Thank you all for your feedback, its much appreciated!
I’m realizing I did a poor job of explaining the problem, let me try again. Please see the attached figure for a better understanding.
I need to provide a motor and motor driver IC (H-bridge) with a constant 24V. So I have a boost converter providing that 24V to the motor to make sure its a steady 24V. Input to the boost stage is a battery (12V nominal). I also have the INA219B current monitor/ADC from TI that will monitor current to the motor for some data analysis type purposes. The INA219B has a max common mode voltage rating of 26V on the two lines that measure the voltage drop across the sense resistor as shown in the diagram.
My concern is that the INA219B will see 24V nominally, which is within spec by a couple volts. However if there were any transients from the motor turning on/off or the Boost stage momentarily exceeding 26V, I could blow up the INA219B. So I would like to find a way of protecting the sense inputs of the INA219B from seeing anything above 26V.
I could find another way of doing the current monitoring and ditch the INA219B but we have some data that shows the performance of the INA219B is good enough for this application. I don’t have enough data to know exactly what ADC specs are needed to get sufficiently good data for this application (i.e. resolution, sample rate, DNL, INL, etc). So I’m worried about deviating from the INA219B as its the only data point I have so far for a current monitor/ADC that I have confidence will work.
So I feel like I’m stuck between the risk of finding an alternate way of doing current monitoring to ditch the INA219B or risk the INA219B seeing voltages above 26V and damaging the chip. Hence why I’m hoping to find a cleaver way of protecting the INA219B while maintaining the 24V nominal voltage to the motor.
Any thoughts are welcome and much appreciated! I’ve lost too much sleep over this one!