Low jitter VCO design examples

In this chapter we will examine two design examples. The first one, a single- ended CMOS ring oscillator, illustrates general design techniques and trends, specifically highlighting the sizing dependance of jitter parameters in CMOS. The second example, a differential bipolar ring oscillator, examines the design of a bipolar VCO for a specific low jitter PLL application, illustrating some of the design considerations of the VCO within the framework of the larger system. The two examples were chosen for their generality and coverage of the key concepts developed in this book. Extension to specific designs can be easily made based on the methodology of the previous chapter and the examples given in this chapter.