Control linearity and jitter of relaxation oscillators

The body of this thesis (chapters 3,4 and 5) deals with the analysis and improvement of a specific class of voltage- or current controlled oscillators (VCO’s respectively CCO’s) called relaxation oscillators. Before going into detail on this particular class of oscillators, first the function and application of VCO’s will be discussed. VCO’s are oscillators whose frequency of oscillation is controllable over a wide range by means of a control voltage or current. VCO’s are widely used in applications like phase-locked loops (PLL’s), frequency modulators, frequency synthesisers and timing recovery circuits. As such, VCO’s form an important building block in many data transmission- and processing systems. In these systems, the VCO’s periodical output signal is used e.g. for frequency translation by means of multiplication or extracting data from an incoming modulated carrier signal or bitstream.