CONVERTER

PURPOSE:To vary an analog variable simultaneously with D/A conversion by varying a constant current supplied to a D/A converter to a required current value. CONSTITUTION:Transistors (TRs) Q1, Q2 constitute a current mirror circuit and its input-side current I1 can be optionally set up by a variable resistor VR. When the input-side current I1 is varied by setting the variable resistor VR, an output-side current IOUT is also changed in accordance with the change of the input side current I1. On the other hand, TRs Q11-Q14 constitute a current mirror circuit and said output side current IOUT becomes the input-side current of the current mirror circuit constituted of the TRs Q11-Q14. Therefore, the sum of currents flowing into the TRs Q12-Q14 is varied in accordance with said variation of the output-side current IOUT.