An extended frequency range CMOS voltage-controlled oscillator

This paper presents an extended frequency range CMOS monolithic voltage-controlled oscillator (VCO) design. A negative feedback control algorithm is used to automatically adjust the VCO range according to the control voltage. Based on this analog feedback control algorithm, the VCO achieves a wide range without any pre-register settings. Low phase noise is achieved by using both coarse control and fine control in the VCO. A 600 MHz to 3.3 GHz monolithic CMOS PLL, based on this wide range and low phase noise VCO, has been fabricated in TSMC 0.18 /spl mu/m, 1.8 V CMOS technology and is used in many different applications such as FC, GE, and SONET etc.