Summation of band-limited ADC outputs having different resolutions and rates

摘要

A high speed analog-to-digital converter utilizes a fine resolution ADC to digitize the low band component of an analog video signal to produce a fine resolution signal and a coarse resolution ADC to digitize the full spectrum of the analog signal and produce a coarse resolution signal. The coarse resolution signal is subtracted from the fine resolution signal to generate a summed signal containing a quantization error, which is filtered through a low pass digital filter to filter out the high band component and pass the quantization error. The filter output is summed with the coarse resolution signal to restore the fine resolution of the low band, producing a digital output signal that has a resolution suitable for high definition applications.