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
4051 multiplexer,the o/p of this is connected to CS5532(24 bit this makes absolutotally no sense, you are using an extremely imprecise multiplexer in front of a 24 bit A.D??? Do you even have an inkling of understanding what you are doing? Erik
OK. So the Hardware is wrong. Thanks for solving part of my problem. But can you please suggest an alternative design or A/D converter. Here's what my problem is. I need to sample 4 analog channels sequentially (ch1-ch2-ch3-ch4-ch1-ch2...) all of which are weigh scale signals and based on this i need to do some set-point based output control.(channels and thier control are independent of each other) I had till this point tested the complete application for a single channel and it worked perfectly but the multiplexing part didn't work. I Know there is a 4 channel A/D conerter from the same family(CS5534), but i was not able to get it out there. Can you suggest any other A/D converter which can be used in this application(with internal mux or with compatible external mux). a 16-bit ADC might also be sufficent. thanks, sujit
I had till this point tested the complete application for a single channel and it worked perfectly but the multiplexing part didn't work. So if you were only sampling a single channel, signal changes in the other three channels had no effect on the one channel you were sampling ? Can you suggest any other A/D converter which can be used in this application(with internal mux or with compatible external mux). a 16-bit ADC might also be sufficent. Have a look at Analog Devices' ADuC8xx series.
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