Patent ID: 7518437

Claim:
A constant current circuit comprising: a first current setting section of which temperature dependence of a path current indicates first temperature dependence; and a second current setting section connected in parallel with the first current setting section and indicating second temperature dependence corresponding to temperature dependence opposite to the first temperature dependence; and a bias applying section applying bias voltage in substantially no temperature dependence to a connection point of the first current setting section and the second current setting section, wherein currents generated by the first current setting section and the second current setting section are added together and the result of addition is outputted through the bias applying section, either one of the first and second current setting sections includes at least one MOS transistor on a first current path, and other one of the first and second current setting sections is configured so as to have a plurality of resistive elements connected in series on a second current path, and a gate voltage of the at least one MOS transistor provided with either one of the first and second current setting sections is generated by dividing the bias voltage by the resistive elements, wherein the bias applying section comprises: a transistor having a source terminal connected to the connection point; and an amplifier circuit receiving a reference voltage and the bias voltage at the connection point as input signals, the amplifier circuit adjusting controlling a control terminal of the transistor and adjusting the bias voltage at the connection point to the reference voltage.