D-A CONVERTER AND SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE WITH BUILT-IN D-A CONVERTER

摘要

PROBLEM TO BE SOLVED: To provide a D-A converter capable of realizing a sufficient output voltage accuracy by suppressing a differentiated linear error in association with relative irregularity of a constant current circuit to a small value by preferentially using a constant current source circuit for a more significant bit.;SOLUTION: At a node N1, another end of a switch S2 is connected to a constant current source circuit I2 one bit more significant, another end of a switch S4 is connected to a constant current source circuit I3 two bits more significant and another end of a switch S7 is connected to a constant current source circuit I4 three bits more significant. At nodes N2 and N3, the switches are similarly connected. At the node N2, switches S5 and S8 are connected to the circuit I3 one bit more significant and to the circuit I4 two bits more significant. At the node N2, a switch S9 is connected to the circuit I4 one bit more significant. These switches are controlled to be preferentially used from the more significant node and to be preferentially used from the constant current source circuit for the more significant node according to an internal control signal based on the input signal.;COPYRIGHT: (C)2002,JPO