I now have a design that needs to collect the output signal of the Rogowski coil.The signal ratio of the coil is 1000A output 88mV, the rated input is 1000A, and can withstand 5 times overcurrent capability (ie 50000A). The signal from the Rogowski coil is amplified and integrated into the ADS8588S.The required accuracy is 0.5 grade accuracy, 5% or less is not required for accuracy, and 5% or more is required to be ±0.5%. The purpose is to obtain the current valid value, and there is no requirement for the phase.
I found a related reference design TIDA-00777 on the official website of TI. There are mainly the following problems.
1、Is there a need to divide the ciruit to two parts，One part is used for zooming in and the other part is used to integrate？
2、The op amp recommended by TIDA-00777 is OPA2188. Can OPA2180 used in my previous project be used to replace OPA2188. The price of both?
3、 Whether the ADS8588S acquisition range needs to be adjusted to ±5V to reduce the magnification？
4、 The structure of the circuit is that the input signal is first amplified, and then integrated. The amplification part is amplified in one step, and can be amplified by 100 times to ±4V(when the range of ADS8588S input is ±5V), or amplified by 200 times ±8V(when the range of ADS8588S input is ±10V), Or The amplification circuit amplifies a part，maybe 50 times, and the integration circuit enlarges a part，maybe 2 times. If you zoom in two levels, how to assign this amplification factor.
5、According to the TIDA-00777 circuit, the amplification part adopts in-phase amplification, and the integral adopts inverse integration. Do you have any better suggestions?
6、Is it necessary to add a protection device TVS tube in the place where the signal is input, and it is ok to use a 5V TVS tube. Still continue to use two 1N4148 parallel.
The above schematic is my design，The first level achieves 76 times magnification，The second level achieves 1.04 times magnification,Is there any problem with this design? Please give me some advice.