Slide 1 Slide 2 Slide 3 Slide 4 Slide 5 Slide 6 Slide 7 Slide 8 Slide 9 Slide 10 Slide 11 Slide 12 Slide 13 Slide 14 Slide 15 Slide 16 Slide 17 Slide 18 Slide 19 Slide 20 Slide 21 Slide 22 Slide 23 Slide 24 Slide 25 Slide 26 Slide 27 Slide 28 Slide 29 Slide 30 Slide 31 Slide 32 Slide 33 Slide 34 Slide 35 Slide 36 Slide 37 Slide 38 Slide 39 Slide 40 Slide 41 Slide 42 Slide 43 Slide 44 Slide 45 Slide 46 Product List
MAX2870-Slide2

This slide will start off by briefly reviewing the basic PLL elements and how it works. The main job of the PLL is to generate a stable high frequency output from a fixed low frequency reference. There are 5 basic blocks that make up a phase-locked loop: the phase frequency detector, the charge pump, the loop filter, the voltage controlled oscillator, and the frequency divider. A phase-locked loop is a negative feedback control system. The system compares the phase of two input signals and produces an error signal proportional to the phase difference. The error signal passes through a loop filter where it is low pass filtered and used to drive the VCO which creates a high frequency output. The VCO output also connects to a frequency divider and fed back to the PFD input. If the output frequency drifts, the phase error signal will increase, driving the frequency in the opposite direction. This action reduces the error until the PLL output is locked to the reference frequency input.

PTM Published on: 2014-02-13