Patent ID: 8242809
Filing Date: 2012-08-14
Classification: H03K

Abstract:
1. A comparator circuit, comprising: first and second terminals to which a reference voltage that determines a threshold voltage is inputted; a third terminal to which a standard voltage is inputted; a fourth terminal to which a target voltage that is to be detected and is based on the standard voltage is inputted; first and second transistors of a first conductivity type including control terminals connected to the first and second terminals, respectively, the first and second transistors flowing currents depending on a potential difference of the reference voltage; a third transistor of a second conductivity type connected in series with the first transistor; a fourth transistor of the second conductivity type connected in series with the second transistor; a fifth transistor of the second conductivity type through which a mirror current flows depending on a current flowing through the third transistor; a sixth transistor of the second conductivity type flowing a mirror current depending on a current flowing through the fourth transistor; a seventh transistor of the first conductivity type connected between the sixth transistor and the fourth terminal; and an eighth transistor of the first conductivity type connected between the fifth transistor and the third terminal, the eighth transistor flowing a mirror current depending on a current passing through the seventh transistor, wherein a voltage depending on a voltage of an intermediate node between the fifth and eighth transistors is outputted as an output signal.