Stability of the UV sensor

AN4451

10/15

DocID025985 Rev 1

A second order equation can be deduced as shown in formula (12).

So, we can deduce the minimum feedback capacitance of Cf to guaranty stability of the

OA1MPA, is shown in formula (13).

In this application, GBP = 120 kHz, Cg = 103 pF, and Rf = 8.2 MΩ. Using formula (13), we

can calculate that the minimum feedback capacitance of Cf is 4.2 pF.