Power supply voltage detection device

摘要

A power supply voltage detection device includes a reference voltage generating circuit (14), an integrator circuit (15), a lower limit comparator (11), and an upper limit comparator (12). The reference voltage generating circuit generates lower and upper limit reference voltages by resistance-dividing a power supply voltage. The integrator circuit integrates comparative voltages extracted by resistance-dividing the power supply voltage. The lower limit comparator compares the lower limit reference voltage from the reference voltage generating circuit with an output voltage from the integrator circuit to detect that the power supply voltage becomes equal to or lower than a lower limit. The upper limit comparator compares the upper reference voltage from the reference voltage generating circuit with an output voltage from the integrator circuit to detect that the power supply voltage becomes equal to or higher than an upper limit. <IMAGE>