This paper will present a practical and complete analysis of timing-mismatch effects for high-speed Analog Front-End (AFE) systems with the inherent nonuniformly holding outputs. The analysis reveals first the relationship with traditional impulse-sampled timing-mismatch effects and then its closed-form expressions of the signal-to-noise-ratio (SNR), in terms of the number of channels, signal frequency, and jitter errors. Both timing errors imposed by random clock-jitter and fixed periodic clock-skew will be analyzed. Practical analysis examples for a very high-speed data-converter as well as a AFE filtering will be addressed to illustrate the effectiveness of the derived formula.