Other Parts Discussed in Thread: ADC3643EVM, , INAEVM-ALT-SO8, ADC3643
Hello TI Team,
I am currently working on the INA849 that I would like to use to feed the input of an ADC3643EVM board.
It is connected to a square wave generator with typical amplitude below 50 mV and a 1us with very sharp edges. I used the regular application schematic of the INAEVM-ALT-SO8 board :
I didn't show the input section as it is part of a design subjected to confidentiality, but lets just say that the differential input voltage is very low in amplitude, so that the instrumentation amplifier output is not saturating.
Despite the output low pass filter, I get very large overshooting spikes lower than 100 ns wide and higher than 100% in voltage amplitude, that would be damaging to the ADC input. I tried lowering the filter cutoff frequency but it resulted in an increase of the overshoot recovery time, while the overshoot rising remained sensibly the same.
Do you have any suggestion to remove, or at least very significantly tame the overshoot, so that the input of the ADC remains safe ? Also, what would be the best approach to protect the ADC input, would a simple Shottky diode be sufficient ?