An electronic device including: a regulator circuit configured to output a regulated voltage based on a reference voltage and a feedback voltage; and an oscillator configured to generate an output frequency signal based on a reference frequency signal and the regulated voltage output from the regulator circuit, wherein the regulator circuit includes: a feedback loop configured to output the regulated voltage based on a difference between the reference voltage and the feedback voltage; a first capacitor; a precharge circuit connected to the feedback loop, and configured to charge the first capacitor with a second voltage which is based on a first voltage; a first switch configured to connect the precharge circuit with the first capacitor; and a second switch configured to connect the first capacitor with the feedback loop.