Voltage detector circuit

A voltage detector circuit comprising:

• a power supply voltage monitor that is equipped with first and second resistors coupled between a first terminal and a second terminal, and that generates a monitored voltage resulting from dividing a power supply voltage, which is supplied from the first terminal, based on a resistance ratio between the first and second resistors;
• a power supply voltage rising ramp detector that monitors the rising rapidity of the power supply voltage, and that generates a boost signal which is enabled for a certain period, if the power supply voltage rises faster than a preset rapidity to trigger operation switching;
• a resistance switching circuit that is equipped with a third resistor which is coupled in parallel with the first resistor and a fourth resistor which is coupled in parallel with the second resistor, and that makes the third and fourth resistors active during a period when the boost signal is enabled;
• and
• a comparator that compares the monitored voltage with a reference voltage, and that outputs a voltage detection signal indicating that the power supply voltage has exceeded a predetermined voltage value.