The amplifier of FIGURE 1 has a closed loop gain of 20 dB and R = 10 k_. The resistors have a tolerance of 5%.
a.Estimate the output offset voltage of the circuit of FIGURE 1 when
the op-amp used is
- i)op-amp A of TABLE A
ii)op-amp B of TABLE A.
b.If the circuit of FIGURE 1 uses op-amp A of TABLE A, show how the output offset voltage can be reduced by a circuit modification, calculating the value of any components used.
c.Explain why the technique used in (b) above is relatively ineffectual if op-amp B of TABLE A is used.
N.B. The output offset voltage is given by the equation: