| 摘要 |
PURPOSE:To realize a compact A/D converter, by installing a variable gain amplifier, a logical circuit and an A/D converter within an integrated circuit. CONSTITUTION:An A/D converting unit 1 is formed within a single chip in the form of an integrated circuit. Then a signal designating a range of voltage is applied to a terminal 8 to be decided by a logical circuit 7. Then a switch 5-1 is turned on to connect a resistance R1 to an operational amplifier 4 and to set the gain of a variable gain amplifier 3 to a prescribed value. Then the voltage is applied to an input terminal 6 to be amplified by the amplifier 3. This amplified voltage is converted into a signal equivalent to the rated level of an A/D converter 2 and then converted into a digital signal by the converter 2 to be delivered through a terminal 9. |
