I’m reading PAGE35 of ADA4530-1 datasheet about GUARD.
“In practice, the voltage across RSHUNT1 cannot be 0 V, the guard buffer offset voltage contributes to the difference in voltage potential between the A node and VGRD node.”
And the voltage difference between A node and VGRD node will introduce current error.
My question is: Why don’t we use PIN8 as GUARD since the offset of ADA4530 itself is only 50uV, while the GUARD buffer voltage offset is 100uV which is larger.