Patent ID: 8405429
Filing Date: 2013-03-26
Classification: G06F,H03K

Abstract:
1. A power supply voltage monitor circuit comprising: a constant voltage circuit receiving a power supply voltage and outputting a first constant voltage; a level shift circuit receiving the first constant voltage and outputting a second constant voltage obtained by subjecting the first constant voltage to level shift; a clamping circuit receiving the first constant voltage and fixing the received first constant voltage at a clamping voltage; a first differential circuit including a second differential circuit which, in a case where the clamping circuit does not fix the first constant voltage, turns off the current source of the differential unit depending on a potential difference between the first constant voltage and the first input voltage to control the output operation of the output unit, whereas in a case where the clamping circuit fixes the first constant voltage, turns on the current source of the differential unit depending on a potential difference between the clamping voltage and the first input voltage.