Analogue filter circuit for use in PAM data receiver system

摘要

The circuitry consists of an analogue filter (3), as part of a receiver (9), two analog switches (1, 2), and a micro-controller (6) with an oscillator (7) and auxiliary oscillator. The analogue switches are coupled to the filter and the oscillator inputs (4, 5) of the controller. With the receiver activated, the analogue switches are opened for disconnecting the filter from the oscillator inputs. With the receiver deactivated, the analogue switches are made to connect the filter to the oscillator inputs of the micro-controller. If coupled to the filter, the oscillator operates at the filter resonance frequency and serves for generating a time base.