Sampling Jitter in Audio A/D Converters

Abstract

This paper provides an overview of the effects of timing jitter in audio sampling analog-to-digital converters (ADCs), i.e. PCM (conventional or Nyquist sampling) ADCs and sigma-delta (Σ∆) ADCs. Jitter in a digital audio is often defined as shortterm fluctuations of the sampling instants of a digital signal from their ideal positions in time. The influence of the jitter increases particularly with the improvements in both resolution and sampling rate of today's audio ADCs. At higher frequencies of the input signals the sampling jitter becomes a dominant factor in limiting the ADCs performance in terms of signal-to-noise ratio (SNR) and dynamic range (DR).

Timing Jitter Analysis and Mitigation in Hybrid OFDM-DFMA PONs

“…In any DSP-based system including DACs/ADCs, timing jitter is mainly caused by the thermal noise and thermal vibrations of the semiconductor crystal structure of sampling clocks used to drive the DACs and ADCs which lead to random fluctuations of their clock signal edges from their ideal positions [10]- [12]. Also, internally induced aperture jitter is prevalent in practical ADCs, this is caused by the uncertainty of the aperture time during disconnecting the hold capacitor from the input buffer amplifier inside the sample-and-hold circuit when switching from the sample mode to the hold mode [13], [14].…”