Iam using 8 channel analog MUX SN74HC4851, in a temperature reading application.
Here there are 24 NTC thermister to read with one MCU analog pin , using 3 MUX.
In my circuit all channel selection pins and common output pin s are connected parallel, and MUX selection is done by ENABLE pin separately, and read all MUX sequently.
My problem is , suppose channel 1 of MUX 1 is HIGH, and all other channels LOW practically…But corresponding pin of MUX 2 also shows high.I use proper delay and all other precautions, but no use. Individual MUX gives good values in all channels
Please give me the error possibilities.
below attached my schimatic.
There , output signal conditioning , MCU and thermister circutary are omitted