Patent ID: 6384620
Filing Date: 2002-05-07
Classification: H03K

Abstract:
A signal deciding apparatus comprising:an amplifying circuit which has a plurality of inverting amplifiers that are mutually serially connected and is used for converting an AC input signal into a binary digital signal; and a feedback path which is used for feeding back an output signal of said amplifying circuit to an input signal thereof in order to set a threshold value for binary decision of said amplifying circuit and is equipped with a first integrating circuit for prevention of an oscillation that is caused due to the feedback signal, wherein said feedback path has: a second integrating circuit for integrating an output signal of one of said inverting amplifiers locating at an odd number stage when it is seen from an input side of said amplifying circuit by a predetermined time constant; a third integrating circuit for integrating an output signal of one of said inverting amplifiers locating at an even number stage when it is seen from the input side of said amplifying circuit by a time constant larger than the time constant of said second integrating circuit; a comparing circuit for comparing output voltages of both of said integrating circuits and supplying an output voltage to said first integrating circuit; and a control circuit for applying a control voltage for setting a threshold voltage to an input terminal of said comparing circuit for receiving the output voltage of said third integrating circuit.