Patent ID: 6456134
Filing Date: 2002-09-24
Classification: G11B,H03K

Abstract:
A duty cycle discriminating circuit comprising:an up/down counter with sign bit for counting up or counting down a count clock signal depending on a potential level of a signal to be discriminated; an up counter for counting up said count clock signal regardless of the potential level of the signal to be discriminated; an addend data generating circuit for producing an addend data having a value corresponding to a predetermined proportion of a count value of said up counter; and an addition circuit with sign bit for adding a count value of said up/down counter and said addend data produced by said addend data generating circuit, said sign bit of said addition circuit with sign bit is outputted as a discrimination result signal of said duty cycle discriminating circuit; wherein said predetermined proportion of said count value of said up counter is specified to perform duty cycle discrimination of said signal to be discriminated by using a desired threshold point of duty cycle discrimination.