| 摘要 |
<p>PURPOSE:To simply attain equivalent automatic gain control by providing a parallel comparison type A/D converter comprising plural comparators connected in parallel, an encoder, a latch buffer circuit and a reference voltage circuit or the like. CONSTITUTION:A parallel comparison type A/D converter 4 consists of plural comparators 21-27 connected in parallel, an encoder 28, a latch buffer circuit 29 and a reference voltage circuit 30. Then the circuit 30 includes resistors R1, R2, R3, R4, R5, R6, R7, R8, divides a voltage between 1st and 2nd terminals 37, 38 and supplies the result to the comparators 21-27. For example, a control voltage is applied from an output terminal of an integration circuit to, e.g. a 2nd terminal 38 and a 1st terminal 37 connects to a power supply. Thus, the potential of reference voltage lines 31-36 is changed by a change in the potential of the 2nd terminal 38. Then the conversion sensitivity of the A/D converter is changed automatically with a simple circuit configuration to obtain the similar effect, to be given by the automatic gain control(AGC).</p> |
