i am switching voltage levels of 32 channel of a 32 channel multiplexers with the switching speed 20 ms/channel. The range of voltage is 0v to 15 volt..
1st Stage: then after i am passing voltage level through unity gain buffer stage [OPA197]. 2nd Stage then after to reduce the voltage i am using OPA197 in differential configuration.
problem.
1) after unity gain stage i have 40 mV peak to peak noise(HIGH FREQUENCY) in my dc voltage level.
but after deferential amplifier stage it increase to 200 mV peak to peak.
i tried to sort it out using a low pass filter but fail.
here below is my circuit
one thing i observed that the noise is more in low voltage levels such as 200mV 150 mV