LMP91000: Value of resistor and capacitor connected between C1 and C2 pin

Chithkala,

What goes between C1 and C2 depends on the chemical cell you are using. Depending on the cell and how its current output looks, you can add an external resistor for a custom gain or an external capacitor to add in active low pass filtering. If the internally programmable gain options are acceptable, then you don't need an external gain resistor. If you want to use an external gain resistor, make sure to set the gain of R_TIA to "External", and just choose a R_EXT value that gives the desired voltage output. Once you do that, if you see noise on the signal, you can add a C_EXT across C1 and C2 as well, which can filter out high frequency. The capacitor value you choose will determine which frequencies are filtered out. So it really is up to you and how your signal looks.

Regards

-Alex Thompson