I am using ADA 4571 IC for angle measurement. I have connected the IC to Data Acquisition Card and observing its output via Lab View. The problem that i am facing is that the two outputs i.e. Sin and Cosin are not out of phase by 90 degree as describe in Data Sheet. So, how can i resolve this do i have to built any external circuitry for making it correct. Kindly, help me how to resolve this problem.