I have a confusion regarding how to remove DC offset in ECG/EMG amplifer, which is said to be around 300mV. I came up with 2 different techniques:
A. Instrumentation amplifier followed by a 1st order RC high pass filter
B. Instrumentation amplifier with ac-coupling (output fed back through an integrator to the reference pin of IN-amp)
With both techniques, I got similar result: couldn't get higher gain than ~10. So what is the advantage of B over A ?
I found a design with high gain of 100: Figure 69 on the data sheet. But it seems like I cannot use common mode feedback as DRL.
Could someone suggest me how to get higher gain from IN-amp ? Can I just use a RC HPF before the inputs of IN-amp?