TIDA-01471: Some questions about 4-channel vibration interface schematic

Hello,

Here is the thread discussing the 4 channel case including simplified schematic. Hope this works as a starting point for your design.

https://e2e.ti.com/support/tools/sim-hw-system-design/f/234/p/776823/2879325?tisearch=e2e-sitesearch&keymatch=TIDA-01471#2879325

Regareds,

Ahmed

Hello Ivan,

This schematic snippet represents a variable gain stage using a switchable resistors in the feedback path. You can omit it (better for noise and linearity) and use simple fixed gain stage. Same IS also valid for the variable attenuation stage at the front.

Now comparing your target spec with the design, i may give those comments:

1- the TIDA has 20k BW. You will need to modify the filter stage to reduce the BW to 12k

2- the Design is Sampling at 64k, you need to configure the ADC to sample at 128k instead.

3- as you require a variable current, i do recommend the cascaded opamp architecture described in

I hope this helps.

Regards,

Ahmed