Patent ID: 6650191
Filing Date: 2003-11-18
Classification: H03K

Abstract:
A ring oscillator, having a first, second, and third power supply rail, comprising:a first capacitor coupled between the first power supply rail and the bias voltage input; and at least one stage coupled across the first capacitor comprising, a first transistor having a gate, a drain, and a source, the drain coupled to the first power supply, the gate coupled to the bias voltage input, a second capacitor coupled between the source of the first transistor and the third power supply rail, and a fully symmetrical differential delay cell, having a control input, a differential input and a differential output, the source of the first transistor coupled to the control input to apply a supply voltage, wherein, when one stage is present, the differential inputs couple to the differential outputs, wherein, when more than one stage is present such that a first and a last stage exists, the differential outputs of each delay cell coupled to the differential inputs of the delay cell in the concurrent stage, and the differential outputs of the delay cell in the last stage couples to the differential inputs of the delay cell in the first stage.