Patent ID: 7782151
Filing Date: 2010-08-24
Classification: H03L

Abstract:
1. An extended range voltage controlled oscillator (VCO) circuit for use in a phase-locked loop (PLL) circuit, the VCO circuit comprising: (a) a VCO including: (b) a control circuit including: (c) a first bank of switched capacitors arranged in parallel for use in one half of the VCO circuit, and a second bank of switched capacitors arranged in parallel for use in the other half of the VCO circuit, wherein the capacitors in a respective bank of capacitors that are switched on coarsely determine the VCO center frequency, the first pair of varactors providing a fine adjustment of the VCO center frequency, and wherein during the first state, the control circuit further outputs signals for use in selecting the capacitors to switch on in the respective banks of capacitors.