| 摘要 |
PURPOSE:To attain A/D conversion with high accuracy by combining a D/A converter and a differential amplifier to an A/D converter. CONSTITUTION:An electric switch 2 is connected normally to a terminal 2a, an input analog signal voltage V1 is multiplied by b-times at an amplifier 13, converted into a digital quantity at the 1st A/D converter 4 and read to a processor 5 via a register 10. An output of the register 10 is given also to a D/A converter 11, and the 2nd analog signal converted into analog quantity by the converter 11 is given to an invertig input of a differential amplifier 12 and an output of the amplifier 13 is given to a non-inverting input of the amplifier 12. The signal difference between the output of the amplifier 13 and the output of the converter 11 is multiplied by (d) as the output of the amplifier 12, it is converted into a digital signal by the 2nd A/D converter 14 and inputted to the processor 5. The processor 5 operates the output signal of the converters 4, 14 and gives an output while erasing the error of the converter 4. |
