Patent ID: 7253676

Claim:
A semiconductor device comprising: a clock generator which generates a clock signal; a booster which boosts a supply voltage by using the clock signal to output an output potential of the booster; a potential detector which detects the output potential of the booster to output a frequency changing signal depending on the output potential of the booster; and a frequency changer which is interposed between the clock generator and the booster to change a frequency of the clock signal from the clock generator to the booster on the basis of the frequency changing signal, wherein the potential detector includes: a voltage-divider which voltage-divides the output potential of the booster to produce a first potential and a second potential which is not more than the first potential, a first comparator which compares the first potential with a reference potential to output the frequency changing signal on the basis of the comparison result, and a second comparator which compares the second potential with the reference potential to output an enabling signal on the basis of the comparison result, said enabling signal determining whether or not the clock signal is caused to pass to the booster from the frequency changer, wherein the semiconductor device further comprises a gate circuit which is interposed between the frequency changer and the booster to cause the clock signal to pass to the booster from the frequency changer or to interrupt the clock signal on the basis of the enabling signal.