit are respectively connected to the output end of the state machine and the input end of the sampling voltage divider network to generate a control code; the sampling voltage divider network is connected to the power supply, and the voltage divider ratio is changed by the state code of the decoding control circuit, and the power supply is divided according to the voltage divider ratio; the output of the sampling voltage divider network is connected to the input end of the voltage comparison circuit, and the input voltage divider voltage is compared with the reference voltage to obtain output feedback. This scheme adds a state machine to the circuit structure, dynamically adjusts the voltage divider ratio according to the state machine and the sampling voltage divider network, outputs the voltage divider voltage closest to the reference voltage, and can adapt to a variety of low-voltage environments, adaptively adjust the voltage divider ratio of the power supply, and improve the precision and accuracy of undervoltage detection.

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