Patent ID: 9019020
Filing Date: 2015-04-28
Classification: H03K,H03L

Abstract:
1. A digitally-controlled oscillator (DCO), comprising: a base frequency generator having an odd number of base inverters connected end-to-end to generate an output signal that oscillates at a predetermined frequency; and a frequency-adjusting unit connected to the base frequency generator, the frequency-adjusting unit including a first string of switchable inverters connected in series with each other, the switchable inverters having sizes that decrease from an input end of the first string to an output end of the first string; wherein the first string of switchable inverters includes a first switchable inverter configured to receive an input signal, a second switchable inverter configured to receive an output from the first switchable inverter, and a third switchable inverter configured to receive an output from the second switchable inverter; the second switchable inverter is smaller than the first switchable inverter, and the third switchable inverter is smaller than the second switchable inverter; and the second switchable inverter is X percent smaller than the first switchable inverter, and the third switchable inverter is Y percent smaller than the first switchable inverter, where X is a number between around 5 and around 15, and Y equals X+X/2.