# BJT Input Diff-Amp Stage/Off-Set Voltage

Define the offset voltage in the op-amp circuits. Show that the expression for the offset-voltage compensation of BJT input diff-amp stage shown in figure 4 is given by:

Vt*ln(ic1/Is3)+ic1R'1=Vt*ln(ic2/Is4)+ic2Rs'

Determine the value of x in the potentiometer to compensate for a mismatch between active load transistors Q3 and Q4. Assume Iq=200uA, Is3=10^-14A, Is4=1.1x10^-14A, R1-R2=2K, Rx=100K

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#### Solution Summary

Define the offset voltage in the op-amp circuits. Show that the expression for the offset-voltage compensation of BJT input diff-amp stage shown in figure 4 is given by: Vt*ln(ic1/Is3)+ic1R'1=Vt*ln(ic2/Is4)+ic2Rs' Determine the value of x in the potentiometer to compensate for a mismatch between active load transistors Q3 and Q4. Assume Iq=200uA, Is3=10^-14A, Is4=1.1x10^-14A, R1-R2=2K, Rx=100K