Method and apparatus for control of a digital phase locked loop (dpll) with exponentially shaped digitally controlled oscillator (dco)

Abstract

Various systems and methods utilizing a digitally controlled oscillator having frequency steps that increase in magnitude as a target output clock frequency increases are described. An integrated circuit in accordance with the disclosure includes a plurality of first transistor units fixedly coupled to an input voltage and a plurality of second transistor units switchably coupled to the first transistor units. An output coupled to the plurality of second transistor units and the plurality of first transistor units conveys an output signal having a frequency dependent on which select ones of the second transistor units are enabled. The plurality of second transistor units include a first switchable transistor unit having a transistor of a first width, a second switchable transistor unit having a transistor of a second width greater than the first width, and a third switchable transistor unit having a transistor of a third width greater than the second width.