meenakshi22
Newbie
I know how to calculate gain via resistance but I don't know how to correlate resistance with tolerance of resistors and degree of mismatch. Can you please help with that. (We can take tolerance of each resistor as 1%.) I have added my work on finding gain(i) Obtain an expression for the CMRR of a difference amplifier, in terms of the tolerance of the resistances used in the amplifier. Hint: Assume that 𝑅1/𝑅2=(𝑅3/𝑅4)(1+𝛼), where 𝛼 is the degree of mismatch. Relate 𝛼 to the tolerance of the resistances (𝜎).
(ii) Plot the relationship between CMRR and 𝜎.
(iii) From the plot obtained in (ii) above, determine the tolerance required for a CMRR of 100 dB.