| 摘要 |
PURPOSE:To obtain high operation stability against large level variation, and to simplify LSI-implementation, by using a variable linear A/D converter for a data transmission system. CONSTITUTION:An analog input signal is supplied via sample holding circuit 32 to variable linear A/D converter 31, whose output is analogized through series-parallel converter 33 and outputted as a digital signal. In order to feed back the output signal of converter 31, some of the output signal is supplied to D/A converter 37 of converter 31 via level supervisory circuit 25 and multplier generating circuit 26. Then, converter 31 attains linear companding operation by being equipped with comparator 34, sequential comparison logic circuit 35 which receives some of its output, and multiplying D/A converter 36 which gives the comparator a signal varying the quantizing step of the output of circuit 35 corresponding to the output of converter 37. |
