| 摘要 |
<P>PROBLEM TO BE SOLVED: To drastically improve SNR of an AD conversion output signal by compensating so as to suppress accumulation of quantization error in the AD conversion device including a differential amplifier circuit. <P>SOLUTION: An AD conversion device comprises a differential amplifier circuit 1A, an AD converter 3A, and a digital demodulation circuit 4A. Subtracters 42 and 52 subtract analog signals from DA converters 41 and 51, which perform DA conversion on a digital signal from the AD converter 3A into an analog signal, from analog output signals from the differential amplifier circuit 1A, and output a subtraction result signal indicating quantization error of the AD converter 3A. The AD converter 30 performs AD conversion on the subtraction result signal from the subtracters 42 and 52 into a digital signal. Adders 43 and 53 compensate so that the quantization error becomes substantially zero by adding the digital signal from the AD converter 30 to the digital signal from the AD converter 3A, and output an addition result signal to the digital demodulation circuit 4A. <P>COPYRIGHT: (C)2012,JPO&INPIT |
