US Patent 7928880 Digital analog converter

A digital analog converter has an input terminal receiving a digital input signal, a lower-side capacitor group coupled to a lower-side common terminal in parallel, an upper-side capacitor group coupled, in parallel, to an upper-side common terminal at which an analog output signal is generated, a coupling capacitor provided between the lower-side common terminal and the upper-side common terminal, a switch group coupled to the upper-side capacitor group and the lower-side capacitor group and controlled as a conduction state and a non-conduction state in accordance with the digital input signal, and an adjusting capacitor coupled to the lower-side common terminal and having a variable capacitance value.