Power source voltage detection circuit and control method thereof

Abstract

The invention discloses a power source voltage detection circuit which comprises a power source bleeder circuit, a comparator input switching circuit, a voltage comparison circuit and a logic control module. The voltage comparison circuit comprises an overvoltage comparator and an undervoltage comparator. The comparator input switching circuit is respectively connected with the power source bleeder circuit, the voltage comparison circuit and the logic control module and can enable the input signals of the voltage comparison circuit to be switched between output signals of the power source bleeder circuit and the logic control module. An input end of the logic control module receives output signals of the voltage comparison circuit and enables the output signals of the overvoltage comparator to be reversed and fed back to an input end of the overvoltage comparator, and the in-phase signals of the output signals of the undervoltage comparator are fed back to the input end of the undervoltage comparator. The invention further discloses a control method of the power source voltage detection circuit. When the power source voltage detection circuit is invaded by a physical bypass, further operation of a chip can be controlled, and safety of the chip can be ensured.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuits, in particular to a power supply voltage detection circuit. The invention also relates to a control method of the power supply voltage detection circuit. Background technique [0002] High-end security smart card chips are mainly used in banking and other fields: such as credit cards, bank cards, smart card-type bank cards have electronic wallets, electronic passbooks, and can store cash for offline transactions, so the smart card has a very high or even the highest security requirements. At present, the temperature detection, voltage detection, frequency detection and light detection modules of this type of security chip are standard configurations of this type of chip. The purpose is to ensure that the working conditions of this type of security chip meet the working range of the circuit, so as to prevent user data Erase and write by mistake, and also prevent criminals from usi...

AI Technical Summary

Problems solved by technology

At present, the temperature detection, voltage detection, frequency detection and light detection modules of this type of security chip are standard configurations of this type of chip. The purpose is to ensure that the working conditions of this type of security chip meet the working range of the circuit, so as to prevent user data Erase and write by mistake, and also prevent criminals from using it to obtain the confidential data of customers, copying and misappropriating it to cause damage to legitimate users

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