| 摘要 |
A capacitive commutating filter provides a D. C. output voltage of amplitude responsive to the amplitude of an input waveform having a frequency substantially equal to the operating frequency of the filter. The filter operating frequency is established by a digital signal. The filter input is selectively and cyclically connected through N input resistances, wherein N is an integer greater than zero, to adjacently progressive N ones of (2N+1) nodes, each having one of (2N+1) capacitive filter elements connected to ground potential. The equilibrium voltages across the capacitive filter elements, established during the N/(2N+1) segments of the input waveform during which each capacitor is connected to the input, are coupled to one set each of maximum-positive-polarity and maximum-negative-polarity diodes, for placing the maximum and minimum filter capacitive element voltages at respective ones of the inverting and non-inverting inputs of a differential amplifier, having the output thereof forming the filter output.
|
