Hi all in EE stackchange,
I wonder how the compensating resistor (\$R_3\$) in integrator with DC gain control equals \$R_3 = R_1 || R_2\$, which is to offset effect by the input bias current. I was trying to derive it by same way in Razavi's textbook but I can’t reach the result of compensating resistor \$R_3=R_1 || R_2\$ (As depicted in below Figure) It would be very appreciated if someone let me understand this. Thank you in advance!
