Patent ID: 7663418

Claim:
An apparatus for compensating slew rate of a driving circuit, the apparatus comprising: a first circuit, for receiving an edge transition from the driving circuit and generating a first pulse proportional to a slope of the edge transition, comprising: a first filter, for generating the first pulse in response to the edge transition; and a first voltage rectifier, coupled to the first filter, for determining the extreme value of amplitude of the first pulse; a second circuit, for receiving an ideal edge transition of the driving circuit and generating a second pulse proportional to an ideal slope of the ideal edge transition, comprising: a second filter, for generating the second pulse in response to the ideal edge transition; and a second voltage rectifier, coupled to the second filter, for determining the extreme value of amplitude of the second pulse; a comparison circuit, coupled to the first circuit and the second circuit, for comparing an extreme value of amplitude of the first pulse with an extreme value of amplitude of the second pulse to produce a comparison signal; and a control circuit, coupled to the comparison circuit, for increasing or decreasing the slew rate of the driving circuit according to the comparison signal.