Voltage detector circuit, high-voltage generator circuit, and semiconductor memory device

According to embodiments of the invention, a high-voltage generator circuit may include a voltage detector block that has a voltage divider, a discharge section, a comparator, and a control signal generator. The voltage divider generates a divided voltage at an output node by dividing a high voltage. The discharge section discharges the high voltage to a power voltage in response to a first control signal. The comparator determines whether the divided voltage reaches a reference voltage, and the control signal generator generates a second control signal in response to an output from the comparator and the first control signal. The voltage divider may include a high-voltage prevention circuit that prevents the high voltage from being applied to a low-voltage transistor of the comparator during a discharge period of the high voltage. The high-voltage prevention circuit may include a depletion-type or enhancement-type NMOS transistor having a high breakdown voltage.