Patent ID: 8120429
Filing Date: 2012-02-21
Classification: H03K,H03L

Abstract:
1. A voltage-controlled oscillator (“VCO”) circuit comprising: a plurality of VCO cells coupled to each other in a loop; and control circuitry coupled to a source of relatively high voltage and operable to generate a control input signal of said plurality of VCO cells, wherein: said plurality of VCO cells is operable to receive a gear input signal; a delay through at least one of said VCO cells is based on a voltage of said control input signal, and a capacitive load on an output signal of said at least one of said VCO cells is based on a voltage of said gear input signal; when said gear input signal is in a first state, output of said VCO circuit has a first phase noise characteristic, and varying said control input signal varies frequency of said output of said VCO circuit within a first range having a starting point; and when said gear input signal is in a second state, output of said VCO circuit has a second phase noise characteristic noisier than said first phase noise characteristic, and varying said control input signal varies frequency of said output of said VCO circuit within a second range having said starting point, wherein the second range is larger than said first range.