Design of a voltage-controlled oscillator based on MOS capacitance
Xi Wu · Journal of Hefei University of Technology · 2006
The traditional ring voltage-controlled oscillator(VCO)often makes use of the method of controlling resistance to achieve the effect of voltage-controlled oscillation.The capacitive coupled current amplifier is used herein as the basic feedback unit of the VCO and the oscillation frequency is controlled through MOS capacitance in the output.How to use MOS capacitance of saturation region to realize voltage controlling is analyzed.The presented VCO is simulated through the software Smartspice and by adopting the 0.6 μm standard CMOS technologic parameters.The results show that the method has few influence on the static point of the circuit and the frequency stabilization degree of the output AC waveform is high,making this circuit have better linear tuning characteristic.