| 摘要 |
<p>PURPOSE:To reduce noise by controlling a current summation type A/D converter with a gradient linear data obtained at a differential arithmetic circuit and interpolating data between adjacent sampling points corresponding to the gradient data. CONSTITUTION:When a differential arithmetic circuit 3 fetches a data (b) at a sampling point t2 from a demodulation circuit 1, the circuit 3 fetches a data (a) at a sampling point t1 at a just preceding time from a tentative hold circuit 2 simultaneously to calculate a gradient [(b-a)/(t2-t1)] and the polarity of the gradient based on a difference (b-a) of both the data. Then a digital data of each point on a straight line l1 from the data (a) to the data (b) based on the calculation. Then the current summation type A/D converter 4 controls a sum current in response to the consecutive data change to apply A/D conversion to the data.</p> |
