Inverting amplifier

As seen in Section 3.1, the input offset voltage of op-amps can introduce significant output errors. Many op-amps (351, 741) have additional pins for adjusting the offset to zero.

$\parbox{2.0in}{\raisebox{-2.5in}{\par \hbox{\hskip 0in \vbox to 2.5in{\includegraphics[height=2.5in]{FIGS/fig3.3.ps}\vfill}}}}$ $\parbox{3.5in}{% Wire the circuit shown with $R_{f} = 100$ k$\Omega$... ...}$} for five or more values of \mbox{$V_{\rm in}$}, in the range $\pm 0.7$V. }$

$I_{\rm in}$	Calculated $V_{\rm out}$	Measured $V_{\rm out}$	% error

Use the FG set at 1 kHz as $V_{\rm in}$. Use the two channels of the scope to monitor the inverting input of the op-amp and $V_{\rm out}$. Slowly increase the amplitude of the input signal, starting near zero. Observe what happens at the inverting input as the amplifier saturates. Is the assumption of virtual ground still valid?

Keeping the amplitude of the input low and constant, vary its frequency. Can you estimate the maximum slew rate of the 351?