| 摘要 |
PURPOSE:To realize high-precision conversion even when the precision of a current source is inferior, by carrying out the conversion by using independent digital analog converters for a positive and a negative side in accordance with the state of the MSB which shows the sign of an input digital signal. CONSTITUTION:When the MSB of an (n+1)-bit input signal is a 1, a switch 39 is on and a switch 40 is off. Then, an (n)-bit signal is inputted to a digital analog converter (DAC)41 and converted into a prescribed analog signal, which is outputted throgh an operational amplifier 47. When the MSB of the (n+1)-bit input signal is a 0, the switch 39 is off and the switch 40 is on. At this time, the (n)-bit input signal is supplied through an inverter to an (n)-bit DAC42, whose output analog signal is inverted by the operational amplifier 47 and then outputted. Thus, two (n)-bit DACs are used to a realize (n+1)-bit DAC. |
