Patent ID: 8587707

Claim:
A digital-analog (DA) converter comprising: a reference current generating circuit that generates a reference current; a plurality of current sources that supply currents according to the reference current; a voltage output circuit that outputs a voltage according to a current to be supplied thereto; a plurality of switch circuits provided for the current sources respectively to each switch a connection of each of the current sources to the voltage output circuit or a predetermined load; a control section that controls the plurality of switch circuits based on an input digital signal to select that of the plurality of current sources which is to be connected to the voltage output circuit, and outputs a voltage according to the digital signal from the voltage output circuit; a switch, different from the plurality of switch circuits, that stops an operation of one of the plurality of current sources based on a control signal from the control section, without stopping an operation of the reference current generating circuit, said switch being electrically disposed between the one of the plurality of current sources and a corresponding one of the plurality of switch circuits; a current transfer circuit electrically disposed between the voltage output circuit and the reference current generating circuit that suppresses an influence of the stop of the operation of the one of the plurality of current sources on the reference current or another of the plurality of current sources; an offset regulating current source that supplies a positive current or a negative current to the voltage output circuit to correct an offset level; and a switch that stops an operation of the offset regulating current source based on a control signal from the control section, wherein the plurality of current sources include a first current source with a current value according to the reference current, and a plurality of second current sources with current values proportional to the current value of the first current source, the switch stops an operation of the first current source, the current transfer circuit includes a first current transfer circuit electrically disposed between the first current source and the reference current generating circuit that suppresses the influence of the stop of the first current source on the reference current, and the current transfer circuit includes a second current transfer circuit electrically disposed between the offset regulating current source and the reference current generating circuit that suppresses the influence of the stop of an operation of the offset regulating current source on the reference current.