Analog DEMUX

[deepakvnit]

hi all, i am using HEF4051 as  address decoder and to send analog voltage through that channel now what i am doing is to send address bit and after that some analog voltage to be sent in that channel. i need to use all the channel simultaneously so connected capacitors to hold the value for few milliseconds. i first send address bit after that analog voltage and then address of next channel and its analog value and keep on doing it in a loop.Thus all values get refreshed after a particular time interval.
    Now my problem is that when i do so i didn't get the voltage retained by capacitors. After some efforts i got voltage to be retained but it is the average voltage of  the channels not the needed voltage, So can anyone explain this why is this happening and solution as well. thanx in advance!!!!!

[Nishant_Sood]

After some efforts i got voltage to be retained but it is the average voltage of  the channels not the needed voltage, So can anyone explain this why is this happening and solution as well. thanx in advance!!!!!

The answer is pretty straight forward , The capacitor is accumulating the current and then smoothifying (the various values in the analog reading) the flow thus the average is coming out of it and read , if you drop the capacitor then i think you may get things right but only have to care about timing and reading it at the righteous time.

[Sandeep_Raj]

Ok.. At first.. a capacitor is a voltage dependent device. It has nothing to do with the current.


I dont understand your problem completely. Did you switch the Enable to OFF state? How are you reading the analog values? Serial monitor??
Do you have a ckt diagram which u can attach??