Patent ID: 8436687

Claim:
An oscillating apparatus comprising: a band gap circuit including a first PNP transistor having a base and a collector coupled to a reference potential node respectively, a second PNP transistor having a base and a collector coupled to the reference potential node respectively, and a first resistor coupled to an emitter of the second PNP transistor at one end, wherein the band gap circuit generates a band gap voltage by controlling a potential at the other end of the first resistor so that it becomes equal to an emitter potential of the first PNP transistor; a transfer gate including a P-channel transistor and a N-channel transistor; a reference current generation circuit that generates reference currents by summing a positive dependence current and a negative dependence current, the reference current generation circuit includes a positive dependence current generation circuit for generating a positive dependence current that has a positive dependence on absolute temperature, the positive dependence current generation circuit includes a third PNP transistor having a collector and a base coupled to the reference potential node respectively, a second resistor coupled to an emitter of the third PNP transistor at one end, and a first control circuit for controlling a positive dependence current flowing through the second resistor in such a way that a potential of the other end of the second resistor becomes equal to the band gap voltage, and a negative dependence current generation circuit for generating a negative dependence current that has a negative dependence on absolute temperature, the negative dependence current generation circuit includes a third resistor coupled to the reference potential node at one end, and a second control circuit for controlling a negative dependence current flowing through the third resistor in such a way that a potential of the other end of the third resistor becomes equal to the emitter potential of the first PNP transistor; and a trimming current digital-to-analog conversion circuit that generates a bias current on the basis of the reference currents, wherein a gate voltage corresponding to the bias current are applied to each of the gates of the P-channel transistor and the N-channel transistor, and transfer gate outputs a signal at an input-terminal of the transfer gate from an output-terminal of the transfer gate in accordance with the gate voltage of each of the P-channel transistor and the N-channel transistor.