Patent ID: 8049539

Claim:
A circuit with variation correction function comprising: an actual operation circuit which receives a voltage control signal and outputs an oscillation signal having a frequency corresponding to the voltage control signal, and which includes a to-be-corrected element, wherein the actual operation circuit is a voltage control oscillator, which includes a resonance circuit receiving the voltage control signal; and a correction circuit which is structured separately from the actual operation circuit, uses a signal which is not related to the voltage control signal as the reference signal, and outputs a control signal reflecting manufacturing characteristic variations to the actual operation circuit without being affected by an operation condition of the actual operation circuit, wherein the control signal is not fed back to the correction circuit; wherein the actual operation circuit and the correction circuit are arranged in one chip, and the manufacturing characteristic variations of the to-be-corrected element in the actual operation circuit are corrected for operation by the control signal outputted from the correction circuit, and wherein the correction circuit includes: a dummy circuit which is constituted by an element structured same as the to-be-corrected element and receives an input of a reference signal; and a conversion circuit which outputs the control signal based on an output signal of the dummy circuit.