Anti-Alias Filter with Zeroes at Multiples of the Sampling Frequency
Publication Date: 2003-Jul-09
The IP.com Prior Art Database
An analog anti-alias filter, with zeroes at multiples of an Analog to Digital Converter (ADC) sampling frequency, processes analog data prior to the ADC. The anti-alias filter may be implemented as a first, second, third, fourth, fifth, or higher order analog filter, and may be optimized to provide a flat group-delay (assuming ideal components) from DC through the cut-off frequency and beyond. The anti-alias filter includes a sample-and-hold (S&H) circuit that may serve as a first stage of a Successive Approximation (SA) ADC. As with standard analog anti-alias filters, the anti-alias filter may derive additional benefits from over-sampling and digital decimation.