Power detection circuit and method

Abstract

The invention provides a power detection circuit and method. The power detection circuit comprises a power supply switching module which is switched on or switched off according to power-on or brown-out condition; a voltage division sampling module for sampling a power supply voltage; a voltage comparison module for carrying out power-on detection; a brown-out detection module for carrying out brown-out detection; and a pulse latching module for latching a voltage rising edge transmitted by the voltage comparison module and a low level transmitted by the brown-out detection module. The methodcomprises the steps of switching on the power supply voltage, carrying out voltage division sampling on the power supply voltage and carrying out power-on detection on a signal obtained through voltage division sampling; carrying out power-on detection on the power supply voltage; outputting a first logic level if the power-on is finished, and carrying out delayed output to ensure that a system works stably; and outputting a second logic level if the brown-out occurs. The power detection circuit and method have a power-on detection function; after the power-on is finished, no power consumptionexists; and the detection precision of the power detection circuit and method is far higher than that of the prior art.

Description

technical field [0001] The invention relates to the field of analog integrated circuits, in particular to a power supply detection circuit and method. Background technique [0002] In an integrated circuit system, digital circuits located on a chip, such as control units and registers, will be in an uncertain state during power-on. Therefore, a circuit is needed to initialize and reset these uncertain states to ensure that the entire system of the chip can work normally. Usually, we use a power-on reset circuit (POR: Power-on-Reset) to achieve this function: before the power supply voltage is at the voltage threshold for the normal operation of the digital circuit, the POR set signal makes the digital circuit in a fixed initialization State; after the power supply voltage rises to the threshold voltage, the POR set signal is released, and the digital circuit can work normally. [0003] A reliable power-on reset circuit (POR) needs to meet the following requirements: 1) The...

AI Technical Summary

Problems solved by technology

[0008] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a power detection circuit and method for solving the problems of low detection accuracy, lack of power-down detection function, and power consumption in the power-on reset circuit in the prior art. major issues

Images