| 摘要 |
PURPOSE:To perform both analog-to-digital conversion and digital-to-analog conversion by providing a D/A conversion part and comparator, a digital signal generation part and one-way control gate, and a two-way control gate. CONSTITUTION:The conversion analog output of a D/A conversion part 1 is compared with an input analog signal from a terminal 4 by a comparator 3, whose comparison output is used to control a digital signal generation part 5. Its digital output is supplied to the input side of a D/A conversion part 1 through a one-way control gate 15. The digital input of the D/A conversion part 1 is coupled to a digital signal external terminal 17 through a two-way control gate 16. Then when the gate 15 is opened, an input analog signal is converted into a digital signal, which is outputted to the external terminal 17 through the gate 16, thus obtaining the function of an A/D converter. On the other hand, the gate 15 is closed to supply a digital signal from the external terminal 17 to the D/A conversion part 1, obtaining the function of a D/A converter. |
