Traditional noise analysis only measures device noise impact over time rather than at points within a target period.
Many high-performance analog/mixed-signal ICs include track-and-hold circuits to sample analog signals at one or more discrete timepoints per period. Although track-and-hold circuits are periodic, traditional periodic noise (pnoise) analysis does not apply because it measures the device noise impact integrated over an entire period rather than at instantaneous time points within the target period. A different technique — sampled periodic noise (a.k.a., sampled pnoise) is required. Application areas include analog-to-digital converters (ADC), delta-sigma modulators, and CMOS image sensors.
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