Patent ID: 7990300
Filing Date: 2011-08-02
Classification: H03M

Abstract:
1. A D/A conversion circuit comprising: a reference current setting unit that sets a reference current; and a current cell output unit comprising a plurality of constant-current sources, the constant-current sources being configured to output currents corresponding to the reference current, the current cell output unit being configured to generate an analog voltage signal generated from an analog current signal obtained by adding up output currents from the constant-current sources according to a value of an input digital signal, wherein the reference current setting unit comprises: a reference current source that generates the reference current; a first resistive element through which the reference current flows; a second resistive element through which the reference current flows; a selection control circuit that, when an amplitude level of the analog voltage signal is to be changed, selects at least one of the first and second resistive elements and connects the selected resistive element to the reference current source; and a reference current control circuit that controls a current amount of a reference current of the reference current source according to a voltage generated by a resistive element selected from among the first and second resistive elements.