DC analog signal

[maduba]

Hi,

I would like a advice on how to filter out the DC analog signal that comes out from analog multiplexer. It contains noice kind of spike. I very much appreciated if you could reply me back soon as possible. Thank you

 

[danadak]

A cap in series with output will remove DC.

Do you have a scope capoture of spike waveform ? If its real
narrow a LPF sill help remove it. But what is signal into mux,
range of frequencies ? Can you show a scope capture of normal
signal with spike ?

So a series cap with above low pass filter, at ist input, will remove DC.
The filter the spike.....

RC Low-pass Filter Design Tool

Regards, Dana.

 

[rjenkinsgb]

The simplest way to eliminate switching spikes or glitches is to bias all the signals to the same DC level around the multiplexer.

eg. This is an example I did for another user, but the exact same principle applies with a multiplexer; consider the three switches as a three way multiplexer & adjust the number of input bias caps and resistors to suit.

 

[danadak]

Some considerations in using analog switches and causes of transients -

https://www.analog.com/media/en/training-seminars/tutorials/MT-088.pdf

Performance Optimization of Multichannel Data Acquisition (DAQ) Systems: The Untold Story of the Input Settling Time | Analog Devices

This article will describe how settling time delay, caused by a switching transient at the input of the multiplexer, causes prolonged acquisition time and/or conversion errors, effectively decreasing the overall throughput of the multi-channel data acquisition system.

www.analog.com

Regards, Dana.

 

[AnalogKid]

Please post your schematic so we can analyze the circuit behavior.

ak