1.  

A filter is required in order to reduce the high frequency noise at the analogue input of a microcontroller. It is required that all frequencies above 250Hz should be attenuated by a minimum of 20dB per decade of frequency. b) Design a suitable filter to achieve this specification and state any assumptions made. c) After testing it is found that the filter of b) is loading the microcontrollers analogue input. Propose and design a solution to this problem using an active filter configuration.