| 摘要 |
PURPOSE:To pick up a differential voltage directly and to simplify the circuit, by picking up the voltage with a resistor between current sources flowing in or out corresponding to a digital signal, in an A/D converter converting the voltage difference of two analog signals. CONSTITUTION:Corresponding to a digital signal given to terminals C-E of a register 1, a voltage corresponding to the digital signal is produced across a resistor 4 between current sources 2, 3 to which the same current flows out or in, the voltage is added to or subtracted from the 1st analog voltage V1, and it is compared with the 2nd analog signal V2 so that the digital signal when the two are in a prescribed relation is picked up as the A/D conversion value corresponding to the difference between the 1st and 2nd analog signals V1 and V2. Thus, other circuits such as subtraction circuit and the like are not required and a digital signal for the voltage difference can directly be obtained. |
