I'm designing a voltage measurement device and I i'm testing it and the front end voltage divider and it has a much lower voltage than expected. Circuit is below.
So I put in 5V (real world) input across R1 (10Meg) and R2 (10Meg) I only see 384.6mV between them?? I expect to see 2.5V. What have I done wrong and how do I fix it?
p.s dont simulate the schematic its just representation
Thank you for the input, I have found the issue and its a novice mistake which took me awhile to find. I've updated the schematic. See im using R2 and R9 to attenuate the input voltage, but I did not take into account the OFF resistance of M1 and M2, which I have measured to be 0.9Mohm, so obviously most of my voltage is being dropped in R9 and M2.