Patent ID: 7948330
Filing Date: 2011-05-24
Classification: H03K,H03L

Abstract:
1. A current-controlled oscillator (ICO) comprising: a first voltage to current converter having an input receiving an input control voltage, and an output for producing a control current inversely proportional to the input control voltage; a first error amplifier having a negative input receiving the input control voltage, a positive input receiving the first voltage to current converter output, and an output producing a bias voltage inversely proportional to the input control voltage; a replica stage having an input receiving the bias voltage from the first error amplifier output, and an output producing a control current equivalent to the first voltage to current converter output control current; and a second error amplifier having a negative input receiving the input control voltage, a positive input coupled to the replica stage output, and an output producing a bias voltage inversely proportional to the first error amplifier output bias voltage, the first error amplifier output and the second error amplifier output forming a pair of regulated symmetric loads to control a bias current of an N-stage current-controlled oscillator.