Assuming perfectly matched resistances in the difference amplifier of Fig. 2.13a, show that if we define the CMRR of the op amp as 1/CMRROA = aVoslauCM(OA) and that of the difference amplifier as 1/CMRRDA = Acm/Adm, where Acm = aUdaucM(DA) and Aim = R2/R, we then have CMRRDA = CMRROA. %3D FIGURE 2.13 (a) Difference amplifier. (b) Expressing the inputs in terms of the common-mode and differential-mode components uCM and UDM- R1 R2 R R2 VDM VCM 2 OVo O Vo VDM R3 (= R) 2 V2 R4(= R2) R3(= R,) R, (= R2) (a) (b)