multiple feedback filters
Hi,
I came across reading an application note (sloa064:
**broken link removed**) by Texas Instrument which is relevant to the differential op-amp circuit. There is this multiple feedback filters which introduces the filter for full-differential op-amp. I do not quite understand about the schematic.
There are two R1 (R1A, R1B), two R2 (R2A, R2B), two R3 (R3A, R3B), two C1 (C1A, C1B), and two C2 (C2A, C2B). My question is: how do I calculate for the resistance and capacitance value, take the Bessel filter for example. The R1 in the formula is referring to a combination resistance value of R1 and R2, or single value of R1 and R2?
Thanks.