| 摘要 |
PURPOSE:To speed up the titled converter, by providing two systems of output terminals as analog current output terminals of a D/A converter in providing A/D, D/A mode switching function, for switching the modes without using an analog switch. CONSTITUTION:The D/A converter 19 has two output terminals 17, 18 with no mutual interference. Further, when a mode selecting terminal is ''L'', a serial digital signal inputted from a digital input terminal 24 is inputted to a successive comparison register 21, converted into a parallel data, inputted to the D/A converter 19, outputted to an analog output terminal 26 from an output terminal 17 via an operational amplifier 25, and the D/A conversion is done. When the state of a terminal 23 is ''H'' inversely, a switch 22 passes a signal comparing a voltage depending on a current flowing from an analog input terminal 27 to the output terminal of the D/A converter 19 and a ground potential, through a successive comparison register, the signal is converted successively and outputted to a parallel digital output terminal 30 for the A/D conversion. |
