A voltage detection circuit

Abstract

The invention provides a voltage detecting circuit which comprises a voltage division circuit, an isolating circuit, a comparison voltage generation circuit and a comparison circuit. A sample voltage signal after power supply voltage division is transmitted to the comparison voltage generation circuit through the isolating circuit, and two comparison voltage signals are generated in the comparison voltage generation circuit and are compared by the comparison circuit to output a logic signal, so that power supply voltage is detected. In the voltage detecting circuit, a reference voltage generation circuit does not need to be additionally added, the voltage detecting circuit is simple in structure and overcomes the shortcoming that a traditional voltage detecting circuit is affected by factors such as accuracy of reference voltage provided by the outside world and the matching degree of ratios of divider resistors, and a trip point of the comparison circuit of the voltage detecting circuit cannot be affected by current and temperature in the divider resistors and is only related to the power supply voltage, so that detecting accuracy of the voltage detecting circuit is improved.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a voltage detection circuit. Background technique [0002] In an integrated circuit system, when the power supply voltage introduced from the outside of the chip is insufficient, the chip will not work normally. Therefore, a voltage detection circuit is generally added inside the chip to detect the power supply voltage and output a corresponding logic signal to make the chip enter a corresponding state to ensure the normal operation of the chip. [0003] The voltage detection circuit in the prior art generally uses a comparison circuit to directly compare the supply voltage with the reference voltage, so as to obtain a corresponding logic signal to realize voltage detection and make the system enter a corresponding state. [0004] Please refer to figure 1 , which is an existing voltage detection circuit, the power supply voltage VDD in the voltage divider circuit 102 is divid...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a voltage detection circuit to solve the problem that the voltage detection circuit in the prior art is affected by the accuracy of the reference voltage provided by the outside and the matching degree of the voltage dividing resistor ratio, resulting in the accuracy of detection when detecting the power supply voltage. not high problem

Images