Note that these filters are subject to aliasing phenomena just like a digital filter, and anti-aliasing filters will usually be required. See: Filter design
Companies such as Linear Technology and Maxim produce integrated circuits that implement this functionality. Filters up to the 8th order may be implemented using a single chip. Some are fully configurable, some are pre-configured, usually as low-pass filters.
Due to the high filter order that can be achieved in an easy and stable manner, single chip analog sampled filters are often used for implementing anti-aliasing filters for digital filters. The analog sampled filter will in its turn need yet another anti-aliasing filter, but this can often be implemented as a simple 1st order low-pass analog filter consisting of one series resistor and one capacitor to ground.
An analogsampledfilter an electronic filter that is a hybrid between an analog and a digitalfilter.
Distinct analogsamples are shifted through an array of holding capacitors as in a bucket brigade.
The analogsampledfilter will in its turn need yet another anti-aliasingfilter, but this can often be implemented as a simple 1st order low-pass analogfilter consisting of one series resistor and one capacitor to ground.
The design of linear analogfilters is for the most part covered in the linear filter section.
The complexity (i.e., steepness) of such filters depends on the required signal to noise ratio and the ratio between the sampling rate and the highest frequency of the signal.
FIR filters are generally easier to design: The Remez exchange algorithm is one suitable method for designing quite good filters semi-automatically.