Patent ID: 6087903
Filing Date: 2000-07-11
Classification: H03K,H03L

Abstract:
A voltage-controlled oscillator comprising:an oscillation circuit for producing an oscillated signal, said oscillation circuit comprising a plurality of differential amplifiers connected in a ring pattern,each of said differential amplifiers having a controlled load transistor and being connected in series to first and second parallel current control transistors,said second parallel current transistor having a gate for receiving a current control feedback signal;a control circuit having a drive transistor disposed at an output stage thereof,said drive transistor outputting a control signal to said oscillation circuit to control the frequency of the oscillated signal produced by said oscillation circuit in response to a control voltage applied to said control circuit;a line connecting a gate electrode and one of two opposing end electrodes of said drive transistor to gates of each of said controlled load transistors of said differential amplifiers; anda feedback circuit for controlling current flowing in said differential amplifiers based on a DC voltage of the oscillated signal produced by said oscillation circuit.