AAF16/32 Applications

The AAF range of filters provides multiple channels of independent low-pass or anti-aliasing filtering for use before A/D converters or to clarify signals of interest.

When both analogue and digital signals are sampled by an analogue to digital converter, sample & hold or other sampling circuitry, spurious signals are generated if the incoming signal contains frequencies higher than the sample rate. To prevent this low-pass filters are required to remove frequencies less than 50% of the sample rate, or the Niquist frequency.

The filters have unity gain within their pass-band and can be cascaded if required.

Typical applications;

• Place between signal conditioners and A/D’s to prevent spurious A/D readings from aliasing.
• Clarify a signal by removing irrelevant noise.
• Remove frequencies in signals destined for other systems so a lower sample rate can be used for some local task. For example, to obtain variations in load from a component subject to vibration which is being used elsewhere.
• Average sensor signals where the duty cycle of a digital pulse represents its value.
• Apply different filtering to the same input signal to aid analysis.