Hi, I am using 8-channel 4051 multiplexer,the o/p of this is connected to CS5532(24 bit sigma delta A/D converter). when only a single channel is selected and converted by the adc it works properly. when more than 1 channel is selected(sequentially ch1-ch2-ch1-..)the effect of 1 signal change is reflected on the other channel o/p as well and vice versa. To avoid this as per the application note i am already rejecting the first five conversions to flush out the residues of previous channel,but this does not solve the problem. please help me with your ideas /suggestions to understand/solve this problem. sujit
if you could guide on how about going with it. I am using a 1mv/V tedea huntleigh loadcell with a total capacity of 600gms and looking to measure 10mg. ie a total of 60K external counts. that is 16 bits of precision, it IS achievable, the cheapest industrial scale I know of that is that precise cost about $8000 and the manual states "calibrate before each weighing".
To get to 16 bits will probably require a 6 or 8 layer board, an autocalibration wiight and circuit. a thermal chanber for some of the components, 4 to 7 ultra stable power supplies, a lot of isolation between analog and digital .....
as I said in an earlier post PPS: if you have any hope of getting above 12 bits (again precision, not resolution) with 'economy' (no 4 layer board etc) I am sorry, but I have to crush that hope.
Erik