PERIODIC SIGNAL GENERATING CIRCUIT

摘要

PURPOSE: A periodic signal generating circuit is provided to offer a periodic signal which has a uniform period regardless of the change of temperature by compensating the physical change of a transistor due to the change of temperature. CONSTITUTION: A reference voltage generating part generates a reference voltage which has an output level being varied according to temperature. A periodic cycle signal generating part(200) offers a periodical signal in response to the level of a set voltage deciding a reference voltage and an oscillation period. A differential amplifying part(220) offers an oscillation control signal by sensing the voltage difference between the set voltage and the reference voltage. An oscillating part(240) offers a periodical signal in response to the oscillation control signal. A charge and discharge part(260) charges or discharges the set voltage in response to the output signal of the reference voltage and the oscillating part.