Patent ID: 8791764
Filing Date: 2014-07-29
Classification: H03K,H03L

Abstract:
1. A digitally controlled oscillator comprising: a ring oscillator having a delay line including a plurality of inverters, wherein each of the inverters is connected between a first delay power supply node and a second delay power supply node; and a first variable resistance bank connected between the first delay power supply node and a first power supply voltage terminal and having a variable resistance value varied under the control of n bits of a control code, wherein a frequency of a clock signal output by the ring oscillator is based on the resistance value of the variable resistance bank, wherein the frequency of the clock signal output by the ring oscillator changes substantially proportional to a number of active bits of the control code, and wherein a relationship between the number of active bits of the control code and the reciprocal of the resistance value is non-linear and wherein a relationship between the reciprocal of the resistance value and the frequency of the output clock signal is non-linear.