Your design looks good, but the use of RC filtering at the output of your op amps would be benefitial, the RC filter behaves as a charge bucket filter. These components help recharge the internal sample and hold capacitor of the ADC. These componenets have to be sized correctly to make sure that the ADC input settles. This cookbook circuit explains the design of your application: Circuit for Driving High Voltage SAR ADCs for High-Voltage , the example uses a different ADC, but can be applied to this one as well. We also have a Precision Labs video that talk about how to select the RC filter values. These videos also guides you on how to simulate the input into the ADC, these simulations can help confirm that your ADC input settles. In this video, the Analog Engineer's calculator is used, this is a great tool that canhelp narrow down the value selection for the RC. It also has many other helpful calculations. I know this seems like a lot of material, but one builds on the other, I would suggest reading the cookbook circuit first. Then, using the analog calculator to narrow down the RC filter, From there, simulate. this will give you confidence about how the circuit behaves. Regards Cynthia
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