Step-by-Step Noise Analysis Guide for Your Signal Chain |
This article presents the steps needed to carry out a theoretical analysis on the noise performance for a high speed wide bandwidth signal chain. Although a specific signal chain is chosen for the analysis, the steps highlighted can be considered valid for any type of signal chain. Five main phases are suggested: declaring the assumptions, drawing a simplified schematic of the chain signal, calculating the equivalent noise bandwidth for each of the signal chain blocks, calculating the noise contribution at the output of the signal chain for all blocks, and adding all noise contributions. The analysis shows how simple math can be used to describe all noise contributions. Gaining an understanding of how each block contributes to the overall noise allows the designer to appropriately modify the design (for example, choice of components) to optimize its noise performance.