Patent ID: 7852130

Claim:
A voltage detection circuit comprising: a voltage detection section configured to output a first signal when detecting a downward transition of a supplied voltage to a relatively low level equal to or lower than a first voltage or output a second signal when detecting said supplied voltage in a state of being higher than said first voltage and when detecting an upward transition of said supplied voltage to a relatively high level higher than a second voltage higher than said first voltage after said downward transition of said supplied voltage to said relatively low level equal to or lower than said first voltage; a first voltage determination section configured to put a first transistor in a turned-on state by making use of said second signal output by said voltage detection section so as to put a second transistor in a turned-off state in order to set a fraction of said supplied voltage at a first value so as to generate a first fractional voltage, which is to be actually compared with a voltage determined in advance in order to determine whether or not said supplied voltage itself is equal to or lower than said first voltage, in accordance with a first voltage ratio; and a second voltage determination section configured to put said first transistor in a turned-off state by making use of said first signal output by said voltage detection section so as to put said second transistor in a turned-on state in order to set a fraction of said supplied voltage at a second value smaller than said first value so as to generate a second fractional voltage, which is to be actually compared with said voltage determined in advance in order to determine whether or not said supplied voltage itself is higher than said second voltage, in accordance with a second voltage ratio.