Patent ID: 9306577
Filing Date: 2016-04-05
CPC Classification: H03K,H03L

Claim Text:
1. A digitally controlled oscillator, comprising: a ring oscillator comprising a plurality of stages of delay cells coupled in a circuitous manner, the ring oscillator coupled to a supply voltage and generating a signal oscillated at an oscillating frequency, wherein the oscillating frequency is controlled by a digital code and further varies with a supply voltage drift in a first direction; and a plurality of supplementary circuits, each supplementary circuit comprising a plurality of latches, the supplementary circuit interconnected between successive delay cells and comprising a resistor directly connected between two grounded capacitors, wherein one of the plurality of latches is directly connected to one node of the resistor and another one of the plurality of latches is directly connected to another node of the resistor, said each supplementary circuit facilitating the oscillating frequency to vary with the supply voltage drift in a second direction opposite to the first direction.