A 3.3-V CURRENT-CONTROLLED ROOT-DOMAIN OSCILLATOR

In this paper, the strong inversion MOS analog of the recently propose d class of log-domain filters, or translinear filters, is proposed. Th e dynamic root-domain principle, or dynamic voltage-translinear princi ple, exploits the quadratic law, describing the MOS transistor in the strong inversion region, both to perform an expanding V-I conversion o f the capacitor voltages and to implement multiplications and square r oots of currents based on the voltage-translinear principle. The prese nted theory is applied to the design of a current-controlled two-integ rator oscillator. Experiment results of a pure CMOS test IC show the f easibility of the root-domain principle. The realized oscillator has a THD of -42 dB and is linearly frequency tunable across 1.3 decades.