To precisely generate a plurality of rectangular wave signals having different desired amplitudes without changing the number of adjustment widths of a D/A converter.

A triangular signal generation circuit includes: an integration circuit which integrates an input rectangular wave signal to generate a triangular wave signal; and the D/A converter which drops reference voltage with adjustment widths obtained by equally dividing the reference voltage by a predetermined number, generates a rectangular wave signal with the dropped reference voltage as the amplitude, and inputs the rectangular wave signal to the integration circuit. The A/D converter generates, for each of a plurality of reference voltages, the rectangular wave signals having such different amplitudes that cause the integration circuit to generate the triangular wave signals having desired amplitudes respectively. Accordingly, the A/D converter adjusts a small reference voltage with a small adjustment width when generating the rectangular wave signal having small amplitude, and adjusts a large reference voltage with a large adjustment width when generating the rectangular wave signal having large amplitude to precisely generate the plurality of rectangular wave signals having the different desired amplitudes without changing the number of adjustment widths.