Patent ID: 7385542

Claim:
A waveform generating module for outputting a pair of synchronous analog signals, comprising: a first digital filter for generating a first converted signal into which a first digital signal, which represents a signal value of a first analog signal to be outputted, is converted on the basis of a first filter coefficient; a second digital filter for generating a second converted signal into which a second digital signal, which represents a signal value of a second analog signal to be outputted, is converted on the basis of a second filter coefficient; a DA converter for converting said first and second digital signals into said first and second analog signals at a predetermined time interval respectively; and a correcting filter coefficient generator for generating said second filter coefficient correcting a skew, besides a waveform of an impulse response of said correcting filter coefficient is same as said first digital filter, on the basis of said skew of a timing with which said DA converter converts said first and second digital signals into said first and second analog signals and said first filter coefficient.