In the [Linear Technology AN 105][1] on current sensing one can find the following circuit.

I am wondering what the purpose of the 200 ohm resistor on the inverting input is. It appears to have no effect.

![enter image description here][2]

Note that in the following paragraph a virtually identical circuit is presented that is lacking said resistor:

![enter image description here][3]


----------


**As a side issue**: is there any downside to sizing the 200 ohm input impedance resistors significantly larger, e.g. 10k? (Keeping gain constant.) The aim would be to reduce the current the opamp draws from its supply to drive the BJT.


----------
## Edit 1: cf Kaz's comment ##

![enter image description here][4]


  [1]: http://cds.linear.com/docs/en/application-note/an105.pdf
  [2]: https://i.sstatic.net/6jduV.jpg
  [3]: https://i.sstatic.net/2Fa7p.jpg
  [4]: https://i.sstatic.net/BfM13.jpg