Just a quick question about an application circuit in the LTC1966 datasheet.
Figure 13 on page 18 shows a third order (when considering output resistance of the LTC1966) Sallen-Key filter, with a resistor RB between the non-inverting input and the output of the op amp.
What is the purpose of this resistor? It doesn't exist on any Sallen-Key schematics I can find, and the datasheet just gives us two values for their measurements - 294K and 0R, with no other information.
The schematic in question:
Can anyone shed any light on the purpose of this resistor?