The bipolar diff-amp in Figure 14.22 in the text is biased at \(I_{Q}=500 \mu \mathrm{A}\). Assume all transistors are matched, with \(I_{S}=10^{-14} \mathrm{~A}\). Let \(R_{1}=R_{2}=\) \(500 \Omega\), and assume \(R_{x}\) is a \(50 \mathrm{k} \Omega\) potentiometer. If the wiper arm of the potentiometer is off center such that \(x=15 \mathrm{k} \Omega\) and \((1-x)=35 \mathrm{k} \Omega\), determine the ratio of \(i_{C 1} / i_{C 2}\). What is the corresponding offset voltage?

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ici (3) lo icz Q2 24 Q3 + + VBE3 UBE4 Offset- null terminal ww R RI ww x 1-x ww Rx Offset- null terminal Figure 14.22 Basic bipolar input diff-amp stage, including a pair of offset-null terminals connected to a potentiometer