Patent ID: 7548131

Claim:
An oscillation circuit comprising; a temperature-dependent current source being configured to output a control voltage based on a current flowing into a transistor corresponding to an ambient temperature; a first logic gate and a second logic gate being configured to output a second level of output signal when both of two input signals have a first level and to output said first level of said output signal when one or both of said two input signals have said second level, wherein the output side of said first logic gate is connected to the first input side of said second logic gate and the output side of said second logic gate is connected to the first input side of said first logic gate; a first delay circuit being configured to start charging or discharging of a capacitor corresponding to said control voltage when the output signal of said second logic gate is changed from said second level to said first level, and provide the second input side of said first logic gate with a pulse of said second level when the voltage of said capacitor reaches to a threshold voltage depending on the ambient temperature; and a second delay circuit being configured to start charging or discharging of a capacitor corresponding to said control voltage when the output signal of said first logic gate is changed from said second level to said first level, and provide the second input side of said second logic gate with a pulse of said second level when the voltage of said capacitor reaches to a threshold voltage depending on the ambient temperature; further comprising a constant voltage source being configured to provide said first and second logic gates and said first and second delay circuits with a given constant power supply voltage.